Nora’s lesion of Upper and Lower limb bones- A series of 8 cases

Introduction: Bizarre parosteal osteochondromatous proliferation (BPOP) presents as painless bony swelling and also known as Nora’s lesion. It is a benign surface osteocartilaginous lesion. This condition is seen most commonly in hands followed by feet. Long bone involvement is rare.  Materials and Methods: This is a retrospective study of the patients who had visited the orthopedic OPD of our institute from January 2011 to December 2019. The diagnosis of BPOP was made by radiological evaluation and confirmed by histopathological evaluation. Results: There were 8 cases included in this study. Out of them, 4 cases (50%) were female, and 4 cases (50%) male. The age distribution of patients was 14 years to 36 years. The duration of the history of present illness was 6 months to 3 years. There were 6 cases (75%) of the upper limb and 2 cases (25%) of the lower limb. 4 cases (50%) had a history of trauma. All cases were operated on after pre-operative evaluation and the excisional biopsy specimen was sent for histopathological evaluation for confirmation. On follow up 2 cases (25%) had recurrence for which re-operation was done. Conclusion: BPOP involving long bones is exceedingly rare. The local recurrence rate after surgical resection of the lesion is high. En bloc resection of the lesion along with decortication of the underlying cortical bone was done to reduce the possibility of recurrence. Two patients in our series had a recurrence for which re-operation was done. Keywords: Nora’s lesion, BPOP, Bony swelling, Osteochondramatous proliferation.