Serous cystadenoma is a benign epithelial tumour comprising cysts (≥10 mm) lined by non-stratified cuboidal or columnar cells that resemble tubule secretory epithelium. 1 They are a common neoplasm of the female genital tract, accounting for two-thirds of all benign ovarian epithelial tumours. 2 Within the testis, however, their occurrence is exceedingly rare. We present the case of a 37-year-old male who presented with a 6-week history of a growing, painful right testicular mass with concerning ultrasonographic features prompting a right radical orchidectomy. Subsequent histology and immunohistochemistry showed multiple cystic structures lined by ciliated columnar epithelium with both Mullerian and serous tubal-type expression profiles in keeping with a serous cystadenoma. There are approximately 60 combined cases of serous cystadenomas, serous borderline tumours and serous carcinomas arising from the testicular region. 3 To our knowledge, there are only three reported cases of serous cystadenomas arising from the testis itself. Serous cystadenomas follow a benign clinical course with no reported cases of tumour occurrence following orchidectomy. 3 Our patient was asymptomatic three months post-operatively and remains under close surveillance.
McLean et al. (Sun,) studied this question.