{"paper_id":"8011886d-13dc-484e-a50d-09ddb025a266","body_text":"~ 188 ~ \nInternational Journal of Clinical Obstetrics and Gynaecology 2026; 10(1): 188-194 \n \nISSN (P): 2522-6614 \nISSN (E): 2522-6622 \nIndexing: Embase \nImpact Factor (RJIF): 6.71 \n© Gynaecology Journal \nwww.gynaecologyjournal.com \n2026; 10(1): 188-194 \nReceived: 06-08-2025 \nAccepted: 09-09-2025 \n \nDr. Anoushka Gupta \nJunior Resident, Department of Radio \ndiagnosis, SMC, Santosh deemed to be \nUniversity, Ghaziabad, Uttar Pradesh, \nIndia \n \nDr. Ashish Kumar Shukla \nProfessor and HOD, Department of \nRadio diagnosis, SMC, Santosh Deemed \nto be University, Ghaziabad, Uttar \nPradesh, India \n \nDr. Megha Sharma \nConsultant OBG at St. Joseph’s \nHospital, Ghaziabad, Uttar Pradesh, \nIndia \n \nDr. Manvi Dhingra \nJunior Resident, Department of Radio \ndiagnosis, SMC, Santosh deemed to be \nUniversity, Ghaziabad, Uttar Pradesh, \nIndia \n \nDr. Jyoti Yadav  \nJunior Resident, Department of Radio \ndiagnosis, SMC, Santosh deemed to be \nUniversity, Ghaziabad, Uttar Pradesh, \nIndia \n \nDr. Prithvi Chauhan \nJunior Resident, Department of Radio \ndiagnosis, SMC, Santosh deemed to be \nUniversity, Ghaziabad, Uttar Pradesh, \nIndia \n \nDr. Ranjeet Singh \nJunior Resident, Department of Radio \ndiagnosis, SMC, Santosh deemed to be \nUniversity, Ghaziabad, Uttar Pradesh, \nIndia \n \nDr. Shipra Chaudhary \nJunior Resident, Department of Radio \ndiagnosis, SMC, Santosh deemed to be \nUniversity, Ghaziabad, Uttar Pradesh, \nIndia \n \nDr. Vidushi Jain \nJunior Resident, Department of OBG, \nSMC, Santosh deemed to be University, \nGhaziabad, Uttar Pradesh, India \n \n \n \n \n \n \nCorresponding Author: \nDr. Anoushka Gupta \nJunior Resident, Department of Radio \nDiagnosis, SMC, Santosh deemed to be \nUniversity, Ghaziabad, Uttar Pradesh, \nIndia \n \nAccessory cavitated uterine malformation: A rare \nmullerian anomaly-case report \n \nAnoushka Gupta, Ashish Kumar Shukla, Megha Sharma, Manvi Dhingra , \nJyoti Yadav, Prithvi Chauhan, Ranjeet Singh,  Shipra Chaudhary  and \nVidushi Jain \n \nDOI: https://www.doi.org/10.33545/gynae.2026.v10.i1c.1867  \n \nAbstract \nBackground: Accessory Cavitated Uterine Malformation (ACUM) is a rare Müllerian anomaly \ncharacterised by a non -communicating, endometrium -lined cavity within an otherwise normally formed \nuterus. Because external uterine morphology and menstrual flow often appear normal, ACUM is frequently \nmisdiagnosed as endometriosis, juvenile cystic adenomyoma, or fibroid degeneration. Patients typically \npresent with severe cyclic pelvic pain from adolescence, and symptoms often persist despite conventional \nmedical therapy. \nCase Report:  A 21 -year-old woman presented with progressively worsening dysmenorrhoea, recurrent \nlower abdominal pain, and irregular menstrual cycles. She had been treated elsewhere for one year as a \npresumed case of endometriosis, with only partial and temporary relief. On evaluation at our centre, \nultrasonography revealed a well -defined hypoechoic lesion (2.3 × 2.6 cm) with a central anechoic cavity \n(10 × 8 mm) located in the left upper lateral myometrium. MRI findings supported a diagnosis of a \ncavitated myometrial lesion compatible with ACUM. In view of persistent symptoms despite prolonged \nmedical therapy, surgical excision was performed. Gross pathology showed multiple soft -tissue fragments \ncontaining an intramyometrial cavity. Microscopy demonstrated an endometrial -lined cavity with \nhaemosiderin-laden macrophages and a surrounding myometrial wall, confirming ACUM. Clinical \npresentation, imaging, and histopathology together established the diagnosis. \nConclusion: This case underscores the need to consider ACUM in young women with refractory \ndysmenorrhoea, abdominal pain, or symptoms unresponsive to endometriosis treatment. Early recognition \nwith appropriate imaging and confirmatory histopathology facilitates timely surgical management, which \nremains curative and significantly improves quality of life. \n \nKeywords: Accessory cavitated uterine malformation, dysmenorrhoea, müllerian anomaly, \nintramyometrial cyst, case report \n \nIntroduction  \nAccessory Cavitated Uterine Malformation (ACUM) is a rare Müllerian anomaly characterized \nby a non -communicating, endometrium -lined accessory cavity within an otherwise structurally \nnormal uterus  [1]. The lesion is typically located beneath the insertion of the round ligament, \nsurrounded by a myometrial mantle, and separate from the main endometrial cavity  [2]. Because \nof its rarity and non -obvious external uterine distortion, ACUM is frequently misdiagnosed as \njuvenile cystic adenomyoma, noncommunicating uterine horn, degen erating fibroid, or \nadenomyosis [2, 3]. \nClinically, ACUM often presents in adolescents or young adults with severe, cyclical \ndysmenorrhoea or chronic pelvic pain, resistant to standard medical management  [4, 5] . The \naccessory cavity contains functional endometrium, which undergoes cyclical menstruation; \nbecause there is no outflow, blood accumulates leading to progressive distension, intracystic \nhemorrhage, and haemosiderin deposition - correlating with the worsening pain over successive \ncycles [1, 3] . Imaging plays a pivotal role in preoperative diagnosis. Transvaginal or 3D \nultrasonography may reveal a well -circumscribed intramyometrial cystic mass, while magnetic \nresonance im aging (MRI) is more definitive  showing a myometrium -surrounded cavity with \nblood-product signal intensity, a normal uterine contour, and a separate normal endometrial \ncavity [5, 6]. Despite these imaging tools, diagnosis is often delayed because many clinicians are \nunaware of ACUM’s distinct entity [2, 7].\n\n\nInternational Journal of Clinical Obstetrics and Gynaecology https://www.gynaecologyjournal.com \n~ 189 ~ \nBecause of recurrent pain and impact on quality of life, surgical \nexcision (usually via minimally invasive laparoscopy) is \nconsidered the treatment of choice, often resulting in complete \nsymptom relief while preserving uterine integrity [1, 4]. \nHence, we report this case to emphasize the classical \npresentation, imaging and histopathological findings of ACUM \nin a 21 -year-old woman with progres sive, refractory \ndysmenorrhoea aiming to raise awareness among clinicians to \nconsider ACUM in the differential diagnosis and ensure timely, \nfertility-sparing management. \n \nCase Presentation \nA 21 -year-old woman presented to us with a long -standing \nhistory of progressively worsening dysmenorrhoea. She \nadditionally complained of recurrent lower abdominal pain and \nirregular menstrual cycles, a combination that had increasingly \ninterfered with her daily routine. She had been treated elsewhere \nfor one year for a provisional diagnosis of endometriosis, during \nwhich she received conservative and hormonal therapies but \nobtained only partial and short-lasting relief. \nThe pain occurred with every menstrual cycle, typically \nbeginning on day one and persisting through the first few days \nof menstruation. Despite the use of over -the-counter analgesics \nand antispasmodics, she experienced only minimal and \ntemporary relief. The severity of pain resulted in recurrent \nhospital admissions, each episode characterised by sharp lower \nabdominal discomfort severe enough to restrict routine activities. \nShe denied any history of heavy menstrual bleeding, \nintermenstrual spotting, or passage of clots. She had no known \nhistory of genitourinary infections, hormonal treatment prior to \nthe past year, or previous pelvic surgery. No systemic symptoms \nsuch as fever, weight loss, or gastrointestinal disturbances were \nnoted. \nBecause her symptoms persisted despite prolonged treatment, \nshe presented to our centre for further evaluation. We performed \npelvic ultrasonography (USG) which revealed anteverted uterus \nof normal size and echotexture , without distortion of the main \nendometrial cavity. Within the left lateral myometrium of the \nupper uterine segment, a well -marginated hypoechoic lesion \nmeasuring 2.3 × 2.6 cm was identified. The lesion contained a \ncentral anechoic area of 10 × 8 mm, suggestive of fluid or \nhaemorrhagic content, surrounded by a uniform hypoechoic rim \napproximately 8 mm thick, consistent with a myometrial \nenvelope. The endometrial cavity was empty with a thickness of \n7 mm, appropriate for the phase of the menstrual cycle. Both \novaries were normal in size and morphology with no adnexal \nmasses or free fluid in the pouch of Douglas. \n \n \n(A) \n \n \n(B) \n \n\nInternational Journal of Clinical Obstetrics and Gynaecology https://www.gynaecologyjournal.com \n~ 190 ~ \n \n(C) \n \n \n(D) \n \n \n(E) \n \nFig 1: (A) to (E) Show ultrasound findings \n\nInternational Journal of Clinical Obstetrics and Gynaecology https://www.gynaecologyjournal.com \n~ 191 ~ \nBased on these findings, the radiologist considered the lesion \nhighly suggestive of an accessory cavitated uterine mass and \nrecommended MRI for further evaluation. MRI was \nsubsequently performed. \n \n \n \n \n \nFig 2: MRI Findings \n \nIn view of the typical imaging appearance along with her persistent symptoms despite prolonged medical therapy, surgical \nmanagement was planned.  \n \n \n\nInternational Journal of Clinical Obstetrics and Gynaecology https://www.gynaecologyjournal.com \n~ 192 ~ \n \n \n \n \nFig 3: Intra-operative images \n \nShe underwent surgical excision of the suspected mass, and the \ntissue was submitted for histopathological evaluation. On gross \nexamination, the specimen consisted of multiple soft -tissue \nfragments collectively measuring 4 × 2.5 × 1.5 cm. The cut \nsurface revealed a small cavity -like structure filled with altered \nmaterial. \nMicroscopic evaluation showed a well -defined cavity lined by \nthin endometrial epithelium, confirming the presence of \nfunctioning endometrial tissue. The stroma contained \nhaemosiderin-laden macrophages, indicative of repeated \nintracavitary bleeding. Surrounding the cavity were thick \nbundles of mature myometrial smooth muscle, sharply \ndemarcating the accessory cavity from the main uterine cavity. \nNo atypia, hyperplasia, or malignancy was noted. These features \nwere consistent with an Accessory Cavitated Uterine \nMalformation (ACUM). \nClinical symptoms, imaging findings, and definitive \nhistopathology together confirmed ACUM as the cause of this \npatient’s refractory and progressively worsening dysmenorrhoea. \n \nDiscussion \nIn retrospect, the clinical course of this patient closely fits the \npattern now recognised as characteristic of Accessory Cavitated \nUterine Malformation (ACUM), a Müllerian anomaly that \npredominantly affects adolescents and young women. What \ninitially appeared to be refractory d ysmenorrhoea and abdominal \npain symptoms for which she had already been treated as \npresumed endometriosis for nearly a year —ultimately reflected \nthe presence of a concealed, functioning accessory uterine \ncavity. This delay  in diagnosis is not surprising, as Timmerman \n\nInternational Journal of Clinical Obstetrics and Gynaecology https://www.gynaecologyjournal.com \n~ 193 ~ \net al . (2024)  [8] describe similar cases where ACUM manifests \nearly in reproductive life with severe cyclic pelvic pain that \nresponds poorly to conventional analgesics. Hu et al. (2024) [9] \nalso reported that many young patients undergo prolonged \ntreatment for dysmenorrhoea or endometriosis before the \nunderlying anomaly is identified. Our experience aligns with \nthese observations, reinforcing the need to consider ACUM in \nthe differential diagnosis of persistent, unexplained pelvic pain \nin young women. \nThe imaging features in our case were highly illustrative. The \nwell-defined intramyometrial cystic lesion with a central cavity \non ultrasound closely resembled descriptions by Gupta et al . \n(2023) [2], who noted similar lesions located near the round \nligament insertion. The MRI characteristics, including the \npresence of haemorrhagic content within a thick myometrial \nwall, matched the findings reported by Shen et al . (2025)  [11]. \nDespite this, ACUM is still frequently overlooked. Thakur et al. \n(2025)¹² noted that many cases are initially misinterpreted as \nadenomyosis, juvenile cystic adenomyoma, or cystic \ndegeneration of fibroids differentials that were also considered \nin our patient before deeper evaluation. Zhang et al . (2025)  [4] \nhighlighted this diagnostic uncertainty, emphasising that young \nwomen with disproportionate pelvic pain warrant targeted \nimaging to avoid misdiagnosis. \nHistopathology in our case provided definitive clarity. The \npresence of endometrial epithelium lining the cavity, \nhaemosiderin-laden macrophages, and a sharply demarcated \nmyometrial envelope was entirely in keeping with the diagnostic \ncriteria proposed by Zhu L et al. (2025) [13]. Similar microscopic \nfindings have been highlighted by Mondal and Bhave (2023)  [7] \nand Ferreira et al . (2025)  [14], who emphasised that recurrent \nintracavitary bleeding is central to symptom generation. The \nhistological picture in our patient strongly supports this \nmechanism, explaining her progressively worsening cyclical \npain despite treatment. \nSurgical excision proved to be the definitive therapeutic \nintervention. Our outcome aligns with published evidence: Hu et \nal. (2024)  [9] reported excellent symptom resolution following \nlaparoscopic removal of ACUM lesions, while Vidyasagara et \nal. (2025) [15] observed complete relief in similar cases. Rackow \n(2022) [1] has also stressed that early surgical management \nprevents prolonged morbidity and preserves normal uterine \narchitecture, particularly important for future fertility. From this \nexperience, it is evident that ACUM remains an underdiagnosed \nyet significant cause of severe dysmenorrhoea and pelvic pain in \nyoung women. This case underscores the importance of  \nmaintaining clinical suspicion especially when symptoms persist \ndespite standard therapy fo r conditions like endometriosis and \nhighlights the value of combining careful imaging interpretation \nwith histopathological confirmation to reach an accurate \ndiagnosis and offer effective, timely treatment. \n \nConclusion \nAccessory Cavitated Uterine Malformation remains an under -\nrecognised cause of severe pelvic pain in young women, and this \ncase clearly illustrates how easily it can be mistaken for more \ncommon conditions such as endometriosis. Our patient had been \ntreated for almost a year without meaningful improvement, and \nit was only when we correlated her persistent symptoms with \nfocused imaging and later histopathology that the correct \ndiagnosis became evident. Surgical excision proved curative, \nwith complete relief of her long -standing pain. This experience \nreinforces the importance of keeping ACUM in mind when \nevaluating young women with refractory dysmenorrhoea or \nunexplained abdominal pain, as timely diagnosis can prevent \nprolonged suffering and significantly improve quality of life. \n \nConflict of Interest: None. \n \nFunding: None. \n \nEthical Approval: Obtained. \n \nConsent: Written consent secured. \n \nReferences \n1. Rackow BW. Accessory cavitated uterine mass: a new \nmüllerian anomaly? Fertility and Sterility. 2022 Mar \n1;117(3):649–650. \n2. Gupta S, Kulshreshtha A, Kothari A, Shekhawat U, Shah D, \nMalhotra S. Accessory cavitated uterine malformation: a \ndiagnostic challenge of an unclassified rare presentation. \nInternational Journal of Reproduction, Contraception, \nObstetrics and Gynecology. 2025 Aug;14(9):3173–3176. \n3. Dekkiche S, Dubruc E, Kanbar M, Feki A, Mueller M, \nMeuwly JY, Mathevet P. Accessory and cavitated uterine \nmasses: a case series and review of the literature. 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The Journal of Obstetrics and \nGynecology of India. 2025 Apr;75(Suppl 1):589–591. \n \nHow to Cite This Article \nGupta A, Shukla AK, Sharma M, Dhingra M, Yadav J, Chauhan P, et al. \nAccessory cavitated uterine malformation: A rare mullerian anomaly -case \nreport. International Journal of Clinical Obstetrics and Gynaecology 202 6; \n10(1): 188-194.  \n \n \nCreative Commons (CC) License \nThis is an open access journal, and articles are distributed under the terms \nof the Creative Commons Attribution -NonCommercial-ShareAlike 4.0 \nInternational (CC BY -NC-SA 4.0) License, which allows others to remix, \ntweak, and build upon the work non -commercially, as long as appropriate \ncredit is given and the new creations are licensed under the identical terms.","source_license":"CC0","license_restricted":false}