Bizarre Parosteal Osteochondromatous Proliferation of Long Bones: Two New Cases and Literature Study

Abstract

In research on tumors of mesenchymal origin, although the type localized in the short, tubular bones has been evaluated in detail, there have been no reports to date regarding the clinical, radiological and treatment characteristics of the type localized in the long bones. In this study, Nora’s lesions localized in the long bones were investigated in terms of their characteristics and behavior. An extensive literature review was performed using PubMed, MEDLINE (1983 - 2012) and Google Scholar. Search terms included ‘‘bizarre parosteal osteochondromatous proliferation’’ (BPOP) and ‘‘Nora’s lesion’’. The literature search yielded 88 articles and a total of 43 patients. The median age of the cases was 26 years. BPOP occurred with equal frequency in men and women. The most frequent sites of involvement were the femur (25%) and the ulna (23%). Plain radiographs of 20 cases were available, but only a small number of cases had CTs (n = 11) and MRIs (n = 12) performed. It was determined that 66% of the lesions led to cortical changes, while 23.5% led to medullary invasion or soft tissue infiltration. As to treatments, “simple excision” (intralesional) was performed on seven lesions, marginal resection was performed in nine patients, wide resection was performed in two patients, “shark-bite” surgery was performed in one patient and “shave excision” was performed in one patient. The mean follow-up period was 30.9 months. Local recurrence rate was 18.75%. Clinically and in terms of radiological images, we believe that this lesion observed in the long bones consists of four phases: stages I, II, III and IV. We believe this type of lesion demonstrates no spontaneous recovery, and that it is a progressive lesion involving cortical destruction and medullary infiltration. As such, we consider marginal resection to be the appropriate technique for treating this lesion. J Med Cases. 2014;5(6):315-325 doi: https://doi.org/10.14740/jmc1624w