Pathogenesis of the Prune-Belly Syndrome: A Functional Urethral Obstruction Caused by Prostatic Hypoplasia

Abstract

Abdominal muscle deficiency, urinary tract abnormalities, and cryptorchidism are the three major features of the prune-belly syndrome, also referred to as triad syndrome or Eagle-Barrett syndrome. The etiology is unclear and the pathogenesis a subject of continuing debate. Clinical and pathologic experience with seven cases of prune-belly syndrome is reviewed. Findings indicate that the urogenital anomalies can be attributed to a functional urethral obstruction which in turn is the result of prostatic hypoplasia. The histology of the abdominal wall is that of atrophy—ie, the degeneration of already formed muscle—and not of primitive muscle. This observation supports the theory that the abdominal muscle hypoplasia is a nonspecific lesion, resulting from fetal abdominal distension of various causes. Transient fetal ascites may be an important feature of the prunebelly syndrome.