後腹腔黏液性囊狀腺瘤合併神經內分泌特徵：病例報告及文獻探討

何岩¹、許軒豪¹、李良明¹、溫玉清^1,2、林克勳¹、林雍偉^1,2、石宏仁^1,2、賴宗豪¹

臺北市立萬芳醫院-委託財團法人臺北醫學大學辦理 泌尿科

Retroperitoneal mucinous cystadenoma with neuroendocrine features: a case report and review of the literature

Yen Ho¹, Syuan-Hao Syu¹, Liang-Ming Lee¹, Yu-Ching Wen^1,2, Ke-Hsun Lin¹, Yung-Wei Lin^1,2, Hung-Jen Shih^1,2, Chung-Howe Lai¹

Department of Urology, Taipei Municipal Wan Fang Hospital¹

Department of Urology, School of Medicine, College of Medicine, Taipei Medical University²

Background:

Retroperitoneal mucinous cystadenomas are extremely rare worldwide. The main objective of this study is to characterize the gross and microscopic features of the case.

Case Report:

This 32-year-old woman was no systemic medical histories before. She was found having a huge cyst in the right abdomen in regular prenatal sonography last year. She claimed that there was no other symptoms. After giving birth on June 11, 2020, she went to National Taiwan University Hospital where oophorectomy was suggested. Lab data revealed normal value in the tumor markers on September 30, including CA-199, CA-153 and CA-125. Transvaginal sonography was performed on December 4, which revealed a right ovarian cyst (139*92 mm). Diagnostic laparoscopy was performed by gynecologists on December 9, where we found a right-sided retroperitoneal cyst 14x9 cm. Abdominal and pelvic computed tomography showed a 11cmx17.6cm cystic lesion over the right retroperitoneum. Right retroperitoneal cyst excision was then performed by urologists on December 16, and we isolated the retroperitoneal cyst with small portion of wall thickening at the base. Aspiration of the cyst was done which resulted in clear fluid that later gelatinized with total volume of 480mL. No significant complications were present after the surgery. Pathology report revealed that the lesion mainly showed a picture of mucinous cystadenoma with cystic spaces lined by simple flat or mucinous columnar epithelial cells without nuclear atypia. In some regions, neuroendocrine cell proliferation is seen. The neuroendocrine cells are admixed with mucinous epithelium or form acini or solid nests in the stroma.

Discussion:

Retroperitoneal mucinous cystic neoplasm is a rare disease, which may be derived from secondary Mullerian system. Neuroendocrine cell proliferation has been never mentioned in the tumor in the literature. The diagnotic criteria of neuroendocrine tumor in the rare tumor has been not established. Mucinous cystadenomas can be located in the ovaries, pancreas, and in the retroperitoneum. According to the literature, symptoms are nonspecific, and most patients complained of an abdominal distension or mass with or without pain. Preoperative diagnosis is rather difficult, not because the tumors are often overlooked in the differential diagnosis but also because no sensitive methods or reliable markers are available. The histogenesis of retroperitoneal mucinous cystadenomas is controversial. Retroperitoneal mucinous cystadenomas are usually treated by laparoscopic or laparotomic surgical excision.

Conclusion:

We report the first case of retroperitoneal mucinous cystadenoma with some neuroendocrine features that has never been mentioned in the literature.