MRI of testicular epidermoid cyst.

This report presents and discusses the magnetic resonance imaging (MRI) and pathological findings of a case of testicular epidermoid cyst. A 35-year old man consulted a physician after he felt an enlargement of the right testis. Physical examination revealed a painless, non-tender, elastic hard mass in the right testis. A radiological examination was performed. MRI demonstrated an enlarged right testis, with a mass in it. The mass showed slightly low signal intensity on T1-weighted imaging, and high signal intensity on T2-weighted imaging. Both the T1- and T2-weighted images revealed a peripheral low signal intensity rim. The mass showed no enhancement. A right orchiectomy was carried out for epidermoid cyst. Pathologic examination showed a well-encapsulated nodule within the right testicular parenchyma, filled with a cheesy, yellow-white material similar in appearance to atheroma. The bull's-eye appearance is considered to depend on the presence of calcification. From the viewpoint of pathology, testicular epidermoid cysts do not always show bull's-eye. We then must recognize that some testicular tumors may be epidermoid cysts even without the bull's-eye findings.