Osteochondromas are primary cartilaginous neoplasms that induce growth of underlying bone and marrow.  These are usually benign, but cartilaginous overgrowth / thickness of cartilaginous cap may be a sign of malignant transformation.

Triage & Gross

• These specimens usually demonstrate a bony resection margin at the base, leading into a bony stalk with a multi-lobulated cauliflower-like protrusion ending in a cartilaginous cap.
• Measure the specimen in 3 dimensions.
• Ink the bony resection margin.
• Serially section the specimen perpendicular to the cartilaginous cap.
• Measure the thickness of the cap (range of thinnest to thickest).
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• Take note of any cartilaginous overgrowth. This feature is predictive / indicative of secondary chondrosarcoma arising in an osteochondroma.
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• Submit representative sections of cap, adjacent marrow, and margin.
• Decalcify after fixation.  Don’t forget to state “after decalcification” in your dictation and add the Decal “stain” to the appropriate blocks in Copath.