Spinal Accessory Neuropathy Secondary to Diffuse Large B-Cell Lymphoma

ABSTRACT

Spinal accessory neuropathy (SAN) is commonly caused by an iatrogenic procedure, and that caused by tumors is very rare. We present a case of a 49-year-old man suffering from weakness in the right trapezius and sternocleidomastoid muscle. An electrophysiology study confirmed proximal SAN. Fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) revealed a diffuse large B-cell lymphoma compressing the right spinal accessory nerve. Ultrasonography showed definite atrophy on the trapezius and sternocleidomastoid muscles. In addition, post-chemotherapy FDG-PET/CT showed increased FDG uptake in the right upper trapezius, suggestive of denervation. This is the first report of SAN caused by direct compression by a diffuse large B-cell lymphoma, comprehensively assessed by an electrophysiology study, ultrasonography, and FDG-PET/CT.