Presentation
1.5 cm x 3 cm hard lump on medio-proximal end of tibia, non-mobile, has been there in the last 6 months at least
Patient Data
The clinically palpated lump correlates to a bony overgrowth from the medial proximal tibia with a cartilage cap measuring 4 mm in maximal thickness. This is in keeping with an osteochondroma.
Bony exostosis arising from the medial aspect of the proximal tibial metaphysis in keeping with an osteochondroma.
Case Discussion
It is essential to measure the thickness of the cartilaginous cap in cases of osteochondroma. This can be performed with ultrasound or MRI. A thickness of >1.5 cm is a worrying feature for malignancy (low-grade chondrosarcoma). Other features suspicious for malignant degeneration can be remembered with the mnemonic GLAD PAST.