Published online Aug 18, 2015. doi: 10.5312/wjo.v6.i7.559
Peer-review started: March 2, 2015
First decision: May 14, 2015
Revised: June 6, 2015
Accepted: June 18, 2015
Article in press: June 19, 2015
Published online: August 18, 2015
A case of florid reactive periostitis ossificans (RPO) arising in a long bone is presented. This is a rare bone proliferation with a pronounced periosteal reaction. Less than 100 cases have been described in the literature with far fewer outside the bones of the hand, feet, fingers, and toes. Although the etiology is unknown, a relationship to preceding trauma is suggested. The imaging and histologic features show an overlap with other bone lesions including bizarre parosteal osteochondromatous proliferation, subungual exostosis, and malignant surface tumors of bone and cartilage which include, periosteal and parosteal osteosarcoma. It is important to recognize the clinical presentation and diagnostic features of RPO as a benign entity so that it is not mistaken for a more aggressive neoplasm. We present a case of a right distal humeral lesion that on histopathological review revealed florid RPO. This diagnosis was not suspected on imaging studies, but was made on open biopsy of the mass. The patient remains disease free, years postoperatively. In addition to presenting this unique case report, we review the pertinent literature, and offer a differential diagnosis and treatment strategy for its management.
Core tip: Florid reactive periostitis ossificans (RPO) is a rare benign entity that is classically localized to the phalanges of the distal extremities. This lesion is often clinico-radiologically and histologically confused for malignant entities, like osteosarcoma and chondrosarcoma. We report a rare presentation of this lesion arising from the posterior aspect of the right elbow in a 38-year-old woman, diagnosed on biopsy. Recognizing the key similarities and differences between florid RPO, and other similar appearing disorders discussed in this paper, can prevent the pitfall of misdiagnosis and unnecessary aggressive surgery.