Periosteal osteosarcoma: a review of clinical evidence.

Periosteal osteosarcoma (PO) is a rare primary malignant bone tumor and a variant of osteosarcoma. It is a surface lesion without evidence of medullary involvement. The radiologic appearance of periosteal osteosarcoma is a broad-based surface soft-tissue mass that causes extrinsic erosion of thickened underlying diaphyseal cortex and perpendicular periosteal reaction extending into the soft-tissue component. The tumour presents as non-homogeneous masses of speculated osteoid matrix progressively denser from the periphery to their cortical base. The average age is around 28 and the most common location is the proximal third of the femur; with all the lesions diaphyseal in location. The treatment usually indicated is amputation, but in selected cases, radical segmental resection is appropriate. Long-term disease-free survival is possible after resection of the local recurrence. Limb-salvage therapy seems to offer survival equivalent to amputation, and there does not seem to be a substantial risk of late recurrence, dedifferentiation, or disease progression. The current review also highlights on various rare occurrences of periosteal osteosarcoma including the one of calcaneum, fifth metatarsal, mandible cranium, jaws, clavicle, maxilla, sphenoid bone with extensive periosteal extension, metacarpal in a paediatric age group and bilateral metachronous periosteal osteosarcoma. Recent findings relating to genetic factors governing the pathogenesis of PO is also presented.