Epididymal adenomatoid tumor: a case report and literature review
Chan-Jung, Liu; Ho-Shiang, Huang
National Cheng Kung University Hospital Department of Urology
A 64-year-old man presented to the urology department with progressive right testicular enlargement for 6 months. No associated testicular pain or fever was mentioned. His physical examination was unremarkable, except for a small nontender intratesticular mass at the middle pole of right testis. Pelvic computed tomography revealed fluid accumulated in right scrotum with septum formation. No obvious intratesticular mass was found. Serum tumor markers, including alpha-fetoprotein, beta-human chorionic gonadotropin, and lactate dehydrogenase, were all within normal limits. The patient subsequently underwent right testicular exploratory surgery. During the surgery, one cystic mass protruded from lateral side of right testis. The final histology resection revealed an adenomatoid tumor growing from the epididymis.
Adenomatoid tumors are the most common paratesticular neoplasms and involve approximately 30% of all paratesticular masses. There are several theories about their histogenesis: mesothelial, Müllerian, mesonephric, and endothelial origin. The mesothelial origin is the most widely accepted. Adenomatoid tumours usually involve the genitourinary system in both males and females. Fallopian tubes, ovaries and uterus are common areas for females, and epididymis, testes, spermatic cord, ejaculatory ducts are common in males. These tumors are usually located in the tail part of the epididymis usually as a separate mass with a mean age of presentation between 30 to 40 years. Clinical presentation can vary from asymptomatic small masses to very painful masses in the scrotum region which can be confused for torsion. Ultrasonography is the initial investigation of choice with high sensitivity and specificity rates. Ultrasound examination demonstrates well circumscribed uniformly hypoechoic mass, that are usually avascular but may demonstrate internal vascularity on colour flow Doppler imaging. MRI helps in diagnosis as the lesion appears hypointense to surrounding parenchyma arising from testicular surface and enhances less than the normal testis on post contrast administration. By considering rare benign intratesticular tumors in the differential diagnosis of testicular masses, normal levels of preoperative serum tumor markers combined with intraoperative histologic examination can offer the surgeon to clues of this rare benign tumor. The intraoperative frozen section should be considered.