Negative sural nerve biopsy in neurolymphomatosis

Patients With non-Hodgkin's lymphoma occasionally develop widespread invasi on of peripheral nerves by tumor cells or neurolymphomatosis (NL). Clinical ly this usually results in asymmetrical, progressive, and painful polyneuro pathy. Diagnosis rests on the identification of tumor cells in peripheral n erves. To avoid false-negative biopsy findings in patients with malignant l ymphomatous infiltration of peripheral nerves it has been recommended to bi opsy clinically involved nerves. We present two patients with histologicall y confirmed NL in whom sural the nerve biopsy finding was negative despite clinical and neurophysiological evidence: of involvement of the sural nerve a. The clinical features of NL are reviewed. Some patients with neurolypho matosis have only focal or proximal involvement of nerves, requiring the bi opsy of an affected part of these nerves. Magnetic resonance imaging may be useful in identifying affected nerves.