[Spontaneous regression of an aneurysmal bone cyst of the vertebrae after partial excision. Bibliographic review].

A case of a lumbar aneurysmal bone cyst is presented in a 5 year-9 month old girl. The characteristics of this tumor are described, specifically in the spinal area, with particular reference to the diagnostic and therapeutic difficulties referred, taking into account the existing bibliography. The partial resection has been curative, as it has been frequently written about in publication worldwide and which suggest that surgery does not have to be aggressive in unapproachable cases and that radiotherapy is unnecessary.