Neuralgic Amyotrophy as the First Presentation of Lymphoma.

A 58-year-old man developed weakness and muscle atrophy in his left upper extremity after experiencing severe pain in the left shoulder. Magnetic resonance imaging (MRI) and positron emission tomography-computed tomography (PET-CT) revealed an abnormally swollen brachial plexus on his left side (A, B). Detailed examinations of blood test findings, including soluble interleukin-2 receptor, angiotensin converting enzyme, human immunodeficiency virus, tumor markers, proteinase3-antineutrophil cytoplasmic antibody, myeroperoxidase-antineutrophil cytoplasmic antibody as well as a cerebrospinal fluid study, including a cytological study, gastrointestinal endoscopy and colonoscopy, revealed no malignant or infectious disease (1). A diagnosis of neuralgic amyotrophy was made at that time. Although therapy with intravenous immunoglobulin, intravenous methylprednisolone improved his muscle weakness and neuralgic pain, severe pain recurred with gradual dose reduction of prednisolone. We performed careful follow-up. Fifteen months later, PET-CT showed a focal pathological uptake in the neck. Although we performed a biopsy twice at the lesion, no malignant disease, including lymphoma, was diagnosed based on the biopsy findings. Two years later, a skin lesion appeared on his right cheek (C) with a focal pathological uptake on PET-CT (D), and a pathologic diagnosis of B-cell lymphoma was made (E). Cognitive decline and gait disturbance were observed. Brain MRI showed brain lesions (F) with a focal pathological uptake on PET-CT (G), and a pathological examination of the brain lesion also showed B-cell lymphoma (H). Pathological images (E, H) showed anti-CD20 antibody staining. Although chemotherapy was administered, his neurological symptoms, including cognitive decline and weakness of the limbs, worsened. MRI showed brain atrophy (I, J). He ultimately died five years later. An autopsy was not performed. Although lymphoma is a major disease associated with neurological symptoms, it is difficult to diagnose in the nervous system (2,3). In the present case, repeated biopsies made a diagnosis of lymphoma possible.

The authors state that they have no Conflict of Interest (COI).