Testicular juvenile granulosa cell tumor in a newborn: case report and review of the literature.

Juvenile granulosa cell tumor of the testis of neonates and infants is an uncommon lesion frequently associated with abnormal sex chromosome and ambiguous genitalia. This report describes a juvenile granulosa cell tumor arising in the testis of a neonate. Chromosome analysis of the tumor showed a normal male karyotype 46 XY. Histopathology and immunohistochemical studies revealed the occurrence of 2 well-differentiated epithelial-like and smooth muscle-like components in the neoplasm. The morphologic clues leading to the correct diagnosis of juvenile granulosa cell tumor and the possible histogenesis are briefly discussed.