Fragments of mature cortical and remodeling cancellous bone tissue exhibiting prominent reactive changes. There is a marked irregular thickening of the bone trabeculae, demonstrating active woven bone formation extensively lined by a uniform, orderly layer of plump, active osteoblasts (osteoblastic rimming). The intervening fibrovascular medullary spaces and periosteal zones are heavily infiltrated by a dense, polymorphous inflammatory exudate. This infiltrate is composed predominantly of mature plasma cells, lymphocytes, and histiocytes, accompanied by focal vascular proliferation and granulation tissue formation. Areas of bone necrosis (sequestrum) are identified, characterized by empty osteocyte lacunae and irregular, eroded bony margins undergoing active resorption by scattered multinucleated osteoclasts. No evidence of specific granulomas. No evidence of atypia or malignancy.
The contrast-enhanced CT of the left tibia demonstrates midshaft diaphyseal cortical destruction, irregularity, sclerosis, and intramedullary changes with a significant periosteal reaction and mild surrounding edema (without abscess formation), highly characteristic of osteomyelitis, with tuberculosis as the primary differential diagnosis.
Bone fragments collectively measured 3.7x2.8x1 cm, totally embedded.
Lt. Midshaft of tibia lesion, Biopsy: