Vertebral Pneumatocyst-A Systematic Review.

Background: Intraosseous pneumatocyst refers to gas-filled cystic lesions inside bone. Whereas ilium and sacrum are the commonest locations for pneumatocysts, vertebral pneumatocysts are rare. Various theories have been proposed to explain the etiopathogenesis of vertebral pneumatocysts and the most widely accepted theory is the extension of air from intervertebral disc or joint spaces into the pneumatocyst cavity. The aim of this systematic review was to study all the cases of vertebral pneumatocyst reported in the literature to understand this rare disease and its clinical importance.

Methods: A comprehensive search of the PubMed, Embase, and Scopus databases was performed to retrieve case reports and case series describing the cases of pneumatocyst.

Results: A total of 61 cases of incidentally reported vertebral pneumatocyst were included in the systematic review. The mean age of the patients was 57.82 ± 10.2 years (range, 31-89 years). The mean size of the pneumatocysts was 8.67 ± 4.18 mm (range, 2-20 mm).

Conclusions: The prevalence of pneumatocyst increased with increasing age, with most of the reported patients belonging to the 50-70 years age-group. Most of these patients have large pneumatocysts with degenerative changes in spine. Another less common subset of young patients with small pneumatocysts without associated degenerative changes has also been described. Pneumatocysts were most common in the cervical spine, with C5 being the most commonly affected vertebra. Most of the pneumatocysts remain stable in size on follow-up, although 3 cases of enlarging pneumatocyst have also been reported. An enlarging pneumatocyst should be closely followed up, although its benign nature has been reported in the literature.