Diffuse Large B-cell Lymphoma Involving the Skeletal Muscle.

A 65-year-old man was referred to our hospital with extensive swelling of the left leg (Picture A). His serum levels of lactate dehydrogenase and soluble interleukin-2 receptor were elevated to 1,000 IU/L (reference range, 120-240 IU/L) and 3,922 U/mL (reference range, 122-496 U/mL), respectively. Magnetic resonance imaging of the leg showed an enlarged left thigh composed of the quadriceps femoris muscles with a high-intensity area (Picture B, arrows) and the femoral bone, with heterogenous spots on T2 images (Picture C, arrows). Positron emission tomography-computed tomography identified high uptake of 18F-FDG (SUVmax, 13.25), predominantly in the muscles of his left thigh and also in the supraclavicular, subclavicular, and abdominal lymph nodes (Picture D). Following a biopsy of the left supraclavicular lymph node, a diagnosis of diffuse large B-cell lymphoma was made. Non-Hodgkin's lymphoma involving the skeletal muscles is rare, accounting for 1.4% of all lymphomas (1,2). It is therefore important to consider the possibility of lymphoma in patients with unilateral leg swelling.

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