Vesiculitis, or inflammation, generally follows an attack of gonorrhea or of prostatitis. The tubules become dilated by a mucopurulent exudate, are congested and tender, and in chronic inflammation, there may be a connective-tissue formation. This through contraction may give rise to various deformities. Obstruction to the tubules as they enter the prostatic tissue causes the dilatation.

Tuberculosis may be primary or secondary to tuberculosis of the pulmonary or genito-urinary tracts. The bacilli gain lodgment by means of the blood-vessels or lymphatics. They are present in the semen and when contained within the vesicles infect them.

Tumors are seldom primary, usually being secondary to carcinoma of the prostate or rectum.