MACROSCOPIC DESCRIPTION: "Left distal tibia bone biopsy": Three fragments of firm red tissue 2-4mm in maximum dimension received with a separate fragment of firm pale tan tissue 4mm in maximum dimension. A1.

MICROSCOPIC DESCRIPTION: The fragmented biopsies contain islands of cartilage, which appear to be surrounded by lamellar cortical bone. There is no invasion through the cortex. The chondrocytes show no significant nuclear atypia. Binucleated cells are absent. There are no mitoses or necrosis. Myxoid change is absent in the background. The overall features are consistent with an enchondroma. No evidence of malignancy is identified. Radiological correlation is recommended.

DIAGNOSIS: Left distal tibia: Features consistent with enchondroma.