- What does the clinical history tell you about the biologic behavior of this lesion?
The lesion is slow growing and benign.
- What is the diagnosis?
This is an osteochondroma, which characteristically has a cartilagenous cap over irregular trabecular bone. Radiographs demonstrate a bony exostosis growing from the lateral portion of the tibia, but there is no destruction of the tibia. All the elements are well-differentiated and benign. The cartilage and the trabecular bone both have normal cellularity without atypia.
- In whom and at what sites is this lesion most common?
There is almost a 2 to 1 male predominance. Peak incidence is teenage to young adulthood, but some occur in older persons. Most occur around the knee, and some in the humerus.
- What hereditary disease could be associated with multiple lesions of this type?
Osteochondromatosis (multiple hereditary exostosis) is an autosomal dominant condition in which patients have multiple osteochondromas. There is a small risk for sarcoma arising in this condition.
