Neurolymphomatosis associated with Sézary syndrome.

BACKGROUND Mycosis fungoides and Sézary syndrome are cutaneous T-cell lymphomas characterized by the epidermotropism of tumor cells. Neuropathic disease is rare during mycosis fungoides and Sézary syndrome and usually results from a central nervous system involvement in late stages. Neurolymphomatosis is defined as the infiltration of the peripheral nerves by tumor lymphocytes. It has been described in patients with aggressive systemic lymphomas but, to our knowledge, not in patients with mycosis fungoides or Sézary syndrome. We report the first case of neurolymphomatosis in a patient with Sézary syndrome and the partial efficacy of high-dose methotrexate sodium in treating this usually refractory complication. OBSERVATION A 73-year-old woman with newly diagnosed Sézary syndrome rapidly developed severe peripheral neuropathic disease with multiple paralyses. Biopsy specimens were taken from a clinically affected nerve and the adjacent muscle; they revealed a neural infiltration by Sézary cells with secondary muscular atrophy. Partial response and major neurologic recovery occurred and persisted under high doses of intravenous methotrexate until the patient died 14 months after the Sézary syndrome diagnosis from a pericarditis of uncertain origin. CONCLUSION This unusual and demonstrative case report highlights the possible neurotropism of malignant cells in Sézary syndrome and suggests the effectiveness of high doses of intravenous methotrexate in this rare and fatal disorder.