[Tubular ectasia of rete testis: a pitfall in ultrasonographic diagnostics of intratesticular cysts].

Background: Tubular ectasia of the rete testis (TERT) sonographically consists of a cluster of anechoic foci located at the mediastinum testis. TERT is important diagnostically, because it might be confused with malignant teratoma that may likewise contain cystic areas.

Patients And Methods: Twenty-four patients with TERT were identified sonographically. Ten of these patients underwent additional magnetic resonance imaging (1.5 T), and three had contrast-enhanced scrotal sonography. A descriptive analysis was done regarding clinical details and sizes of the single anechoic foci and of the entire areas involved with cystic changes.

Results: The median age of the patients with TERT was 60 years. Diagnosis was based on incidental findings or uncharacteristic symptoms in three quarters of the cases. The size of the single cysts was ≤ 3 mm, 4-6 mm and ≥ 7 mm in 12, 6 and 6 patients, respectively. The size of the entire area involved with cystic changes ranged from 0.5 x 1.2 cm to 2.5 x 3.0 cm. Six patients had TERT bilaterally, and 18 had concomitant spermatoceles. T2-weighted MRI demonstrated high signal intensity of the cystic areas. No signal enhancement was found in these areas after application of contrast agent. Contrast-enhanced sonography did not show uptake in the TERT areas. Histological evidence for dilatation of the rete testis was found in the two patients undergoing diagnostic surgery.

Conclusions: TERT is a benign lesion of the testis that is increasingly detected sonographically. Knowledge of TERT is essential for the urologic sonographer to avoid unwarranted diagnostics and surgery as well as costs.