Encysted spermatic cord hydroceles: a report of three cases in adults and a review of the literature. 
A hydrocele of the spermatic cord, which results from aberrant closure of the processus vaginalis, is an asymptomatic entity detected incidentally on computed tomography (CT)scans performed for other clinical indications.  There are two variations of a spermatic cord hydrocele: the "encysted" variety that does not communicate with the peritoneal cavity, and the "funicular" variety that does communicate with the peritoneal cavity.  The encysted type can be confused with an inguinal mass (lymphadenopathy, hernias), and also primary tumors of the cord.  We reviewed CT scans for all three adults and ultrasound images for one patient.  Confirmation of spermatic cord hydrocele was made by surgery in one case, and CT and follow-up CT in two cases.  Our findings indicate that a mass of the spermatic cord, showing fluid attenuation by CT and an avascular,anechoic appearance with sound transmission by ultrasound in an otherwise asymptomatic patient or even in those with an underlying malignancy, should prompt the radiologist to consider the diagnosis of spermatic cord hydrocele.  This may eliminate the need for unnecessary, highly invasive procedures such as biopsy or surgical exploration.