Involuting luteinized thecoma of the ovary.

Spontaneous tumor involution in ovarian stromal tumors is a poorly understood phenomenon. In this report, we describe a rare case of luteinized thecoma that showed extensive involutional changes, such that cellular elements diagnostic of luteinized thecoma were sparse. The convoluted contour of the tumor resembled that observed in a corpus albicans; however, the neoplasm was considerably larger, and the contents of the nodule differed from that of a corpus albicans. The diagnosis of luteinized thecoma was established by the identification of residual aggregates of neoplastic theca cells and a nodule of lutein cells that were positive for inhibin and steroidogenic factor-1. Features of involution within the tumor included a few theca and lutein cells with pyknotic nuclei and abundant cytoplasmic lipid, occasional large adipocytes among the lutein cells, extensive hyalinization, dystrophic calcification, a myxohyaline nodule, and adipose metaplasia. It is likely that some of the aforementioned changes are the result of accompanying ischemia. Cleaved caspase-3 staining patterns were negative within residual lutein and theca cells; thus, we were unable to establish the occurrence of apoptotic bodies.