Non-Hodgkin's lymphoma with pelvic skeletal muscle involvement presenting as low back ache: An uncommon presentation of a rather common malignancy

: Lymphoma with skeletal muscle involvement is a rare clinical presentation. They may occur as primary skeletal muscle lymphoma, contiguous spread from bones or by metastatic spread. We present a rare case of non-Hodgkin's lymphoma with pelvic skeletal muscle involvement presenting as low back ache. Lymphoma as the first differential diagnosis in this case was clinched after an 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) and confirmed as diffuse large B-cell lymphoma on histopathology. We seek to present an uncommon manifestation of lymphoma and highlight the role of 18F-FDG PET CT in the diagnosis, staging, and management of lymphoma.