Clinical, cytological, and histopathological features of canine lipomas: a retrospective study in Espírito Santo, Brazil

Clinical, cytological, and histopathological features of canine lipomas: a retrospective study in Espírito Santo, Brazil | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Short Report Clinical, cytological, and histopathological features of canine lipomas: a retrospective study in Espírito Santo, Brazil Eduarda Pereira Andrade, Lorenzo Martinelli, Amanda Trevizani Soares, and 9 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9336078/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 4 You are reading this latest preprint version Abstract This study aimed to characterize the epidemiological, cytological, and histopathological aspects of canine lipomas diagnosed in Espírito Santo, Brazil. A retrospective analysis was conducted on 175 canine lipoma cases diagnosed between 2018 and 2024 at the Veterinary Pathology Laboratory in Espírito Santo. The variables evaluated included sex, age, breed, municipality of origin, anatomical location and diagnostic method. Most cases originated from Colatina (77.7%), and the majority of affected dogs were female (63.4%) with a mean age of 8.8 y. Mixed-breed dogs were the most frequently affected (37.1%), followed by Shih Tzus, Labrador Retrievers, and Poodles. The trunk was the most common anatomical site of disease (61.1%). Clinically, most lipomas are asymptomatic; however, large masses occasionally lead to locomotor difficulty, compression of adjacent structures, or decreased quality of life. Macroscopically, the lesions measured 0.5–20.0 cm, were soft and white, and exhibited a greasy cut surface. Cytological evaluation revealed low-cellularity smears predominantly composed of mature adipocytes with large clear vacuoles, peripherally displaced nuclei, and minimal pleomorphism. Histopathological examination revealed well-circumscribed neoplasms composed of mature adipocytes arranged in indistinct lobules, displaying anisocytosis related to vacuole size, minimal anisokaryosis, and no mitotic figures. In conclusion, lipomas in dogs from Espírito Santo mainly affected adult and elderly females and mixed-breed dogs, with the trunk being the most common site of occurrence. Cytology is a highly valuable diagnostic tool; however, histopathological confirmation remains essential, particularly for atypical presentations. These findings enhance the epidemiological and clinicopathological understanding of canine lipomas in Brazil. Dogs lipoma epidemiology cytology histology retrospective study Figures Figure 1 Figure 2 Figure 3 Introduction Lipomas are the most common benign mesenchymal neoplasms in dogs, characterized by the proliferation of mature adipocytes that grow slowly and expansively, primarily in subcutaneous tissues (Gross et al. 2005 ; Hendrick 2016 ; O’Neill et al. 2018 ). Although typically asymptomatic, large or strategically located lipomas may cause clinical complications that can negatively impact animal welfare, being common indications for surgery (Subapriya et al. 2020 ; Sasikala et al. 2020 ). The prevalence of canine lipomas varies by region and methodology; however, they are more frequently reported in females, older dogs, and in Labrador Retrievers, Shih Tzus, and mixed-breed dogs (O’Neill et al. 2018 ; Subapriya et al. 2020 ; Pegram et al. 2020 ). In Brazil, epidemiological studies are scarce, particularly those integrating both cytological and histopathological diagnostic approaches. Macroscopically, lipomas are well circumscribed, soft and mostly subcutaneous and freely moveable masses (Hendrick 2016 ). Cytological examination is widely used for the initial diagnosis of lipomas because of its speed, low cost, and high sensitivity (Einarsdóttir et al. 2004 ). However, histopathological analysis remains essential for confirming the diagnosis, especially in cases with unusual locations, large or infiltrative masses, and suspected malignancies (Avallone et al. 2017 ; Mcchesney et al. 1980 ). Given the clinical importance and frequency of lipomas in the daily routine of veterinary medicine, studies that characterize their clinical, epidemiological, cytological, and histopathological features are fundamental for supporting the diagnosis, prognosis, and management of affected animals (Pegram et al. 2020 ; Conrado et al. 2019 ). Therefore, this study aimed to characterize the epidemiological, cytological, and histopathological aspects of canine lipomas diagnosed in the central region of Espírito Santo, Brazil. Material and Methods Sample and data collection methods This retrospective observational study included cases of canine lipomas diagnosed between 2018 and 2024 in Espírito Santo, Brazil. Data were collected from fine-needle and excisional biopsies and necropsy records of the Veterinary Pathology Laboratory located in the municipality of Colatina, Espírito Santo Dogs of any breed, sex, or age diagnosed with lipomas through cytological or histopathological examination were included. Patients with duplicate or incomplete data were excluded. Epidemiological and clinical data were collected from the patients The following variables were recorded for each patient: sex, age (years), breed, municipality of origin, anatomical location of the mass, and diagnostic method (cytological and/or histopathological). Cytological evaluation Fine-needle aspiration (FNA) was performed on palpable masses after antisepsis of the area using 21- or 22-gauge needles attached to 5 or 10 mL syringes, respectively. The aspirated material was smeared onto glass slides, air-dried, and stained with rapid panoptic or May-Grünwald-Giemsa stains according to routine laboratory protocols. Histopathological Evaluation Samples for histopathology were obtained by excisional or incisional biopsy and fixed in 10% neutral-buffered formalin for at least 24 h. Tissues were processed routinely, embedded in paraffin, sectioned to a thickness of 4–5 µm, and stained with hematoxylin and eosin (HE). Data analysis Descriptive statistical analyses were performed for all variables using Microsoft Excel. Absolute and relative frequencies were calculated for categorical variables, whereas measures of central tendency (mean and median) and dispersion (standard deviation) were calculated for quantitative variables (e.g., age). Ethical considerations This study was based on a retrospective analysis of clinical and laboratory records. No experimental procedures or interventions were performed on the animals. Results This study included 175 cases of canine lipomas diagnosed between 2018 and 2024 in Espírito Santo, Brazil. The majority of cases originated from the municipality of Colatina (77.7%), with additional cases distributed among Vitória, Domingos Martins, Nova Venécia, Baixo Guandu, Itaguaçu, Santa Maria de Jetibá, Santa Teresa, Rio Bananal, and Linhares (Fig. 1 ). Among the affected animals, the majority were female (63.4%), with males accounting for 36% of the cases; sex was not recorded in only one case. Age data were available for 154 patients (88.0%). The ages of the animals ranged from 1 to 17 years, with a mean age of 8.8 years and a median age of 9 years, indicating a predominance of adult and older dogs. Mixed-breed dogs were the most frequently affected (37.1%), followed by Shih-tzu (9,1%), Poodle (6,9%), Labrador Retriever (6,3%), Lhasa Apso (5,1%), Yorkshire Terrier (4,6%), and Beagle (3,4%). Other purebred dogs were less frequently represented in the study. In a small proportion of cases, the breed was not specified. The trunk was the most common site for lipoma development, representing 61.1% of the cases. Masses located on the limbs (thoracic and pelvic) accounted for 7.4% of the cases, whereas the neck and head were less commonly affected (Fig. 2 ). The anatomical location was not specified in 27.4% of the records. Macroscopic evaluation of the lipoma cases revealed a broad morphological spectrum, with lesions measuring 0.5–20.0 cm in their greatest dimension. Most masses presented as expansive subcutaneous nodules with rounded to irregular contours, predominantly soft consistency, homogeneous white coloration, and greasy appearance on the cut surface. In some cases, firmer areas and foci of hemorrhage were observed (Fig. 3 A). Cytology was the primary diagnostic method and was performed in 74.3% of cases, whereas histopathological evaluation was available in 25.7% of cases. In a subset of cases, both cytology and histopathology were performed, with histopathology serving as a confirmatory method. Cytological evaluation of the lipomas revealed smears with low cellularity, predominantly composed of adipocytes organized in groups, and exhibiting a low nucleus-to-cytoplasm ratio. The cytoplasm was abundant and contained large negative vacuoles. The nucleus was round to elongated, compressed, and located at the cell periphery. Cellular and nuclear pleomorphism, anisocytosis, and anisokaryosis were minimal. The background of the slides frequently showed numerous droplets of lipid material (Fig. 3 B) Histopathological analysis revealed a moderately cellular, well-circumscribed, and partially encapsulated neoplasm composed of mature adipocytes arranged in indistinct lobules within a thin fibrovascular stroma. The neoplastic adipocytes displayed distinct cell borders and a single clear (lipid) vacuole measuring 60–130 µm, which compressed and displaced a flattened hyperchromatic nucleus to the cell periphery. Anisocytosis was marked depending on the size of the vacuole, but anisokaryosis was minimal (Fig. 3 C). No mitotic activity was observed in the tumor cells. Discussion The present study retrospectively characterized canine lipomas over six years, predominantly affecting adult and elderly dogs, with higher prevalence in females and mixed breeds. These findings agree with reports identifying age, sex, and overweight as predisposing factors (O’Neill et al. 2018 ; Subapriya et al. 2020 ; Sasikala et al. 2020 ; Pegram et al. 2020 ). The mean age (8.8 years) supports their occurrence mainly in mature and geriatric dogs (Gross et al. 2005 ; Hendrick 2016 ; O’Neill et al. 2018 ; Subapriya et al. 2020 ). Systematic palpation of subcutaneous tissues, especially in overweight dogs, is recommended for early detection and management. However, the absence of body condition data limited the assessment of its association with lipoma development. The predominance of mixed-breed dogs, followed by Shih Tzus, Labrador Retrievers, and Poodles, agrees with reports highlighting high frequencies in crossbred animals and breed predispositions (O’Neill et al. 2018 ; Pegram et al. 2020 ). Although inconsistently reported, the higher occurrence in females may be related to hormonal and metabolic factors (Subapriya et al. 2020 ; Sasikala et al. 2020 ). Thus, assessing reproductive status during anamnesis is recommended, as hormonal influences and neutering may affect tumor development. Regarding the anatomical location, the trunk was the most frequently affected site (Hendrick 2016 ; Subapriya et al. 2020 ). The predilection for the trunk and proximal limbs is likely related to the greater abundance of subcutaneous adipose tissue in these areas. Lipomas in the cervical, axillary, or inguinal areas may lead to functional impairment or compression. In such cases, surgical removal should be considered to preserve the animal’s quality of life. In this study, cytology was the main diagnostic method, reflecting its accuracy and widespread use in small-animal practice. Typical findings included low-cellularity smears composed of grouped or isolated mature adipocytes with abundant cytoplasm, large clear vacuoles, peripherally displaced nuclei, minimal pleomorphism, and lipid-rich background. These features are consistent with the established cytological profile of lipomas described in the literature (Subapriya et al. 2020 ; Einarsdóttir et al. 2004 ; Raskin and Conrado 2023). Despite its usefulness, cytology alone may not reliably distinguish all variants, such as infiltrative lipomas or early stage liposarcomas, which require histopathological confirmation (Gross et al. 2005 ; Hendrick 2016 ; Avallone et al. 2017 ; Mcchesney et al. 1980 ). A key cytopathological differential diagnosis is normal subcutaneous fat, which may appear similar on smears but lacks the clinical context and organization typical of neoplastic processes. In the present study, this differentiation was based on the integration of cytological findings with clinical information obtained from the medical records, including lesion localization, growth pattern, clinically interpreted as nodular or mass-forming processes and macroscopic description when available. A relevant observation in this study is that, following a cytological diagnosis suggestive of lipoma, many clinicians proceed with surgical excision without histopathological confirmation. Although often justified by the typically benign nature of lipomas and practical or financial considerations, this approach carries the risk of overlooking rare variants or malignant tumors that may mimic lipomas cytologically. In this context, the role of the general practitioner is essential, both in accurate clinical evaluation and in effective communication with pet owners. The routine submission of excised masses for histopathological examination should therefore be encouraged as standard practice to ensure early diagnosis and appropriate clinical decision-making. Histopathological evaluation in this study consistently revealed well-circumscribed, partially encapsulated neoplasms composed of mature adipocytes arranged in indistinct lobules, with a single clear vacuole compressing the nucleus at the periphery of the vacuole. These features are classical and reinforce the reliability of histopathology for definitive diagnoses (Gross et al. 2005 ; Hendrick 2016 ). Mitoses are not observed, and anisocytosis, when present, is correlated with vacuole size rather than malignant transformation (Gross et al. 2005 ; Hendrick 2016 ). Geographically, the concentration of cases in the municipality of Colatina is likely explained by the presence of the diagnostic laboratory at this location, which facilitates sample submission and case referrals from local clinics and neighboring regions. Similar findings have been reported in other regional studies, where the proximity of diagnostic centers significantly influenced case distribution (Subapriya et al. 2020 ). This finding highlights the importance of accessible complementary diagnostic services in ensuring accurate diagnosis, guiding clinical decisions, and improving patient outcomes. The limitations of the present study include its retrospective design and incomplete information for some variables, especially regarding the anatomical location or signalment in a subset of records. Nevertheless, the large sample size and integration of cytological and histopathological data add robustness to our findings. In conclusion, this study reinforces the notion that lipomas are common in dogs, especially among elderly females and mixed-breed animals, and that the trunk is the most frequently affected site of the body. Although cytology is a highly effective and accessible diagnostic tool, histopathological analysis of all excised masses should be encouraged to rule out unusual variants and ensure optimal care. These data contribute to the epidemiological and clinical understanding of lipomas in Espírito Santo and may support future improvements in the diagnostic and management strategies for canine soft tissue tumors. Declarations Conflict of interest statement The authors declare no conflicts of interest. Author Contribution E.P. Andrade, L. Martinelli, A.T. Soares, H.H.R. Gregorio, L.F. Vieira, V.Z. Lemos, T.S. Alberti, E.S.V. Sallis, H.V. Scheid, F.C.A.Q. Castro, J.M, Cota, and C. Marcolongo-Pereira: All authors contributed equally to the study conception and design, data curation, formal analysis, investigation, and methodology, as well as to the drafting, critical revision, and final approval of the manuscript. Acknowledgments Data Availability The datasets generated and analyzed during the current study are not publicly available due to patient confidentiality and institutional policies but may be made available from the corresponding author upon reasonable request. References Avallone G, Pellegrino V, Muscatello LV, Sarli G, Roccabianca P (2017) Spindle Cell Lipoma in Dogs. Vet Pathol 54:792–794. https://doi.org/10.1177/0300985817707022 Conrado FO, Spoldi E, Kieran EA, Dark MJ, Leissinger MK (2019) Fine-needle aspirate of a large mass in the ventral peritoneal space of a dog. Vet Clin Pathol 48:355–357. https://doi.org/10.1111/vcp.12716 Einarsdóttir H, Skoog L, Söderlund V, Bauer HCF (2004) Accuracy of cytology for diagnosis of lipomatous tumors: comparison with magnetic resonance and computed tomography findings in 175 cases. Acta Radiol 45:840–846. https://doi.org/10.1080/02841850410008180 Gross TL, Ihrke PJ, Walder EJ, Affolter VK (2005) Skin Diseases of the Dog and Cat: Clinical and Histopathologic Diagnosis, 2nd edn. Blackwell Science Ltd, Oxford, UK Hendrick MJ (2016) Mesenchymal Tumors of the Skin and Soft Tissues. Tumors in Domestic Animals. Wiley, pp 142–175. https://doi.org/10.1002/9781119181200.ch5 Mcchesney AE, Stephens LC, Lebel J, Snyder S, Ferguson HR (1980) Infiltrative Lipoma in Dogs. Vet Pathol 17:316–322. https://doi.org/10.1177/030098588001700305 O’Neill DG, Corah CH, Church DB, Brodbelt DC, Rutherford L (2018) Lipoma in dogs under primary veterinary care in the UK: prevalence and breed associations. Canine Genet Epidemiol 5:9. https://doi.org/10.1186/s40575-018-0065-9 Pegram CL, Rutherford L, Corah C, Church DB, Brodbelt DC, O’Neill DG (2020) Clinical management of lipomas in dogs under primary care in the UK. Vet Rec 187:e83–e83. https://doi.org/10.1136/vr.105804 Raskin RE, Conrado FO. Integumentary system. Canine and, Cytopathology F (2023) Elsevier; pp. 35–123. https://doi.org/10.1016/B978-0-323-68368-5.00012-8 Sasikala M, Arulmozhi A, Balasubramaniam GA, Kathirvel S, Vigneshwaran S (2020) Pathology of Giant Lipoma in a Non-descript Dog: A Case Report. J Entomol Zool Stud 8:1531–1533 Subapriya S, Vairamuthu S, Pazhanivel N, George RS, Gokulakrishnan M (2020) Cutaneous lipoma in dogs. J Entomol Zool Stud 8:17–19 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviewers invited by journal 16 Apr, 2026 Editor assigned by journal 16 Apr, 2026 Submission checks completed at journal 16 Apr, 2026 First submitted to journal 06 Apr, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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17:08:30","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9336078/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9336078/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":107832758,"identity":"911b5355-a467-46e6-b1d6-821c84e4c841","added_by":"auto","created_at":"2026-04-26 15:36:11","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":156911,"visible":true,"origin":"","legend":"\u003cp\u003eDistribution of canine lipomas diagnosed between 2018 and 2024 in the state of Espírito Santo, Brazil.\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-9336078/v1/4c4f80d0c654022c785abdba.jpeg"},{"id":107869399,"identity":"51da4e02-30f1-4025-a71d-4480b8f2d966","added_by":"auto","created_at":"2026-04-27 07:36:58","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":57070,"visible":true,"origin":"","legend":"\u003cp\u003eAnatomical distribution of lipomas in dogs. Predominance of lipomas in the trunk, followed by the thoracic and pelvic limbs, with the neck and head being less commonly affected by lipomas.\u003c/p\u003e","description":"","filename":"floatimage2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-9336078/v1/d432142299011c0cf8801277.jpeg"},{"id":107832760,"identity":"9410adb7-6018-4308-9b28-cd07d5c876dc","added_by":"auto","created_at":"2026-04-26 15:36:11","extension":"jpeg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":579129,"visible":true,"origin":"","legend":"\u003cp\u003eA) Macroscopic characteristics of lipomas in dogs. Expansive nodules, presenting contours that varied from rounded to irregular, soft, homogeneous white, and greasy, with cut surfaces. B) Cytological evaluation of a lipoma showing low cellularity smears dominated by grouped adipocytes, exhibiting a low nucleus-to-cytoplasm ratio, ample cytoplasm with a large-negative vacuole, and a peripherally compressed nucleus. Minimal cellular and nuclear pleomorphism, anisocytosis, and anisokaryosis were also observed. Romanowsky stain, bar = 50µm. C) Histopathological section of a lipoma, showing mature adipocytes organized in indistinct lobules within a thin fibrovascular stroma. Note the prominent clear lipid vacuoles compressing and displacing the flattened hyperchromatic nuclei to the cell periphery. Marked anisocytosis and minimal anisokaryosis were observed, with no evidence of mitotic figures. H\u0026amp;E, bar = 50µm.\u003c/p\u003e","description":"","filename":"floatimage3.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-9336078/v1/e6bef608a6f74b90f9a1ed63.jpeg"},{"id":107871762,"identity":"f823c74b-2f89-44ea-b49e-4ca1a8ec0e4a","added_by":"auto","created_at":"2026-04-27 07:54:06","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":941295,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9336078/v1/0313d75e-823a-40ef-9052-1385b278a615.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Clinical, cytological, and histopathological features of canine lipomas: a retrospective study in Espírito Santo, Brazil","fulltext":[{"header":"Introduction","content":"\u003cp\u003eLipomas are the most common benign mesenchymal neoplasms in dogs, characterized by the proliferation of mature adipocytes that grow slowly and expansively, primarily in subcutaneous tissues (Gross et al. \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2005\u003c/span\u003e; Hendrick \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; O\u0026rsquo;Neill et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Although typically asymptomatic, large or strategically located lipomas may cause clinical complications that can negatively impact animal welfare, being common indications for surgery (Subapriya et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2020\u003c/span\u003e; Sasikala et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2020\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe prevalence of canine lipomas varies by region and methodology; however, they are more frequently reported in females, older dogs, and in Labrador Retrievers, Shih Tzus, and mixed-breed dogs (O\u0026rsquo;Neill et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2018\u003c/span\u003e; Subapriya et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2020\u003c/span\u003e; Pegram et al. \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). In Brazil, epidemiological studies are scarce, particularly those integrating both cytological and histopathological diagnostic approaches.\u003c/p\u003e \u003cp\u003eMacroscopically, lipomas are well circumscribed, soft and mostly subcutaneous and freely moveable masses (Hendrick \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). Cytological examination is widely used for the initial diagnosis of lipomas because of its speed, low cost, and high sensitivity (Einarsd\u0026oacute;ttir et al. \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2004\u003c/span\u003e). However, histopathological analysis remains essential for confirming the diagnosis, especially in cases with unusual locations, large or infiltrative masses, and suspected malignancies (Avallone et al. \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Mcchesney et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1980\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eGiven the clinical importance and frequency of lipomas in the daily routine of veterinary medicine, studies that characterize their clinical, epidemiological, cytological, and histopathological features are fundamental for supporting the diagnosis, prognosis, and management of affected animals (Pegram et al. \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2020\u003c/span\u003e; Conrado et al. \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2019\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eTherefore, this study aimed to characterize the epidemiological, cytological, and histopathological aspects of canine lipomas diagnosed in the central region of Esp\u0026iacute;rito Santo, Brazil.\u003c/p\u003e"},{"header":"Material and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eSample and data collection methods\u003c/h2\u003e \u003cp\u003eThis retrospective observational study included cases of canine lipomas diagnosed between 2018 and 2024 in Esp\u0026iacute;rito Santo, Brazil. Data were collected from fine-needle and excisional biopsies and necropsy records of the Veterinary Pathology Laboratory located in the municipality of Colatina, Esp\u0026iacute;rito Santo\u003c/p\u003e \u003cp\u003eDogs of any breed, sex, or age diagnosed with lipomas through cytological or histopathological examination were included. Patients with duplicate or incomplete data were excluded.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eEpidemiological and clinical data were collected from the patients\u003c/h3\u003e\n\u003cp\u003eThe following variables were recorded for each patient: sex, age (years), breed, municipality of origin, anatomical location of the mass, and diagnostic method (cytological and/or histopathological).\u003c/p\u003e\n\u003ch3\u003eCytological evaluation\u003c/h3\u003e\n\u003cp\u003eFine-needle aspiration (FNA) was performed on palpable masses after antisepsis of the area using 21- or 22-gauge needles attached to 5 or 10 mL syringes, respectively. The aspirated material was smeared onto glass slides, air-dried, and stained with rapid panoptic or May-Gr\u0026uuml;nwald-Giemsa stains according to routine laboratory protocols.\u003c/p\u003e\n\u003ch3\u003eHistopathological Evaluation\u003c/h3\u003e\n\u003cp\u003eSamples for histopathology were obtained by excisional or incisional biopsy and fixed in 10% neutral-buffered formalin for at least 24 h. Tissues were processed routinely, embedded in paraffin, sectioned to a thickness of 4\u0026ndash;5 \u0026micro;m, and stained with hematoxylin and eosin (HE).\u003c/p\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eData analysis\u003c/h2\u003e \u003cp\u003eDescriptive statistical analyses were performed for all variables using Microsoft Excel. Absolute and relative frequencies were calculated for categorical variables, whereas measures of central tendency (mean and median) and dispersion (standard deviation) were calculated for quantitative variables (e.g., age).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eEthical considerations\u003c/h2\u003e \u003cp\u003eThis study was based on a retrospective analysis of clinical and laboratory records. No experimental procedures or interventions were performed on the animals.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eThis study included 175 cases of canine lipomas diagnosed between 2018 and 2024 in Esp\u0026iacute;rito Santo, Brazil. The majority of cases originated from the municipality of Colatina (77.7%), with additional cases distributed among Vit\u0026oacute;ria, Domingos Martins, Nova Ven\u0026eacute;cia, Baixo Guandu, Itagua\u0026ccedil;u, Santa Maria de Jetib\u0026aacute;, Santa Teresa, Rio Bananal, and Linhares (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eAmong the affected animals, the majority were female (63.4%), with males accounting for 36% of the cases; sex was not recorded in only one case. Age data were available for 154 patients (88.0%). The ages of the animals ranged from 1 to 17 years, with a mean age of 8.8 years and a median age of 9 years, indicating a predominance of adult and older dogs.\u003c/p\u003e \u003cp\u003eMixed-breed dogs were the most frequently affected (37.1%), followed by Shih-tzu (9,1%), Poodle (6,9%), Labrador Retriever (6,3%), Lhasa Apso (5,1%), Yorkshire Terrier (4,6%), and Beagle (3,4%). Other purebred dogs were less frequently represented in the study. In a small proportion of cases, the breed was not specified.\u003c/p\u003e \u003cp\u003eThe trunk was the most common site for lipoma development, representing 61.1% of the cases. Masses located on the limbs (thoracic and pelvic) accounted for 7.4% of the cases, whereas the neck and head were less commonly affected (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The anatomical location was not specified in 27.4% of the records.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eMacroscopic evaluation of the lipoma cases revealed a broad morphological spectrum, with lesions measuring 0.5\u0026ndash;20.0 cm in their greatest dimension. Most masses presented as expansive subcutaneous nodules with rounded to irregular contours, predominantly soft consistency, homogeneous white coloration, and greasy appearance on the cut surface. In some cases, firmer areas and foci of hemorrhage were observed (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eA).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eCytology was the primary diagnostic method and was performed in 74.3% of cases, whereas histopathological evaluation was available in 25.7% of cases. In a subset of cases, both cytology and histopathology were performed, with histopathology serving as a confirmatory method.\u003c/p\u003e \u003cp\u003eCytological evaluation of the lipomas revealed smears with low cellularity, predominantly composed of adipocytes organized in groups, and exhibiting a low nucleus-to-cytoplasm ratio. The cytoplasm was abundant and contained large negative vacuoles. The nucleus was round to elongated, compressed, and located at the cell periphery. Cellular and nuclear pleomorphism, anisocytosis, and anisokaryosis were minimal. The background of the slides frequently showed numerous droplets of lipid material (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eB)\u003c/p\u003e \u003cp\u003eHistopathological analysis revealed a moderately cellular, well-circumscribed, and partially encapsulated neoplasm composed of mature adipocytes arranged in indistinct lobules within a thin fibrovascular stroma. The neoplastic adipocytes displayed distinct cell borders and a single clear (lipid) vacuole measuring 60\u0026ndash;130 \u0026micro;m, which compressed and displaced a flattened hyperchromatic nucleus to the cell periphery. Anisocytosis was marked depending on the size of the vacuole, but anisokaryosis was minimal (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eC). No mitotic activity was observed in the tumor cells.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe present study retrospectively characterized canine lipomas over six years, predominantly affecting adult and elderly dogs, with higher prevalence in females and mixed breeds. These findings agree with reports identifying age, sex, and overweight as predisposing factors (O\u0026rsquo;Neill et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2018\u003c/span\u003e; Subapriya et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2020\u003c/span\u003e; Sasikala et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2020\u003c/span\u003e; Pegram et al. \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). The mean age (8.8 years) supports their occurrence mainly in mature and geriatric dogs (Gross et al. \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2005\u003c/span\u003e; Hendrick \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; O\u0026rsquo;Neill et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2018\u003c/span\u003e; Subapriya et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Systematic palpation of subcutaneous tissues, especially in overweight dogs, is recommended for early detection and management. However, the absence of body condition data limited the assessment of its association with lipoma development.\u003c/p\u003e \u003cp\u003eThe predominance of mixed-breed dogs, followed by Shih Tzus, Labrador Retrievers, and Poodles, agrees with reports highlighting high frequencies in crossbred animals and breed predispositions (O\u0026rsquo;Neill et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2018\u003c/span\u003e; Pegram et al. \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Although inconsistently reported, the higher occurrence in females may be related to hormonal and metabolic factors (Subapriya et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2020\u003c/span\u003e; Sasikala et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Thus, assessing reproductive status during anamnesis is recommended, as hormonal influences and neutering may affect tumor development.\u003c/p\u003e \u003cp\u003eRegarding the anatomical location, the trunk was the most frequently affected site (Hendrick \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Subapriya et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). The predilection for the trunk and proximal limbs is likely related to the greater abundance of subcutaneous adipose tissue in these areas. Lipomas in the cervical, axillary, or inguinal areas may lead to functional impairment or compression. In such cases, surgical removal should be considered to preserve the animal\u0026rsquo;s quality of life.\u003c/p\u003e \u003cp\u003eIn this study, cytology was the main diagnostic method, reflecting its accuracy and widespread use in small-animal practice. Typical findings included low-cellularity smears composed of grouped or isolated mature adipocytes with abundant cytoplasm, large clear vacuoles, peripherally displaced nuclei, minimal pleomorphism, and lipid-rich background. These features are consistent with the established cytological profile of lipomas described in the literature (Subapriya et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2020\u003c/span\u003e; Einarsd\u0026oacute;ttir et al. \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2004\u003c/span\u003e; Raskin and Conrado 2023). Despite its usefulness, cytology alone may not reliably distinguish all variants, such as infiltrative lipomas or early stage liposarcomas, which require histopathological confirmation (Gross et al. \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2005\u003c/span\u003e; Hendrick \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Avallone et al. \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Mcchesney et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1980\u003c/span\u003e). A key cytopathological differential diagnosis is normal subcutaneous fat, which may appear similar on smears but lacks the clinical context and organization typical of neoplastic processes. In the present study, this differentiation was based on the integration of cytological findings with clinical information obtained from the medical records, including lesion localization, growth pattern, clinically interpreted as nodular or mass-forming processes and macroscopic description when available.\u003c/p\u003e \u003cp\u003eA relevant observation in this study is that, following a cytological diagnosis suggestive of lipoma, many clinicians proceed with surgical excision without histopathological confirmation. Although often justified by the typically benign nature of lipomas and practical or financial considerations, this approach carries the risk of overlooking rare variants or malignant tumors that may mimic lipomas cytologically. In this context, the role of the general practitioner is essential, both in accurate clinical evaluation and in effective communication with pet owners. The routine submission of excised masses for histopathological examination should therefore be encouraged as standard practice to ensure early diagnosis and appropriate clinical decision-making.\u003c/p\u003e \u003cp\u003eHistopathological evaluation in this study consistently revealed well-circumscribed, partially encapsulated neoplasms composed of mature adipocytes arranged in indistinct lobules, with a single clear vacuole compressing the nucleus at the periphery of the vacuole. These features are classical and reinforce the reliability of histopathology for definitive diagnoses (Gross et al. \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2005\u003c/span\u003e; Hendrick \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). Mitoses are not observed, and anisocytosis, when present, is correlated with vacuole size rather than malignant transformation (Gross et al. \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2005\u003c/span\u003e; Hendrick \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2016\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eGeographically, the concentration of cases in the municipality of Colatina is likely explained by the presence of the diagnostic laboratory at this location, which facilitates sample submission and case referrals from local clinics and neighboring regions. Similar findings have been reported in other regional studies, where the proximity of diagnostic centers significantly influenced case distribution (Subapriya et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). This finding highlights the importance of accessible complementary diagnostic services in ensuring accurate diagnosis, guiding clinical decisions, and improving patient outcomes.\u003c/p\u003e \u003cp\u003eThe limitations of the present study include its retrospective design and incomplete information for some variables, especially regarding the anatomical location or signalment in a subset of records. Nevertheless, the large sample size and integration of cytological and histopathological data add robustness to our findings.\u003c/p\u003e \u003cp\u003eIn conclusion, this study reinforces the notion that lipomas are common in dogs, especially among elderly females and mixed-breed animals, and that the trunk is the most frequently affected site of the body. Although cytology is a highly effective and accessible diagnostic tool, histopathological analysis of all excised masses should be encouraged to rule out unusual variants and ensure optimal care. These data contribute to the epidemiological and clinical understanding of lipomas in Esp\u0026iacute;rito Santo and may support future improvements in the diagnostic and management strategies for canine soft tissue tumors.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003ch2\u003eConflict of interest statement\u003c/h2\u003e \u003cp\u003eThe authors declare no conflicts of interest.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eE.P. Andrade, L. Martinelli, A.T. Soares, H.H.R. Gregorio, L.F. Vieira, V.Z. Lemos, T.S. Alberti, E.S.V. Sallis, H.V. Scheid, F.C.A.Q. Castro, J.M, Cota, and C. Marcolongo-Pereira: All authors contributed equally to the study conception and design, data curation, formal analysis, investigation, and methodology, as well as to the drafting, critical revision, and final approval of the manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgments\u003c/h2\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe datasets generated and analyzed during the current study are not publicly available due to patient confidentiality and institutional policies but may be made available from the corresponding author upon reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAvallone G, Pellegrino V, Muscatello LV, Sarli G, Roccabianca P (2017) Spindle Cell Lipoma in Dogs. Vet Pathol 54:792\u0026ndash;794. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1177/0300985817707022\u003c/span\u003e\u003cspan address=\"10.1177/0300985817707022\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eConrado FO, Spoldi E, Kieran EA, Dark MJ, Leissinger MK (2019) Fine-needle aspirate of a large mass in the ventral peritoneal space of a dog. Vet Clin Pathol 48:355\u0026ndash;357. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1111/vcp.12716\u003c/span\u003e\u003cspan address=\"10.1111/vcp.12716\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEinarsd\u0026oacute;ttir H, Skoog L, S\u0026ouml;derlund V, Bauer HCF (2004) Accuracy of cytology for diagnosis of lipomatous tumors: comparison with magnetic resonance and computed tomography findings in 175 cases. Acta Radiol 45:840\u0026ndash;846. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1080/02841850410008180\u003c/span\u003e\u003cspan address=\"10.1080/02841850410008180\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGross TL, Ihrke PJ, Walder EJ, Affolter VK (2005) Skin Diseases of the Dog and Cat: Clinical and Histopathologic Diagnosis, 2nd edn. Blackwell Science Ltd, Oxford, UK\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHendrick MJ (2016) Mesenchymal Tumors of the Skin and Soft Tissues. Tumors in Domestic Animals. Wiley, pp 142\u0026ndash;175. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1002/9781119181200.ch5\u003c/span\u003e\u003cspan address=\"10.1002/9781119181200.ch5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMcchesney AE, Stephens LC, Lebel J, Snyder S, Ferguson HR (1980) Infiltrative Lipoma in Dogs. Vet Pathol 17:316\u0026ndash;322. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1177/030098588001700305\u003c/span\u003e\u003cspan address=\"10.1177/030098588001700305\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eO\u0026rsquo;Neill DG, Corah CH, Church DB, Brodbelt DC, Rutherford L (2018) Lipoma in dogs under primary veterinary care in the UK: prevalence and breed associations. Canine Genet Epidemiol 5:9. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1186/s40575-018-0065-9\u003c/span\u003e\u003cspan address=\"10.1186/s40575-018-0065-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePegram CL, Rutherford L, Corah C, Church DB, Brodbelt DC, O\u0026rsquo;Neill DG (2020) Clinical management of lipomas in dogs under primary care in the UK. Vet Rec 187:e83\u0026ndash;e83. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1136/vr.105804\u003c/span\u003e\u003cspan address=\"10.1136/vr.105804\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRaskin RE, Conrado FO. Integumentary system. Canine and, Cytopathology F (2023) Elsevier; pp. 35\u0026ndash;123. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/B978-0-323-68368-5.00012-8\u003c/span\u003e\u003cspan address=\"10.1016/B978-0-323-68368-5.00012-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSasikala M, Arulmozhi A, Balasubramaniam GA, Kathirvel S, Vigneshwaran S (2020) Pathology of Giant Lipoma in a Non-descript Dog: A Case Report. J Entomol Zool Stud 8:1531\u0026ndash;1533\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSubapriya S, Vairamuthu S, Pazhanivel N, George RS, Gokulakrishnan M (2020) Cutaneous lipoma in dogs. J Entomol Zool Stud 8:17\u0026ndash;19\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"veterinary-research-communications","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"verc","sideBox":"Learn more about [Veterinary Research Communications](https://www.springer.com/journal/11259)","snPcode":"11259","submissionUrl":"https://submission.nature.com/new-submission/11259/3","title":"Veterinary Research Communications","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Dogs, lipoma, epidemiology, cytology, histology, retrospective study","lastPublishedDoi":"10.21203/rs.3.rs-9336078/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9336078/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis study aimed to characterize the epidemiological, cytological, and histopathological aspects of canine lipomas diagnosed in Esp\u0026iacute;rito Santo, Brazil. A retrospective analysis was conducted on 175 canine lipoma cases diagnosed between 2018 and 2024 at the Veterinary Pathology Laboratory in Esp\u0026iacute;rito Santo. The variables evaluated included sex, age, breed, municipality of origin, anatomical location and diagnostic method. Most cases originated from Colatina (77.7%), and the majority of affected dogs were female (63.4%) with a mean age of 8.8 y. Mixed-breed dogs were the most frequently affected (37.1%), followed by Shih Tzus, Labrador Retrievers, and Poodles. The trunk was the most common anatomical site of disease (61.1%). Clinically, most lipomas are asymptomatic; however, large masses occasionally lead to locomotor difficulty, compression of adjacent structures, or decreased quality of life. Macroscopically, the lesions measured 0.5\u0026ndash;20.0 cm, were soft and white, and exhibited a greasy cut surface. Cytological evaluation revealed low-cellularity smears predominantly composed of mature adipocytes with large clear vacuoles, peripherally displaced nuclei, and minimal pleomorphism. Histopathological examination revealed well-circumscribed neoplasms composed of mature adipocytes arranged in indistinct lobules, displaying anisocytosis related to vacuole size, minimal anisokaryosis, and no mitotic figures. In conclusion, lipomas in dogs from Esp\u0026iacute;rito Santo mainly affected adult and elderly females and mixed-breed dogs, with the trunk being the most common site of occurrence. Cytology is a highly valuable diagnostic tool; however, histopathological confirmation remains essential, particularly for atypical presentations. These findings enhance the epidemiological and clinicopathological understanding of canine lipomas in Brazil.\u003c/p\u003e","manuscriptTitle":"Clinical, cytological, and histopathological features of canine lipomas: a retrospective study in Espírito Santo, Brazil","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-26 15:36:07","doi":"10.21203/rs.3.rs-9336078/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewersInvited","content":"","date":"2026-04-16T11:26:13+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-04-16T10:39:58+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-04-16T10:39:43+00:00","index":"","fulltext":""},{"type":"submitted","content":"Veterinary Research Communications","date":"2026-04-06T16:56:39+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"veterinary-research-communications","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"verc","sideBox":"Learn more about [Veterinary Research Communications](https://www.springer.com/journal/11259)","snPcode":"11259","submissionUrl":"https://submission.nature.com/new-submission/11259/3","title":"Veterinary Research Communications","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"fce51e53-b74e-4d6a-b193-0c6ff7d5446b","owner":[],"postedDate":"April 26th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-26T15:36:07+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-26 15:36:07","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9336078","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9336078","identity":"rs-9336078","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}