Ovarian sex cord tumor with annular tubules--a case report and review of the literature in Japanese.

A case of ovarian sex cord tumor with annular tubules (SCTAT) in a 41-year-old female is reported. The patient's chief complaint was menstrual irregularity, but the serum values of estradiol and testosterone were not elevated. On gross examination, the left ovary measured 8 x 7 x 6 cm in size and its cut surface was yellowish gray or yellow and solid with no cystic area. Histologically, the tumor was composed of simple and complex annular tubules, lined by columnar cells containing abundant lipid droplets. Eosinophilic materials in the center of the annular tubules were continuous with the basement membrane in the periphery, and showed immunoreactivity for type IV collagen. Also, hollow tubules, consisting of columnar cells with a truncated luminal surface and elongated trabeculae, composed of columnar cells with clear cytoplasm, were noted. These structures were reminiscent of Sertoli cell tumor. Based on these histological observations, it appears that SCTAT is a sex cord/stromal tumor made up of cells with differentiation in the direction of Sertoli cells rather than granulosa cells.