Diagnosis and management of neurolymphomatosis.

Invasion of cranial nerves and peripheral nerve roots, plexus, or nerves by non-Hodgkin lymphoma is denoted as neurolymphomatosis (NL). Four clinical patterns are recognized. Most commonly, NL presents as a painful polyneuropathy or polyradiculopathy, followed by cranial neuropathy, painless polyneuropathy, and peripheral mononeuropathy. Diagnosis of NL is challenging and requires integration of clinical information, imaging findings, and histopathologic examination of involved nerves or nonneural tissue and cerebrospinal fluid analysis. In the rare cases of primary NL, the diagnosis is often delayed. Successful therapy is contingent upon recognition of the disease and its exact neuroanatomic localization without delay. Treatment options include systemic chemotherapy and localized irradiation of bulky disease sites. Concomitant involvement of cerebrospinal fluid and systemic disease sites requires more complex regimens.