epididymal cyst

Is the Lump on This Teenage Boy’s Testicle Malignant?

Case and images courtesy of David S. Gutierrez, MD, of Night and Day Pediatrics, San Antonio, Texas, and Alexander Yudovich, MD, and Larry Yin, MD, MSPH, of Children’s Hospital of Los Angeles.

epididymal cyst

THE CASE: A 14-year-old previously healthy boy presents to the clinic with a “lump on his testicle.” He had first noticed the lump 1 year earlier; it had not changed in size. He denies any trauma to the area, pain, or overlying erythema. Review of systems is otherwise normal.

Physical examination reveals a Tanner stage 3 uncircumcised male with testes descended bilaterally. A soft, mobile, 2 3 1-cm mass is noted above the right testis. The mass does not transilluminate or change with supine positioning or during a Valsava maneuver. The left hemiscrotum is unremarkable. There is no urethral discharge, lymphadenopathy, or gynecomastia.

Further evaluation with ultrasound imaging is done.

To which diagnosis do the findings point?

A. Hydrocele.

B. Hernia.

C. Epididymal cyst.

D. Varicocele.

E. Tumor.

(Answer on next page)

The correct answer is C, Epididymal cyst.

Discussion: The ultrasound examination revealed normal-appearing testes. Examination of the right testicle showed a thin-walled epididymal head cyst of 2 3 2.5 3 1 cm with debris (A). The absence of color flow helps rule out a varicocele (B). There were no calcifications in the cyst.

The differential diagnosis of scrotal masses includes epididymal cysts, hydroceles, hernias, varicoceles, and tumors. Doppler ultrasound examination is the imaging modality of choice for the evaluation of scrotal masses.1

Epididymal cysts are suspected when there is ultrasonographic evidence of a complex heterogeneous mass.2 Surgical intervention is usually unnecessary unless there is discomfort, pain, or progressive enlargement. The teenager in this case was asymptomatic and was referred to a urologist who recommended a scrotal ultrasound examination in 6 months.

Hydroceles are fluid collections within the patent processus vaginalis and are most often congenital; however, they can be acquired after trauma, infection, or in association with a tumor. They transilluminate and are nontender on examination. Most simple hydroceles resolve within 12 to 24 months.3 Surgical correction of hydroceles is recommended when the lesions persist beyond 2 years after presentation.3

Indirect hernias also result from a patent processus vaginalis. Physical examination may reveal swelling that extends along the inguinal canal and into the scrotum. The presence of abdominal pain and vomiting may indicate incarceration or strangulation of bowel. In the first year of life, the risk for incarceration is reportedly as high as 24%; thus, elective surgery is performed soon after diagnosis.4

Varicoceles are ectatic veins of the pampiniform plexus of the spermatic cord. They are usually asymptomatic; however, patients may experience a dull pain or a “heaviness” of the scrotum. On examination, a nontender “bag of worms” is palpable and decompresses when the patient is supine. A varicocele discovered prepubertally or on the right side may be indicative of an abdominal or retroperitoneal mass, which necessitates prompt evaluation. Adolescents with pain, large varicoceles, or loss of testicular volume should be considered for surgical therapy.5

The annual incidence of testicular tumors in children is 0.5 to 2 per 100,000.2 The differential diagnosis includes yolk sac tumors (most common), teratomas (second most common), embryonal carcinomas, teratocarcinomas, choriocarcinomas, mixed germ cell tumors, gonadal stromal tumors (most common nongerm cell tumor), and rhabdomyosarcoma.2 Other tumors involving the testes include leukemia/lymphoma (2% to 5% of testicular tumors2) and metastasis. Benign tumors are more common in children, whereas most tumors in adolescence are malignant. When pain is present, there may be associated torsion or hemorrhage into the tumor. n