Abstract

INTRODUCTION and OBJECTIVE: Also known as Nora lesion, bizarre parosteal osteochondromatous proliferation (BPOP) is a benign exophytic lesion originated from the bone. In this study, we aimed to evaluate four patients with Nora lesion who were evaluated between 2010 and 2018, and to review current information through a brief literature screening. MATERIAL and METHODS: A total of four patients with a mean age of 32 ± 24 years (26-37 years) including 2 female and 2 male patients were included in the study. Patients’ time to diagnosis and symptoms, clinical findings, mass size, MRI findings, surgical treatments, treatment outcomes and complications were investigated. RESULTS: Marginal excision was made to all the patients. The most common mass localization was the long bones of the forearm. Recurrence was developed in one patient at postoperative 24th month, and underwent relapse resection. The remaining three patients did not develop relapse or complications at follow-up. DİSCUSSION and CONCLUSION: Bizarre parosteal osteochondromatous proliferation is a rare bone lesion, which may be localized in many different part of the body, has a benign character, but may be encountered with frequent recurrence. A careful marginal excision to performed with a good preoperative planning is the most crucial key in prevention of relapses.