Intraosseous pneumatocyst is a rare benign condition, commonly seen in iliac bone or sacrum.
6) Gas in the pneumatocyst may disappear spontaneously, and the cyst might change to a fluid-filled cyst.
Intraosseous pneumatocyst should be differentiated from bone neoplasms and osteomyelitis by its characteristic imaging findings.
Given that the MR signal characteristics of pneumatocysts are not pathognomonic for a gas-containing lesion, the characteristic CT findings have proven to be the most useful in diagnosing a pneumatocyst.
When encountered on MR imaging, the pneumatocyst presents a potentially confusing appearance and one that can be indistinguishable from a more ominous lesion such as a blastic metastasis.
Pneumatocyst is another form of intraosseous gas collection that has been reported in the ilium, sacrum, and vertebrae (3-5) and yet is rarely found in other bones.
An anteroposterior radiograph of the cervical region revealed a right cervical rib and a pneumatocyst of the proximal epiphysis (Fig.