Morphology and histochemistry of infant testes in the prune belly syndrome

Testicular biopsy samples from 3 boys 5.5, 6 and 7 months old with the prune belly syndrome and intra-abdominal testes were examined morphologically and phenotypically for the presence of alkaline phosphatase. Findings were compared with those in age-matched autopsy controls. All patient specimens demonstrated atypical germ cells with large nuclei and prominent nucleoli, and intense alkaline phosphatase staining localized to the cytoplasmic membrane. The presence of these testicular abnormalities suggests that a developmental arrest is fundamental to the pathogenesis of the undescended testes associated with the prune belly syndrome. The similarity of the histological appearance of these testes to that of intratubular germ cell neoplasia suggests that long-term followup of these patients for the development of invasive germ cell tumors is important.