Maldescensus testis

Abstract

Maldescensus testis (MT) represents the most frequent congenital anomaly of the genitourinary tract and is found in roughly 1 % of mature and in up to 30 % of premature male neonates [ 1 ]. Maldescensus testis can be subdivided in two forms: retentio testis vs. ectopic testis (Fig. 47.1). Retentio testis describes an incomplete descensus of the testicles positioned within the physiological localizations of the embryological testicular pathway, i.e., abdomen (retentio testis abdominalis, “nonpalpable testis™), inguinal (retentio testis inguinalis), and prescrotal (retentio testis praescrotalis, “gliding testis™) regions. The clinical term “cryptorchidism™ is a synonym for MT [ 2 ]. Maldescensus testis has to be differentiated from retractile testis, a norm variant of descended testicles, predominantly localized in the scrotum and lifted into the inguinal regions by a strong cremasteric refl ex upon palpation [ 2 ]. Ectopic testis describes a complete descensus of the testicle; however, the testicles are misdirected outside the physiological embryological testicular pathway. While the most frequent localization in ectopic testis is the superfi cial inguinal region, it can be positioned in the perineal, femoral, or suprapubic region or in the contralateral hemiscrotum. Table 47.1 gives a brief summary of the several forms of MT.