Fetal gonadoblastoid testicular dysplasia: a focal failure of testicular development.

Fetal gonadoblastoid testicular dysplasia (FGTD) is an extremely rare lesion, which, in its original description, appeared in association with hydrops fetalis and other malformations. Its phenotype strongly resembles gonadoblastoma, although in contrast with that rare tumor, FGTD is not associated with the intersexual states or gonadal dysgenesis that accompany such neoplasm. Two reports described an association of FGTD and a morphologically similar lesion with Walker-Warburg syndrome. However, we have not confirmed such an observation, although a nonspecific muscle disorder was found in one of the examples we describe in this article. Here we study 2 additional cases, providing a detailed topographical, histomorphological, and immunophenotypical analysis. A review of all 5 previously described cases is conducted. The features of this lesion support the notion that a focal defect in testicular development is its most likely pathogenesis.