Malignant lymphoma in skeletal muscle with rhabdomyolysis: a report of two cases.

Malignant lymphoma is rarely found in skeletal muscle. In this article, we present two cases of malignant lymphomas that were located in skeletal muscle and caused rhabdomyolysis. One case was a primary skeletal muscle lymphoma (which is quite rare), and the other was a skeletal muscle metastasis of lymphoma. The patient with primary skeletal muscle lymphoma was diagnosed with a diffuse type of non-Hodgkin's lymphoma of T-cell origin, which may be linked to a history of injury. Both patients exhibited diffuse, homogeneous lesions of the affected muscles on computed tomography (CT) and magnetic resonance imaging (MRI). The blood levels of some enzymes and potassium, indicative of rhabdomyolysis, were elevated. Bone scintigraphy depicted widespread, diffuse accumulation of the radioisotope in the affected muscles of both patients, typical of rhabdomyolysis. Rhabdomyolysis may be a sequela of lymphoma, as a result of the tendency of malignant lymphoma to infiltrate diffusely into muscles, to affect multiple neighboring muscle compartments, and to metastasize into other soft tissues, as well as being a sequela of possible cytotoxic or humoral actions, all of which may increase the amount of muscle damage. When a patient presents with diffuse muscle swelling, one should consider a diagnosis of a hematogenous disease, which may cause rhabdomyolysis complicated by renal dysfunction.