Spontaneous regression over time of the germinal epithelium in a Y chromosome-microdeleted patient

Azoospermia factor (AZF) region microdeletions, which account for about 10- 15% of patients with oligoazoospermia, seem to lack a close genotype-testic ular phenotype correlation. Although many genetic and non-genetic factors m ay contribute to this outcome, it was thought that a spontaneous regression of testicular germ cells might also play a relevant role. The opportunity for carrying out two different testicular biopsies one year apart in an AZF c-microdeleted patient enabled corroboration of this possibility. Indeed, t he first biopsy showed a spermatocyte maturation arrest with mean Johnsen s cores of 4 and 3.9 in the right and left testes respectively. One year late r, the right testicular biopsy showed a picture of Sertoli cell-only syndro me in 90% of the tubules examined, and of spermatogonial maturation arrest in the remaining tubules, with a mean Johnsen score of 2.1. The almost comp lete absence of germinal cells was confirmed by four left testicular sperm aspirations (TESA), conducted at the same time as the biopsy during an intr acytoplasmic sperm injection cycle, which showed the almost exclusive prese nce of Sertoli cells (85% of the whole cell population). No spermatozoa cou ld be retrieved by TESA or testicular biopsy. To our knowledge, this is the first case of a spontaneous regression of the germinal cell epithelium ove r time in a patient with a Yq microdeletion without the apparent interventi on of any cause known to affect the germinal epithelium.