Juvenile Granulosa Cell Tumor in a Three‐year‐old Infant An Immunohistochemical and Ultrastructural Study

Abstract

A three-year-old female infant with a juvenile granulosa cell tumor of the ovary and precocious pseudopuberty is presented. Laboratory tests revealed elevated levels of serum and urinary estrogen. Histological examinations showed an immature follicular pattern surrounded by theca-like stromal tissue. The immunohistochemical localization of estradiol, estriol, progesterone and testosterone was studied by indirect immunoperoxidase staining of cryostat sections. All of these steroid hormones were localized mainly in stromal cells and in some follicular cells. Electron microscopic examination revealed three types of tumor cell, i.e. polygonal cells, spindle cells and transitional cells. Well developed smooth endoplasmic reticulum, mitochondria with tubulovesicular cristae, and lipid droplets in the cytoplasm, which are typical features of steroid synthesis, were conspicuous mainly in the last type of cell. Such transitional cells almost corresponded to steroid-positive cells. These cells were considered to have a close relationship to theca gland cells of developed ovarian follicles and to have mainly participated in steroid synthesis in the present tumor. In addition, some spindle cells showed features of myofibroblasts, such as intracytoplasmic filaments, dense body-like structures, and pinocytotic vesicles. These features suggest that the cells might all be derived from the same progenitor of ovarian mesenchyme.