Presentation
Left upper medial leg swelling.
Patient Data
A large cauliflower-like mass is projecting from the anteromedial cortex of the proximal tibial metaphysics. It elicits low signal on T1 and T2 WI with heterogenous post-contrast enhancement. Adjacent cortical thickening and sclerosis are noted.
on CT, the lesion appears densely calcific with adjacent cortical sclerosis.
Case Discussion
The diagnosis was confirmed by biopsy.
Parosteal osteosarcoma is a subtype of osteosarcoma and arises from the outer layer of the periosteum.
The diagnosis of parosteal osteosarcomas is based on a combination of typical histological and radiographic features