Extraovarian primary seromucinous cystadenoma masquerading as mesenteric cyst

We report an interesting case of extraovarian, primary seromucinous cystadenoma, which presented as a mesenteric cyst. A 31-year-old woman came with complaints of lower abdominal pain for 2 years, which is intermittent and aggravated during the menstrual cycle. On examination, her vitals were within normal limits; per abdominal examination revealed 7×7 cm mass in the right lumbar and right hypochondrium with well-defined margins. A Contrast-enhanced whole abdomen done showed a thin-walled of cyst of size 7×8×9 cm in the right lumbar region abutting and replacing the mesenteric border of ascending colon suggesting of mesenteric cyst. Patient underwent laparoscopic excision of mesenteric cyst. Histopathology revealed seromucinous cystadenoma without ovarian stroma.

obstetrics and gynaecology, general surgery

Seromucinous cystadenoma of the ovary is a new class of ovarian neoplasm introduced by WHO in 2014.1 These tumours exhibit both serous and mucinous features. These cases are frequently associated with endometriosis and involve both ovaries. Here, we present a rare case of primary seromucinous cystadenoma of extra ovarian origin, which presented as abdominal cyst. Surgical excision, either laparoscopic or open approach, remains mainstay treatment for such cases. Case presentation The patient was a 31-year-old woman with no known comorbidities presented with intermittent, dull aching lower abdominal pain for 2 years, which was insidious in onset, gradually progressive and aggravated during menstrual cycle. There was no abnormal vaginal discharge or change in bowel habits. She had undergone previous two lower segment caesarean sections. She had a history of cyclical pain during menstruation at Caesarean section scar site for which she had undergone scar excision and diagnosed to have scar endometriosis. On examination, her vital signs were within normal limits. On abdominal examination, right lumbar region tenderness presents, lower C section scar presents, a firm mass of size 7×7 cm in the right lumbar and right hypochondrium with well-defined borders was palpable, mass immobile. No free fluid was noted. Per vaginal and per rectal examinations were normal. Investigations Routine blood investigations were within normal limits. Contrast-enhanced CT of whole abdomen showed a thin-walled, nonenhancing cyst of size 6.7×7.5×9.3 cm, volume 233 cc in the right lumbar region abutting and displacing the ascending colon anteriorly and superiorly (figure 1A, B). Ovaries and fallopian tube were found to be normal and separate from the cyst, and two foci of scar endometriosis were seen. No pathologically enlarged abdominal, para-aortic or inguinal lymph nodes were noted. An imaging diagnosis of mesenteric cyst was made. Treatment Patient was taken up for laparoscopic excision of mesenteric cyst. A 5 mm camera port was made in palmer’s point, and a cyst of size 10×10 cm was noted replacing the medial border of ascending colon (figure 2A, B). Uterus was found adherent to the anterior abdominal wall with omental adhesions to the anterior abdominal wall and fundus of the uterus. Ovaries and fallopian tube were found to be normal. A 10 mm and a 5 mm working port were made in the left lumbar region and suprapubic region, and cyst was skeletonised from the surrounding structure. Cyst excised in toto. Specimen was sent for histopathological examination. On gross examination, the inner surface of the cyst wall was smooth with grey-white surface with no solid or papillary areas. Microscopic section of cyst showed cyst wall lined by cuboidal epithelium and focally by mucinous epithelium suggesting seromucinous cystadenoma (figure 3). No ovarian stroma was noted, and, hence, this is classified as extraovarian origin. Outcome and follow-up The patient was doing well after surgery and is on regular follow-up. Patient had a spontaneous conception 1 year following surgery. Ultrasound done showed a left adnexal mass of size 1.8×2.2 cm close to and separate from ovaries and yolk sac was seen. Cardiac activity present with haemoperitoneum in pelvis, suggesting ruptured ectopic pregnancy for which she underwent laparoscopic left salpingectomy.

The commonly occurring ovarian neoplasms are epithelial tumours that arise from the surface epithelium and adjacent stroma. In 2014, WHO classification of tumours of female reproductive organ introduced a new class of ovarian neoplasms called ‘seromucinous tumours’.1 2 Fox and Lange initially used the term seromucinous tumour in 1976.3 These tumours exhibit both serous and mucinous features and are composed of serous cells, endocervical type of mucinous epithelium, endometroid cells, squamous cells and undifferentiated cells.4 These tumours usually involve both ovaries and are usually associated with endometriosis.5 These tumours are seen in women of late reproductive age, and they usually present with nonspecific abdominal pain and discomfort.6 Seromucinous cystadenoma of the ovary accounts for about 1% of ovarian benign epithelial neoplasm.7 Primary benign seromucinous cystadenoma of abdomen is rare, and to our knowledge, no cases have been reported in the literature. This case is classified as extraovarian origin because of the absence of ovarian stroma on histology. Though the exact pathogenesis behind this tumour is not fully understood, it is postulated that the Mullerian or paramesonephric duct remnants deposited when the ovary descended during embryogenesis gives rise to these tumours.8 These tumours may be benign, borderline or invasive depending on the cytological features, presence or absence of invasion.9 The mainstay treatment for abdominal cyst is surgical removal. Aspiration of the cyst is not recommended. These cysts should be treated with the suspicion of malignancy and care should be taken not to rupture cyst intraperitoneally as it may lead to tumour spillage causing tumour seeding and development of pseudomyxoma peritonei. Learning points. We are presenting a rare case of extra ovarian seromucinous cystadenoma mimicking mesenteric cyst. Though intra-abdominal cysts are usually benign, a suspicion of malignancy should always be in mind as tumour spillage may worsen the prognosis. Despite in advantages of imaging studies, definitive diagnosis of cystadenomas is by histopathological examination. Footnotes Contributors: NA—chief surgeon, final approval. KJ—assisting the case, drafting the work. BH—assisting the case, draft revision. VB—assisting the case, draft revision. Funding: The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors. Competing interests: None declared. Provenance and peer review: Not commissioned; externally peer reviewed.

- 1.Kurman RJ, Carcangiu ML, Herrington CS. Who classification of tumours of female reproductive organs. International Agency for Research on Cancer: Lyon, 2014. [Google Scholar] - 2.Kurman RJ, Shih I-M. Seromucinous tumors of the ovary. what's in a name? Int J Gynecol Pathol 2016;35:78–81. 10.1097/PGP.0000000000000266 [DOI] [PMC free article] [PubMed] [Google Scholar] - 3.Fox H, Langley FA. Tumors of the ovary. Chicago: William Heinemann/Year Book, 1976. [Google Scholar] - 4.Lee J-C, Hung Y-C, Yeh L-S, et al. Ovarian seromucinous (Endocervical-Type mucinous and mixed cell-type) tumor: a case report. Taiwanese Journal of Obstetrics and Gynecology 2005;44:62–4. 10.1016/S1028-4559(09)60109-1 [DOI] [Google Scholar] - 5.Massicot R, Rousseau V, Darwish AA, et al. Serous and seromucinous infantile ovarian cystadenomas--a study of 42 cases. Eur J Obstet Gynecol Reprod Biol 2009;142:64–7. 10.1016/j.ejogrb.2008.09.007 [DOI] [PubMed] [Google Scholar] - 6.Seidman JD, Krishnan J. Ovarian epithelial inclusions with mucinous differentiation: a clinicopathologic study of 42 cases. Int J Gynecol Pathol 2017;36:372–6. 10.1097/PGP.0000000000000348 [DOI] [PubMed] [Google Scholar] - 7.Kurman RJ. International agency for research on cancer. World Health organization. who classification of tumours of female reproductive organs. Lyon, France: International Agency for Research on Cancer, 2014: 307. [Google Scholar] - 8.Pennell TC, Gusdon JP. Retroperitoneal mucinous cystadenoma. Am J Obstet Gynecol 1989;160:1229–31. 10.1016/0002-9378(89)90201-9 [DOI] [PubMed] [Google Scholar] - 9.Berenson AB, Edmonds DK, Pryse-Davies J. Seromucinous cystadenoma in a true hermaphrodite: a case report. Adolesc Pediatr Gynecol 1993;6:36–8. 10.1016/S0932-8610(12)80121-6 [DOI] [Google Scholar]