Sciatic and median nerve neurolymphomatosis as initial presentation of B-cell lymphoma

Neurolymphomatosis (NL) is the infiltration of cranial nerves or nerves and roots from the peripheral nervous system by lymphoma, usually by B-cell non-Hodgkin's lymphoma. It is uncommon as initial presentation of the disease and can lead to extremely heterogeneous clinical manifestations. We report the case of a 72-year old male who presented with numbness of the right hand, progressive weakness in both lower limbs and weight loss. 18F-FDG PET/CT showed bilateral hypermetabolic adrenal masses, gastric ulcer, small hypermetabolic adenopathies, multiple focal bone marrow uptake and intense uptake in both sciatic nerves and right median nerve. A node and gastric biopsy confirmed diffuse large-B-cell lymphoma, activated B cell type, with posterior resolution of peripheral nerves uptake after beginning chemotherapy.