Pneumatocisto intra-ósseo: relato de caso * Intraosseous pneumatocyst: case report

This study aims to present the case of a rare, albeit benign lesion, the intraosseous pneumatocyst. The case report was based on an occasional radiographic finding from a 13-year-old patient who presented with low back pain. Pneumatocysts are rare bone lesions that contain air within, which are more frequent at the iliac and sacral bones, adjacent to the sacroiliac joints. Different from this present case, the highest incidence is around 20 to 50 years of age. Despite imprecise timing (weeks, months, or years), the exchange of air content by fluid or granulation tissue is expected, with no possibilities of lesion aggravation or malignancy transformation, thus advocating its non-invasive treatment. The treatment choice was the observation, with periodic imaging controls, as advocated by the literature. The tomographic follow-up of this present case after 18 months showed lesion filling by soft-tissue density and surrounding calcified material. Intraosseous pneumatocyst is a benign lesion, and the CT features along with the lack of specific symptoms are important data for the diagnosis, thus avoiding unnecessary invasive procedures.