[T-cell lymphoma revealed by a mononeuritis multiplex: case report and review of literature].

INTRODUCTION: Lymphoma occasionally affects the peripheral nervous system. Neuropathy usually appears in patients with known lymphoma but rarely represents the initial manifestation of underlying malignancy. We report a case in which mononeuritis multiplex (MM) was the dominant feature in the clinical presentation of a peripheral T-cell non-Hodgkin lymphoma (NHL). OBSERVATION: A 32-year-old man suffered from an asymmetric progressive sensory-motor peripheral neuropathy. The left peroneal nerve was affected first, then the left median nerve after one month, followed by the left trigeminal nerve ten months later. The electrophysiological study confirmed the diagnosis of axonal sensory-motor MM. Mediastinal adenopathies, splenomegaly, pancytopenia and inflammatory syndrome were also found. An osteo-medullary biopsy showed a T-cell NHL. Nerve biopsy study found an inflammatory lymphoid infiltration without malignant cell supporting the hypothesis of an inflammatory pathogenic process. Chemotherapy including cyclophosphamide, hydralazine, vincristine and prednisone were administered monthly during 8 months. No improvement was obtained. DISCUSSION: It must be emphasised that this case is an uncommon one. On the one hand, NHL is rarely associated with MM and on the other hand, it can exceptionally be revealed by a MM. We were able to find 30 reported cases of distal neuropathy revealing a NHL including, 8 mononeuritis simplex, 9 MM and 13 polyneuropathies. Polyradiculoneuritis cases were excluded from this study because the neuropathy is usually caused by a meningeal infiltration. The neuropathy was in the majority of the cases chronic and axonal. The lymphoma was more often B-cell than T-cell. The B-cell lymphoma was frequently associated with a poor prognosis. All mechanisms were present with a predominance of neurolymphomatosis.