Question 1:  What is the most likely diagnosis?

Discussion

In the right testis, there are three well circumscribed, round tumors, some with calcifications. The tumors measure about 1.2 cm at largest and show no vascularity using colour Doppler. They all have the classic “onion-peel” appearance of epidermoid cysts. In the left testis, there is a similar, but smaller tumor. No signs of testicular torsion.

Epidermoid cysts are rare benign testicular tumors, which account for around 1-2% of focal testicular lesions. Testicular epidermoid cysts usually present in the second to fourth decades, and often present as a painless enlargement of the testis [1-3].
Epidermoid cysts are solid tumors located beneath the tunica albuginea and they are typically surrounded by normal testis parenchyma. They have fibrous walls and the lumen contains keratin deposits [1]. Sonographically, the appearance of epidermoid cysts has classically been described as an “onion peel” appearance of alternating rings of hyper-and hypoechogenicity. At least three other appearances have been described, including a densely calcified mass, a cyst with peripheral rim or central calcifications, and a mixed-pattern cyst [4]. On elastography, epidermoid cysts appear hard [5].

Unlike most testicular neoplasms, epidermoid cysts are avascular [5, 6], and for this reason the use of colour Doppler is important in the differentiation from testicular neoplasms.

Unlike teratomas or dermoid cysts, epidermoid cysts do not contain any other teratomatous contents such as teeth, sebaceous glands or hair follicles [1, 3, 6]. It is important to recognize the appearance of testicular epidermoid cysts, as it enables treatment by enucleation. The patient underwent enucleation instead of orchiectomy and frozen sections were obtained during surgery confirming the benign diagnosis.
Testicular infarction would not show as focal well circumscribed lesions, but more as wedge shaped hypoechoic areas.

In the present case, the histopathological diagnosis of epidermoid cysts was indeed confirmed intraoperatively, and the four tumors (three from the right testis and one from the left testis) were enucleated while the rest of the testis parenchyma was left intact. Outpatient follow-up ultrasound showed no signs of recurrence.

Question 2: Given the fact that the patient had no other testicular lesions, and was otherwise well with an unremarkable medical history, what do you expect the blood work-up to show?