[Diagnosis and differential diagnosis of testicular epidermoid cyst with MRI].

Objective: To investigate the MRI characteristics and differential diagnosis of testicular epidermoid cyst.

Methods: The MRI imaging features of 7 testicular epidermoid cyst cases were retrospectively analyzed and compared with that of testicular seminoma. All cases were examined by contrast-enhanced MRI scans.

Results: The group of 7 cases of testicular epidermoid cyst MRI showed characteristic: On T₁-weighted MR images, some lesions showed low signal-based, center with spotty high signal ("target sign"). On T₂-weighted MRI, some lesions had a laminated appearance, with alternating low and high signal intensity areas ("onion skin" sign). On contrast-enhanced images, all lesions were sharply demarcated low signal intensity masses, and contrast enhancement were not seen in any of the cases.

Conclusion: MRI characteristics of testicular epidermoid cyst are distinctive in certain extent. It may express "target sign", "onion skin" sign, T₂ low signal intensity complete rings, and without enhancement.