Bizarre Parosteal Osteochondromatous Proliferation (Nora Lesion) in Upper and Lower Limbs: A Report of Three Cases and Review of Literature

INTRODUCTION: Bizarre parosteal osteochondromatous proliferation (BPOP) is a rare bone pathology affecting small bones of hand and feet. This benign lesion needs to be distinguished from many malignant bone tumors as it poses a diagnostic dilemma due to its clinical, radiological, and histological picture. We report three cases of BPOP affecting the hand and foot. CASE 1: A 21-year-old gentleman presented with painful swelling in the long finger of the right hand. A plain radiograph showed a radio dense mass which was later excised and diagnosis confirmed in histopathology. There was no recurrence in 2 years of follow-up. CASE 2: A 5-year-old boy presented with painful swelling over the right ankle with no history of antecedent trauma. Following radiological evaluation, the patient was successfully treated with excision. CASE 3: A 35-year-old lady presented with a painful swelling on the dorsal aspect of her hand which was gradually increasing in size. After radiological evaluation, the patient was successfully treated with excision and lesion confirmed to be BPOP on histological examination. She was symptom free without recurrence in up to 2 years of follow-up. CONCLUSION: Nora’s lesion is a rare pathology requiring high index of suspicion. Excision is the recommended mode of treatment. All our cases responded well with excision with immediate pain relief following surgery and no recurrence in up to 2 years of follow-up.