MRI and PET-CT in the diagnosis and follow-up of a lymphoma case with multifocal peripheral nerve involvement.

Lymphoma of the peripheral nerve, particularly of the T-cell variety, is an extremely rare subtype of extra nodal lymphoma that has a variable response to current therapeutic regimens. Here, we present a patient with natural killer (NK)/T-cell lymphoma in remission who presented with a two-month history of right forearm swelling and paresthesia in the ulnar nerve distribution. Magnetic resonance imaging (MRI) showed an ulnar nerve mass identified as a nerve sheath tumor.