RESUMEN
Cryptorchidism is a risk factor for testicular cancer and reduced fertility. Failure of critical maturation steps, with the persistence of gonocytes beyond 6 months, results in a decreased number of adult dark (A-dark) spermatogonia, which causes a deficiency of primary spermatocytes at 3 years of age. We evaluated the histological findings in boys older than 4 years who were diagnosed with a testis located in the inguinal channel. From September 2007 to September 2008, 15 boys (mean age 8 years) underwent orchidopexy with a biopsy taken from the undescended testis of one side. Sonograms were performed in all 15 boys. The incidences of spermatogonia, primary spermatocytes, and Leydig cells (semiquantitative) were estimated as well as the exclusion of intratubular carcinoma in situ cells (Department of Pathology, Central EM Lab, University Medical Center Regensburg, Germany). Orchidopexy was performed on the right side in eight boys, the left side in one, and both sides in six. Sonographically, no parenchymal echotexture abnormalities were found. A-dark spermatogonia could be detected in nine biopsies. The Leydig cell score was reduced in 11 boys. No carcinoma in situ cells were detected. Late diagnosis of undescended testis will have a poor prognosis for future fertility.