[The testis in a 46, XX male. Apropos of an ultrastructural examination].

The ultrastructure of a testicular biopsy was carried out in a man with 46 XX chromosomes who had a masculine phenotype and in whom the hormone levels showed that the interstitial tissue of the gland was functioning well. Observations showed that the exocrine appearance of the testis was comparable to that described in Klinefelter's syndrome, namely germinal aplasia with invasion by Sertoli cells. On the other hand the interstitial glandular tissue showed morphological characteristics associated with normal androgen activity, which is unusual to find in Klinefelter's syndrome. Lipid inclusions, pigmentation and Reinke cristalloids were found. The cytogenetic techniques that happened to be used did not manage to show up even a small fragment of the Y chromosome. Various theories have been considered to explain the constitution of such a phenotype with this chromosome abnormality.