Enlarging cervical vertebral pneumatocyst - A case report.

Intraosseous pneumatocyst refers to gas-filled cystic lesions inside bone. Vertebral pneumatocysts are rare and most have been described to remain static over time. We report a rare case of an enlarging spinal pneumatocyst. A 58-year-old male patient with cervical ossified posterior longitudinal ligament with two cervical vertebral pneumatocysts (C4 and C5). The C5 cyst (9.91 × 5.9 × 4.3 mm) was larger than the C4. MRI was suggestive of compression at C4-5 and C5-6 level. Repeat imaging done eight months later showed an increase in the size of the C5 pneumatocyst (12.41 × 7.6 × 6.3 mm). In view of the enlarging pneumatocyst, patient underwent C5 corpectomy. Histopathological examination of the cyst wall revealed fibro-collagenous tissue with histiocytes and foreign body giant cells confirming the benign nature of the disease. This case highlights the importance of radiological follow up of a pneumatocyst.