Juvenile granulosa cell tumor discovered during pregnancy: Case report with immunohistochemical study of steroidogenesis

A multilobular cystic juvenile granulosa cell tumor in a 33-year-old pregnant woman was examined. Pathological examination of the specimen at Cesarian section at 38 weeks of gestation revealed three different histological patterns; diffuse proliferation, trabecular or cord-like proliferation, and characteristic microfollicular patterns, as well as the presence of numerous luteinized stromal cells. These histological patterns were intermingled and transference among these patterns was detected. Immunoreactivity of steroidogenic enzymes including cholesterol side-chain cleavage, 3β-hydroxysteroid dehydrogenase and 17α-hydroxylase was detected only in luteinized stromal cells. However, that of adrenal 4 binding protein, a transcription factor of steroidogenesis, was present in almost all the tumor cells as well as luteinized stromal cells, suggesting that tumor cells acquired the potential of metabolizing and synthesizing steroid hormones. The hormonal environment associated with pregnancy altered the histological and biological features of this juvenile granulosa cell factor.