Metastatic endo and perineural involvement of the ulnar nerve from malignant melanoma: Ultrasound (US) and magnetic resonance imaging (MRI) findings

Malignant melanoma metastases occur in about 15% of patients. The most common localizations are lymph nodes, lungs, pancreas, bones. The central nervous system and the perineural region are rarely affected. In case of distant metastases, the survival rate is lower (about 25%). Involvement of peripheral nerve metastases from melanoma is reported in the literature just in one case. We report the ultrasound (US) integrated with Color-Doppler Ultrasound (CDU), elastosonography, and magnetic resonance imaging (MRI) findings of a rare case of metastatic endo- and perineural involvement of the ulnar nerve from cutaneous melanoma. Our purpose is to increase the clinicians' and radiologists' awareness on the possibility of metastatic spread to the peripheral nervous system and improve the differential diagnosis with other peripheral nerve sheath tumors