Bizarre Parosteal Osteochondromatous Proliferation causing angular deformities: A Case Report

There have been fewer than 150 cases of Bizarre Parosteal Osteochondromatous proliferation (Nora Lesions) reported in the literature to date and no significant reports on angular deformities caused by this lesion. Nora's lesion can easily be misdiagnosed as osteochondroma or chondrosarcoma and therefore inappropriately managed. Although this condition classically appears in the second or third decade, we present to you a three year old boy who presented with multiple bony swellings over the hand and feet that caused an angular deformity of the involved digits. In the case report we have detailed the angular deformities and its treatment outcome.

A three year old boy presented with valgus deformity of middle finger of right upper limb with an associated ulnar bony swelling at the level of middle phalanx which was noticed two years before and was progressing rapidly since last three months. On physical examination the swellings were found to be bony hard, midly tender and found to have been causing an angulare deformity of the digits. The initial suspicion was of osteochondromatous lesion however the excision biopsy showed the lesion to be of the rare entity of bizarre parosteal osteochondromatous proliferation. 1 year follow up showed no progression of angular deformity of the operated digits.

Bizarre osteochondromatous proliferation is an entity that can rarely present in children which needs to be identified and tackled early to prevent the onset of deformities. Almost all cases warrant surgical intervention and the type of excision varies with the type of lesion.