Diffuse skeletal muscle F-18 fluorodeoxyglucose uptake in advanced primary muscle non-Hodgkin's lymphoma.

A 65-year-old man newly diagnosed with primary muscular non-Hodgkin's lymphoma underwent staging F-18 Fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT). This demonstrated striking FDG uptake involving multiple skeletal muscles. Although a variety of factors may result in diffuse skeletal muscle FDG uptake, the heterogeneity and degree of FDG muscle activity, concomitant muscle enlargement, and clinical picture represent an unusual case of advanced primary muscular lymphoma.