Secondary jaw aneurysmal bone cyst ( JABC ) – a possible misnomer? A review of literature on secondary JABC s, their pathogenesis and oncogenesis

Context Aneurysmal bone cysts are rare pseudocysts, commonly seen in long bones and vertebral column. Although a well described and reported lesion, many misconceptions still prevail regarding their etiopathogenesis. Many of the reported cases of jaw aneurysmal bone cysts ( JABC ) present with another bone pathology. Aims The purpose of this review was to evaluate the incidence of neoplastic lesions occurring simultaneously with a JABC (in contrast to primary JABC s). Any pathogenetic and oncogenetic association between primary and secondary jaw ABC s has been reviewed and discussed. Settings and Design A methodical narrative review of literature was performed, given the incidence of mostly case reports on this topic. Methods and Material A methodical electronic search of Pubmed, Pubmed Central, Medline and Cochrane databases was performed for reported cases of JABC . These articles were analysed and segregated into primary and secondary ABC and, if secondary, the lesion it concurrently occurred with. Another search was conducted to yield articles discussing the cytopathogenetic and oncogenetic origins of ABC s. Results and Conclusions About 15% of the ABC s reported were of secondary nature. Amongst the associated lesions, cement‐ossifying fibroma and ossifying fibroma were the most common, followed by fibrous dysplasia and central giant cell granuloma. No ABC s were associated with metastatic changes. The search for histopathogenesis pointed to a specific cytogenetic abnormality as the origin of primary ABC s, with USP 6 as its main oncogene and spindle cell as the neoplastic cell, unlike with secondary ABC s, suggesting that they are distinct pathological processes.