The tunica albuginea is a dense fibrous sheath that surrounds, covers and protects the delicate contents of each testicle. The tunica albuginea is surrounded by a second layer, the tunica vaginalis. Tunica cysts, which are benign cystic masses, may arise from either tunic.
What is a tunica cyst?
Tunica cysts originate from the tunica albuginea and are the most common benign masses that originate external to the testicle. They are small, firm, irregular, plaque-like nubbins located on the surface of the testes ranging from 2 to 5 mm in size. They are often described as feeling like a grain of rice, and are most often found on the upper-front or upper-side aspect of the testicle. In most cases, they are not symptomatic and are discovered incidentally by the patient, who is typically around 40 years of age.
How are tunica cysts diagnosed?
Tunica cysts can cause a great deal of concern and worry because of the fear of testicular cancer, but they are distinguished from testicular cancer by being cystic (not solid) and on the outer surface of the testes as opposed to being within the testes. Ultrasonography is the imaging study of choice for evaluating testicular masses and can differentiate cystic, benign masses from solid, malignant masses.
On ultrasound, the tunica albuginea can be seen as a 2-layered echogenic (containing lots of echoes) structure surrounding the testicle and the cyst as a small, regular fluid-filled structure abutting the surface of the testicle. On occasion, a tunica cyst may calcify. Microscopically, they are seen to contain fluid and cellular debris.
How are tunica cysts treated?
Although tunica cysts can be surgically removed, it’s rarely necessary to do so because ultrasound can reliably confirm their benign diagnosis. Make an appointment with your urologist if you notice any testicular bumps or lumps during a self-exam.