enchondroma

n. cartilaginous tumor within a bone (Medicine)

An Enchondroma is a cartilage cyst found in the bone marrow. Typically, enchondroma is discovered on a X-ray scan. Enchondromas have a characteristic appearance on Magnetic Resonance Imaging (MRI) as well. They have also been reported to cause increased uptake on PET examination.
See more at Wikipedia.org...

Enchondroma /en·chon·dro·ma/ pl. enchondromas, enchondro´mata a benign growth of cartilage arising in the metaphysis of a bone. [more]Enchondroma - Community and Resources

Noun
1. benign slow-growing tumor of cartilaginous cells at the ends of tubular bones (especially in the hands and feet)
(hypernym) benign tumor, benign tumour, nonmalignant tumor, nonmalignant tumour, nonmalignant neoplasm

(n.)
A cartilaginous tumor growing from the interior of a bone.