Androgen insensitivity syndrome - An immunohistochemical, ultrastructural,and morphometric study

Objective. - To evaluate the morphometric, immunohistochemical, and ultrast ructural lesions of the testes in prepubertal and adult patients with andro gen insensitivity syndrome. Methods. - We examined the testicular biopsy using immunohistochemistry for vimentin, smooth muscle actin, and collagen IV antigens. Quantification of seminiferous tubules and testicular interstitium was performed in prepuber tal and adult patients with androgen insensitivity syndrome and results wer e compared with normal testes from both infants and adults. Results. - The adult testes presented nodular and diffuse lesions that cons isted of Sertoli-cell-only seminiferous tubules. Two types of Sertoli cells could be distinguished, namely, immature vimentin-positive Sertoli cells a nd nearly mature Sertoli tells. In the nodules, the lamina propria was thin and contained a scant number of actin-positive peritubular cells. Leydig c ells were hyperplastic. The prepubertal patients showed only diffuse lesion s characterized by Sertoli cell hyperplasia, decreased germ cell numbers, a nd a discontinuous immunoreaction to collagen IV. Conclusions. - The testicular lesions in androgen insensitivity syndrome ar e probably caused by primary alterations that begin during gestation. These lesions become progressively more pronounced at puberty,when the nodular l esion pattern (adenomas) is completely developed.