Huge angioleiomyoma of the uterus, suspected to be an ovarian tumor: a case report

Background Angioleiomyoma of the uterus is an extremely rare benign tumor and a variant of uterine leiomyoma. In this study, a case of uterine angioleiomyoma was initially mistaken for an ovarian tumor. However, it was successfully surgically managed, and histology revealed the pathology. Case report A 33-year-old Nigerian female patient, nullipara with phocomelia, presented with a complaint of abdominal discomfort of 15 years and abdominal swelling of 5-year duration. The abdomen was distended on examination to about 40 weeks’ size. Abdominopelvic ultrasound and computed tomography scans suspected right ovarian malignancy. Cancer antigen 125 was elevated at 189U/mL (normal < 35U/mL). She had a laparotomy for suspected ovarian malignancy with excision of the abdominal mass. Intraoperative findings were ascitic fluid of 15 L and a huge cystic multi-septate mass measuring 30 cm × 26 cm, which weighed 6 kg and was attached to the fundus of the uterus by a stalk. Hysterectomy was not carried out because she was nullipara, and the uterus with its appendages appeared normal. Histopathology revealed uterine angioleiomyoma. Her postoperative recovery was satisfactory, and there has been no recurrence of symptoms. Uterine angioleiomyoma is a rare benign tumor, originating from the mesenchymal tissue and composed of smooth muscle cells and thick-walled vessels of the uterus. The diagnosis of uterine angioleiomyoma is not always possible, as large‑sized lesions may predominantly mask other pelvic structures and make it difficult to visualize the ovaries, thereby mimicking an ovarian tumor, as seen in our case. The choice of treatment is surgical excision of the mass, which was done for this patient.

Although uterine angioleiomyoma is rare, it should be suspected if radiological investigation reveals a multilobulated mass with solid, cystic, and multi-septal content in middle-aged women. The good outcome further strengthens the role of proper surgical care and follow-up histology in patients with symptomatic gynecological abdominal tumors. Similar content being viewed by others

Angioleiomyoma, otherwise known as vascular leiomyoma, is a rare and distinctive variant of leiomyoma that arises from smooth muscle cells and is characterized by the presence of prominent thick-walled blood vessels within the tumor mass [1]. This uncommon tumor is predominantly found in the lower extremities, particularly in the subcutaneous tissues of the legs, and occurs more frequently in middle-aged women [2]. The occurrence of angioleiomyoma in other anatomical sites is rare, making its detection in locations such as the uterus highly unusual and clinically significant. Uterine angioleiomyoma is usually considered a benign mesenchymal tumor [2, 3]. Despite its benign nature, uterine angioleiomyoma can mimic other gynecological pathologies both clinically and radiologically, which poses a considerable diagnostic challenge [2, 3]. The imaging characteristics of angioleiomyoma often overlap with those of more common uterine tumors, such as conventional leiomyomas or even malignant neoplasms. As a result, diagnosis is rarely established through imaging studies alone [2]. In most cases, conclusive diagnosis can only be made following a thorough histopathological examination of the excised specimen, underscoring the importance of tissue diagnosis in such cases. In this report, we describe a rare and noteworthy case of a giant uterine angioleiomyoma detected in a 33-year-old woman who presented to our facility with complaints of persistent abdominal discomfort and a gradually enlarging abdominal mass that had become visibly distended. The clinical presentation was nonspecific, and initial evaluation raised suspicions of a possible pelvic mass of unknown etiology. As part of the diagnostic workup, we performed an abdominopelvic ultrasound scan and a computed tomography (CT) scan, which revealed a large pelvic–abdominal mass. In addition, we measured serum cancer antigen 125 (CA-125) levels to assist in the differentiation between benign and malignant etiologies. We focus our discussion on the radiological findings, including ultrasound and CT imaging features, as well as the role of serum tumor markers such as CA-125 in preoperative evaluation. However, despite these investigative efforts, the diagnosis of uterine angioleiomyoma was not established until the final histology report was obtained following surgical excision of the mass. This underscores the inherent limitations of imaging and tumor markers in detecting this rare tumor and emphasizes the pivotal role of histopathological examination in achieving a definitive diagnosis. This case, which was successfully managed in our institution, serves to contribute to the limited literature on uterine angioleiomyoma and provides insight into the diagnostic dilemmas and therapeutic strategies associated with this rare clinical entity. Our experience highlights the importance of maintaining a high index of suspicion and adopting a multidisciplinary approach involving gynecologists, radiologists, general surgeons, and pathologists in the accurate diagnosis and optimal management of such cases. Case report A 33-year-old Nigerian female patient, nullipara with phocomelia, presented in our gynecology outpatient clinic with complaints of abdominal discomfort of 15-year duration and abdominal swelling of 5-year duration. The abdominal swelling was insidious in onset and progressively increased in size. There was no abdominal pain or change in bowel habit. She had initially presented at the surgery outpatient clinic where she was seen and reviewed by general surgeons who noted a huge intra-abdominopelvic mass for which radiological investigation where requested. Ultrasound scan revealed gross ascites with perpendicular height of about 26.9 mm in Morrison’s pouch, suggestive of greater than 2.7 L of intraperitoneal fluid extending to the pelvis and involving the pouch of Douglas. There was a large, thick-walled, multi-septated cystic mass lesion with solid components appearing to rise from the right adnexa region of the pelvis and extending into the right upper abdomen, measuring in parts approximately 37.8 × 19.4 × 39.2 cm in size with a volume of about 15.0 L, which is equivalent to 15 kg. The cystic part of the lesion contained low-level echogenic debris as well as thick floating internal septations. It showed moderate internal vascularity within its solid component and could not be seen as being separate from the right ovary. The impression was of a large complex intra-abdominal mass appearing to involve the right adnexa with massive ascites. Right ovarian malignancy was a strong consideration. An abdominopelvic CT scan was carried out, which showed a complex mass measuring 16.84 × 27.16 × 33.93 cm containing both solid and cystic components, with the cystic components having septations and solid parts. There were also multiple areas of hypodensities suggestive of fluid content. The mass appeared to arise from the right adnexa into the abdomen with displacement of the bowels, with the conclusion being that it was a complex abdominal mass arising from the right adnexa, suggestive of ovarian cystadenoma or cystadenocarcinoma. CA-125 was elevated at 189U/mL (normal < 35U/mL); other laboratory tests were normal. An impression of suspected ovarian malignancy was made, and she was referred by the general surgeons to the gynecology clinic for further care. Examination findings at presentation in the gynecology clinic revealed a 40-week size grossly distended abdomen (Fig. 1), and abdominal organs could not be palpated due to massive ascites. Ascites was demonstrable by fluid thrill. An impression of a suspected huge ovarian mass was made, and she was scheduled for surgery. The surgery of this patient was carried out with the general surgeons in attendance. She had an exploratory laparotomy with intraoperative findings of filmy adhesions between the mass and anterior abdominal wall as well as serous (straw colored) ascitic fluid in the peritoneum (15 L). There was a huge cystic septate mass measuring 30 cm × 26 cm and weighing 6 kg. The mass consisted of three pockets; one spontaneously ruptured intraoperatively and contained altered blood with necrotic tissues. The mass was attached superiorly to the liver by a fibrous band and inferiorly to the fundus of the uterus by a stalk. The uterus was grossly normal. The ovaries and tubes were grossly normal bilaterally. The mass was separated from the attachments superiorly at the liver with the assistance of the general surgeons and inferiorly by the gynecologist from the fundus of the uterus and delivered through the abdominal incision (Figs. 2). The histology report showed that macroscopically, the specimen consisted of an irregular-shaped, well-circumscribed, and encapsulated mass measuring 25 × 22 × 18 cm. The surface was tan colored and hemorrhagic. Cut sections showed a homogeneous tan-colored solid surface with areas of cystic degeneration containing mucin and clear fluid. Microscopically, sections of the mass showed encapsulated neoplastic proliferation of spindle cells disposed in interlacing fascicles separated by vascularized fibrocollagenous stroma with areas of myxoid changes and hyalinization as well as cystic degeneration. The cells had cigar-shaped, elongated hyperchromic nuclei and scant eosinophilic cytoplasm. Mitosis was rare. Diagnosis was abdominopelvic mass with features in keeping with angioleiomyoma (Fig. 3). Postoperatively, her recovery was satisfactory, the ascites spontaneously resolved, her CA-125 levels normalized, and there has been no recurrence of symptoms (Fig. 4).

Angioleiomyoma of the uterus is an exceptionally rare benign tumor originating from mesenchymal tissue, characterized histologically by a unique combination of smooth muscle cells and thick-walled blood vessels [2, 4]. While angioleiomyomas predominantly arise in the lower extremities, their occurrence in other anatomical regions, such as the uterus, is extremely uncommon [2, 4]. This rarity is reflected in epidemiological data indicating that uterine angioleiomyomas account for only 0.34–0.40% of all uterine leiomyomas [2, 4]. This highlights the unusual nature of the tumor and underscores the importance of documenting such cases to better understand the clinical behaviour and management. Typically, uterine angioleiomyomas are reported in middle-aged female patients [3], but the patient discussed in this case report was a relatively young 33-year-old woman with fertility desires, which influenced the clinical decision-making process and treatment approach. From a histopathological perspective, angioleiomyomas are classified into three distinct variants on the basis of their microscopic architecture: solid (capillary), cavernous, and venous types [2, 4]. In addition to this histological classification, these tumors have also been divided according to their anatomical location into those arising predominantly in the extremities and those found mainly in the head region [5]. Tumors of the extremities are chiefly of the solid variant, whereas those located in the head region tend to be of the venous type [5]. Epidemiological trends demonstrate a gender predilection, with the solid type being three times more prevalent in female individuals, and the cavernous variant appearing four times more frequently in male individuals [5]. In this particular case, the tumor was identified as the solid (capillary) type, which is consistent with its common occurrence in females and its typical predilection for the extremities, although its uterine location remains rare. The exact etiopathogenesis of angioleiomyoma remains poorly understood [2]. However, several theories have been proposed in the literature to explain its development. These include minor trauma leading to vascular proliferation, hamartomatous changes that cause abnormal tissue growth, venous stasis, which might promote vascular engorgement, and hormonal imbalances that could stimulate smooth muscle proliferation [5]. Although these hypotheses offer some insight into potential causative factors, definitive evidence supporting any single mechanism is lacking, indicating the need for further research to elucidate the biological processes behind this tumor’s formation. Clinically, angioleiomyomas present with a range of symptoms, many of which overlap with those of more common uterine pathologies [2,3,4]. The hallmark features include menorrhagia (heavy menstrual bleeding), severe dysmenorrhea (painful menstruation), abdominal pain or discomfort, progressive abdominal swelling, and severe anemia due to chronic uterine bleeding. In the current case, the patient presented with abdominal discomfort, pain, and progressively increasing abdominal swelling that developed insidiously over time, aligning well with the typical symptomatology described in the literature. Beyond these common symptoms, other clinical findings have been reported, such as consumptive coagulopathy—where blood clotting factors are excessively consumed—spontaneous rupture of the tumor causing severe intraabdominal bleeding, pseudo-Meigs syndrome (a rare triad of ascites, pleural effusion, and benign ovarian tumor mimics), and elevated levels of CA-125 (0.2, 6.7). Notably, this patient exhibited an elevated CA-125 level preoperatively, which may raise suspicion for malignancy, and suffered spontaneous cyst rupture intraoperatively, which could have led to acute abdominal complications. One of the significant challenges with uterine angioleiomyomas is the difficulty in establishing a preoperative diagnosis [5]. Due to their rarity and the broad differential diagnoses, including more common uterine and ovarian masses, they are rarely identified before surgical excision and histopathological examination. Large lesions may obscure the visualization of adjacent pelvic structures on imaging, particularly the ovaries, thus mimicking ovarian tumors, as occurred in this case. Hence, angioleiomyoma should be considered when CT scans demonstrate a multilobulated mass arising from the uterus with a characteristic solid and laminated architecture, combined with cystic and multi-septal components [2, 4]. Such radiological features can provide critical diagnostic clues, enabling clinicians to differentiate angioleiomyomas from other pelvic masses and plan appropriate surgical management. Surgical excision remains the mainstay of treatment for uterine angioleiomyomas [5]. In this case, successful removal of the mass was achieved through a collaborative approach involving both a gynecologist and a general surgeon, underscoring the value of multidisciplinary teamwork in managing complex pelvic tumors. Literature reviews consistently indicate that recurrence following complete excision is rare [6,7,8], with a favorable outcome also observed in our patient. While hysterectomy has been the preferred treatment in most reported cases due to the tumor’s vascular nature and potential complications [2, 9], this approach was deliberately avoided here. The patient’s nulliparous status and the intraoperative finding of a normal uterus with intact appendages warranted a fertility-preserving procedure, demonstrating the importance of individualized treatment planning that balances oncologic safety with reproductive goals. This case is a unique presentation of uterine angioleiomyoma in a middle-aged woman with phocomelia, characterized clinically by a huge abdominal swelling and laboratory findings of elevated CA-125. Initially, the tumor was misdiagnosed preoperatively as an ovarian tumor, illustrating the diagnostic challenge posed by this rare entity. However, diligent surgical intervention combined with thorough histopathological examination ultimately confirmed the diagnosis of uterine angioleiomyoma and provided a definitive cure. This case is reported due to its rarity and the diagnostic dilemma it presented, highlighting the critical importance of a multidisciplinary team approach in the effective management of such complex cases. The management timeline was approximately 3 months (Fig. 5).

Uterine angioleiomyoma is a rare benign tumor with distinctive clinical, histological, and radiological features. Its diagnosis poses a challenge preoperatively due to overlapping presentations and imaging findings with other pelvic tumors. Surgical excision remains the cornerstone of management, with fertility-sparing options feasible in select cases. Continued reporting and analysis of such rare tumors are essential to improve understanding and optimize patient outcomes. Data availability Not applicable. Abbreviations - CT: - Computed tomography - CA-125: - Cancer antigen 125

Garg G, Mohanty SK. Uterine angioleiomyoma: a rare variant of uterine leiomyoma. Arch Pathol Lab Med. 2014;138(8):1115–8. Pierro A, Rotondi F, Cilla S, De Ninno M, Mattoni M, Berardi S, et al. Giant angioleiomyoma of uterus: a case report with focus on computed tomography (CT) imaging. Radiol Case Reports. 2018;13(2):371–5. https://doi.org/10.1016/j.radcr.2018.01.015. Hong JA, Heo GE, Kwak JJ, Chung SH. A case report of angioleiomyoma of uterus. Obstet Gynecol Sci. 2017;60(5):494–7. Singh S, Naik M, Bag N, Patra S. Angioleiomyoma of uterus masquerading as malignant ovarian tumor. J Mid-life Health. 2017;8(3):145–7. Taj H, Comba I, Vasquez J, Zayat V. A rare case of angioleiomyoma of the hand. Cureus. 2020;12(4): e7530. https://doi.org/10.7759/cureus.7530. Kim HI, Roh SG, Lee NH, Yang KM, Park HS. Angioleiomyoma of the auricle. Arch Plast Surg. 2013;40(1):68–9. https://doi.org/10.5999/aps.2013.40.1.68. Bodapati VS, Sunderamoorthy D. Angioleiomyoma-rare soft tissue tumor of the foot and ankle, review of two patients and review of the literature. J Surg Case Rep. 2021;2021(12): rjab535. https://doi.org/10.1093/jscr/rjab535. Bernard M, Le Nail L-R, de Pinieux G, Samargandi R. Angioleiomyoma: an update with a 142-case series. Life. 2024;14(3):338. https://doi.org/10.3390/life14030338. Sato H, Murakami K, Fujishima R, Otani T, Sakai K, Nishio K, et al. Uterine angioleiomyoma with disseminated intravascular coagulation: a case report. BMC Womens Health. 2023;23(1):1–6. https://doi.org/10.1186/s12905-023-02292-5.

We appreciate our patient for consenting to this publication. Funding Nil. Author information Authors and Affiliations Contributions The lead author conceptualized this case report, while all authors contributed to the writing of the manuscript and revisions. Corresponding author Ethics declarations Ethics approval and consent to participate Ethical approval is not required by our institution for this case report. A written informed consent was obtained from the patient to participate in this case report. Consent for publication Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal. Competing interests The authors declare that there are no conflicts of interest related to this publication. Additional information Publisher’s Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Rights and permissions Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/. About this article Cite this article Maduako, K.T., Iweka, R.O. & Ehigiegba, O.E. Huge angioleiomyoma of the uterus, suspected to be an ovarian tumor: a case report. J Med Case Reports 20, 248 (2026). https://doi.org/10.1186/s13256-025-05662-9 Received: Accepted: Published: Version of record: DOI: https://doi.org/10.1186/s13256-025-05662-9