Bold takeaway: cystic ectasia of the rete testis is a benign, often incidental finding that can be mistaken for more serious testicular conditions—yet with careful imaging and history, unnecessary interventions can be avoided. And this is the part many clinicians overlook—understanding its classic ultrasound appearance helps separate it from tumors and other pathologies.
Introduction
The rete testis is a delicate, interwoven network of tubules in the hilum of the testis (the mediastinum testis) that channels sperm from the seminiferous tubules toward the vasa efferentia. Cystic tubular ectasia of the rete testis is a benign disorder characterized by multiple small cysts within this network. It typically presents on ultrasound as a cluster of small, anechoic structures at the confluence of the mediastinum testis, without any solid component and without color Doppler-detected blood flow. Most cases are asymptomatic and discovered incidentally during imaging.
Differentiating this condition from testicular tumors or other pathologies is crucial to avoid unnecessary surgery. The condition most commonly affects men over about 65, though cases in younger individuals have been reported.
In Sub-Saharan Africa, reports of cystic rete testis ectasia are relatively scarce. A 2021 case from Morocco documented cystic dilation of the rete testis, suggesting that while rare, this entity does occur in the region. The current report documents the sonographic features in a 66-year-old man.
Case Report
A 66-year-old man presented with a palpable testicular mass for one year to the radiology department of a teaching hospital. His medical history was unremarkable, with no prior hernia repair, vasectomy, epididymitis, or trauma. On examination, the right testis appeared swollen and firmer than the left, though no discrete lesion was palpable. Serum tumor markers (α-fetoprotein and β-human chorionic gonadotropin) were within normal limits.
Imaging was performed with a GE Healthcare VERSANA ESSENTIAL system using a 7–15 MHz transducer. Scrotal ultrasound included transverse and longitudinal views of the testes, epididymides, and spermatic cords, with color Doppler assessment. The right testis maintained normal size, but showed clustered, anechoic tubular structures within the rete testis. There were no solid components or calcifications, and Doppler imaging revealed normal blood flow. The right epididymal head appeared as a well-circumscribed, pure anechoic structure with a thin, regular wall measuring 20 mm by 14 mm, partially replacing the right epididymis. Fluid was also present in the right vaginalis. The left testis and epididymis were normal.
Overall, ultrasound favored a diagnosis of intratesticular cysts with tubular ectasia of the rete testis, associated with a regional epididymal head cyst and a localized hydrocele. The patient was managed conservatively, with follow-up scrotal ultrasounds planned.
Follow-up imaging at six months showed no interval change, and serum tumor markers remained unremarkable.
Discussion
The rete testis forms a complex network of seminiferous tubules within the mediastinum testis and drains via several efferent ductules that converge to form the head of the epididymis. Cystic tubular ectasia of the rete testis is a benign condition that predominantly arises in the sixth decade of life and is thought to result from age-related remodeling of the supporting fibrous and connective tissue within the testes. In this case, a 66-year-old man with no notable medical history and no children presented with the condition.
Autopsy and incidental surgical series have shown that cystic dilation of the rete testis occurs in a minority of cases (approximately 1.6%), reflecting its incidental nature in adults. Documentation from Sub-Saharan Africa remains limited; in Ivory Coast and neighboring regions, cases have been reported but are rare, potentially due to limited access to diagnostic resources and specialist care.
Pathogenesis is generally linked to obstruction at or distal to the efferent ductules near the epididymal head, leading to proximal dilation and tubular ectasia. Associations with conditions that obstruct the epididymis—such as vasectomy, spermatocele, or epididymitis—have been described, though not all patients have a relevant history.
Imaging characteristics typically show a peripheral, mediastinal-based tubular or cystic pattern without a focal solid mass. The rete testis is often seen as a peripherally located echogenic structure extending to the epididymal head; in some cases, it may appear anechoic with multiple tiny tubular spaces. There are no standardized size or quantity criteria for these cysts in radiology literature. Clinically, this entity is usually nonpalpable and frequently coexists with epididymal cysts or spermatoceles, predominantly in older men.
Differential diagnosis includes cystic dysplasia (a congenital lesion more common in children and linked to renal or urogenital tract malformations), intratesticular varicocele (distinguished on color Doppler by venous flow patterns), and the rare rete testis adenocarcinoma (which would typically present as a solid mass rather than tubular cystic changes).
In this case, the combination of imaging findings and history supported the diagnosis of cystic ectasia of the rete testis without pathological confirmation. Prior literature supports diagnosing this condition using the described clinical and ultrasound criteria.
Conclusion
Cystic ectasia of the rete testis, also called tubular ectasia, is benign and often discovered incidentally on ultrasound. It frequently accompanies epididymal obstruction from conditions such as vasectomy, spermatocele, or epididymitis. Despite its multifactorial and sometimes obscure origins, it is non-neoplastic and should be differentiated from testicular malignancies using clinical context (age and presentation), tumor markers, and imaging findings on grayscale ultrasound and Doppler assessment.
Awareness of the characteristic imaging features and its common associations helps prevent unnecessary tests, biopsies, and surgical interventions, supporting a conservative management approach when appropriate.
Consent
Written informed consent was obtained from the patient (or authorized representative) for publication of this case and accompanying images. A copy of the consent is available for review by the journal’s Editorial Office.
Ethics Statement
This case report adheres to ethical standards for research and publication. Patient information has been de-identified or appropriately protected to preserve privacy. The report complies with the Declaration of Helsinki and institutional guidelines for research involving anonymized patient data.
