Proximal Tibial Osteochondromas in Patients with Fibrodysplasia Ossificans Progressiva

Abstract

Proximal tibial osteochondromas are a common phenotypic feature of fibrodysplasia ossificans progressiva, a finding that expands the recognized consequences of recurrent activating mutations in activin A receptor type I to include not only congenital skeletal malformations and heterotopic skeletogenesis but also benign osteochondral neoplasms or orthotopic lesions of skeletal modeling. The present study provides insight into the genetic basis of osteochondroma formation in patients with fibrodysplasia ossificans progressiva and possibly into that of more common conditions in which these lesions occur.