Dimorphism in Sex Chromatin Pattern of Sertoli Cells in Adults with Klinefelter's Syndrome: Correlation with Two Types of “Sertoli-Cell-Only” Tubules

Testicular biopsies from 16 patients with Klinefelter's syndrome were examined for the presence of sex chromatin in Sertoli cells. The examination revealed a dimorphism which could be correlated with the presence of two morphologically different types of tubules containing only Sertoli cells (Types A and B). Type A tubules invariably contained sex chromatin negative Sertoli cells. Type B tubules often, but not always, showed a high proportion of sex chromatin positive cells. Types A and B were often found together in the same biopsy, although in some biopsies only one of the two types was found.