Primary Bone Lymphoma of the Shaft of the Tibia, Mimicking Subacute Osteomyelitis.

We present the case of a 32-year-old healthy male who presented with a three-month history of insidious onset pain and swelling over the right tibia. Initial radiographs and imaging pointed to a diagnosis of subacute osteomyelitis, as there was no cortical destruction, periosteal reaction, or soft tissue involvement. The patient underwent surgery for osteomyelitis. However, the histopathology and immunohistochemistry (IHC) findings pointed to a possible B-cell lymphoma diagnosis. The patient was referred to a tertiary-level oncology centre, where a repeat biopsy and positron emission tomography (PET) scan confirmed a diagnosis of primary bone lymphoma (PBL). Treatment was initiated immediately in the form of a combination of chemotherapy and radiotherapy, and the progress was followed up with further scans at four-month intervals. The patient achieved remission nine months after the initiation of treatment.