Bizarre parosteal osteochondromatous proliferation or Nora’s lesion affecting the extremities: A concise update

Abstract

The bizarre parosteal osteochondromatous proliferation or Nora’s lesion is an unusual clinical entity that presents with localized swelling and pain. The characteristic radiological appearance includes a cluster of variably calcified lesions adjacent to a particular bone. However, it does not necessarily have direct continuity with its medullary region. The etiopathogenesis of this disorder is not yet fully understood. Various other lesions require careful exclusion and the use of advanced imaging modalities to supplement the diagnosis. The final diagnosis of the lesion, however, is based on the histopathological basis. However, these lesions are reported as sporadic reports or small series in the literature and are also discovered in areas other than the common locations in hands and feet. The recent research aims to throw more advanced knowledge into their causation, including genetic etiology. The symptomatic lesions may require excision for clinical relief, but recurrence is not uncommon. The future research, and preferably multi-center collaboration, is required for more insight into their comprehensive nature and clinical spectrum. A brief and crisp update of the articles published in the past 10 years describing bizarre parosteal oseochondromatous proliferation in the extremities is presented here for educational purposes for orthopedists and generalists alike.