A case of rapidly growing osteosarcoma of the rib.

A 37-year-old woman noticed a right anterior chest mass and pain. The mass had been rapidly growing and she visited our hospital. The mass was hard and 8 × 7 cm in size. It was detected in the upper inner quadrant of her anterior chest wall. A computed tomography (CT) examination and magnetic resonance imaging (MRI) of the chest revealed a large heterogeneously enhanced mass arising from the right chest wall with lytic destruction of the rib and coarse calcification. An image diagnosis of osteogenic sarcoma originating from a rib was made. She underwent surgical excision of the tumor and chest wall reconstruction. Microscopic examination of the resected tumor showed multiple neoplastic cells accompanied by osteoid formation within the tumor. The tumor was diagnosed as high-grade malignant osteosarcoma of the rib. Primary osteosarcoma commonly originates in the long bone in children and adolescents, but it occurs very rarely in the ribs in adults. Surgical resection plays an important role in the treatment for this disease. We report a case of primary osteosarcoma that originated in the rib of a young woman and was treated successfully by surgery.