2. Department of Obstetrics & Gynecology, Takayama Red Cross Hospital, 3-11 Ten-man-cho, Takayama City 506-8550, Japan.
3. Department of Obstetrics & Gynecology, Gifu University School of Medicine, 1-1 Yanagido, Gifu City 501-1194, Japan.
4. Section of Laboratory Medicine, Gujo City Hospital, 1261 Shimadani, Gujo City 501-4222, Japan.
5. Department of Diagnostic Pathology & Research Center of Diagnostic Pathology, Gifu Municipal Hospital, Gifu City 500-8513, Japan.
Benign cystic mesotheliomas (BCMs) are extremely rare tumors usually occurring in females of reproductive age. A 13-year-old Japanese girl presented with abdominal pain, and an adnexal cystic tumor was suggested by images. At laparoscopy, the cystic mass was found arising from the lesser omentum. Histological examination and calretinin-immunohistochemistry revealed the lesion as a BCM. Cytology was initially useful for the diagnosis. This is a benign pathology, but recurrences are not uncommon. BCM should be included in the differential diagnosis, when investigating pelvic and abdominal masses associated with adnexal tumors in women.
Keywords: Benign cystic mesothelioma, omental tumor, cytology, calretinin