Exploratory laparoscopy is the gold standard for diagnosis. It is used to scan the abdomen for blind-ending spermatic vessels and vas deferens (confirms testicular regression) or a hidden abdominal testis. Monorchidism or unilateral anorchidism - Springer Nature
A common hypothesis is that the testis undergoes twisting (torsion) during fetal development, leading to ischemic necrosis (tissue death) and subsequent absorption of the tissue.
Diagnosis is challenging because anorchia presents similarly to severe intra-abdominal cryptorchidism. Initial detection of empty scrotrum. anorchidism
The primary sign is the inability to feel one or both testes in the scrotum.
Absence of one testicle. This is much more common, accounting for approximately 4% of all non-palpable testes cases. Exploratory laparoscopy is the gold standard for diagnosis
Because the testes existed early in development, they produced necessary Testosterone and Anti-Müllerian Hormone (AMH), resulting in normal male external genitalia.
Absence of both testicles. This is rare, occurring in roughly 1 in 20,000 males. Causes and Etiology Absence of one testicle
Ultrasound can be used initially, but it often fails to identify the vanishing testis.