The vas deferens is a pair of ducts that carries sperm from the testes to the urethra during ejaculation. Contraction of its thick muscular wall propels sperm rapidly through the duct, which forms part of the spermatic cord. The differential diagnosis of calcification of the vas deferens includes:

» Diabetes mellitus: the most common cause, it results in bilaterally symmetrical calcifications within the muscular components, with preservation of luminal patency. Diabetes is thought to accelerate the process of senescent calcification of the vas deferens; therefore, calcification of the vas generally occurs in a younger patient population in diabetic males.

» Degenerative change (aging): indistinguishable in radiographic appearance from diabetic Ca++. By definition, these affected individuals have no evidence of diabetes or other predisposing factors (see below).

» Tuberculosis: intraluminal calcifications in the vas deferens occur after inflammation causes partial or complete thrombosis of the lumen of this structure. In contradistinction to #'s 1 and 2 above, calcification of the vas deferens related to tuberculosis is more likely to be unilateral and irregular.

» Other infections: gonorrhea, syphilis, schistosomiasis, and chronic nonspecific urinary tract infections. In such cases, like #3 above, the calcifications are intraluminal and are frequently unilateral and irregular in appearance.