Benign bilateral testicular enlargement

Detailed investigation was made of a pubertal patient with unusually large testes. No abnormality of adrenal or Leydig cell function was found. There was no evidence for autonomy of either pituitary or gonad. Testicular biopsy showed tubules of adult diameter with a paucity of mature germinal elements, spermatogonia with ballooned cytoplasm, and Sertoli cells with retracted apices. These findings suggest that this patient exhibits a previously unreported and apparently benign process affecting tubular development and giving rise to megatestes.