Pseudocyst of Temporal Bone and Posterior Cranial Fossa Caused by Cholesterol Granuloma

Abstract

Accurate preoperative diagnosis of temporal bone lesion is critical because the surgical approaches used for this region are different depending upon the specific disease process involved. While CT and MID have improved the accuracy of preoperative diagnosis of temporal bone pathology, these imaging studies are most helpful when used in conjuction with one another. This case showed a pseudocyst of lhe temporal bone and posterior cranial fossa caused by a blockage of aditus ad antrum due to cholesterol granuloma. The patient was a 33-year-old man with a right-sided temporo-occipital headache. Computed tomography revealed a mass involving the temporal bone and posterior cranial fossa with central bony density. On MRI, the mass showed isosignal intensity with respect to the brain on Tl-weighted image, hyperintense signal to the brain on T2-weighted image, peripheral enhancement on gadolinum enhanced image. Histologically, the mass showed a cholesterol cleft, multinucleated giant cells and a fibrotic capsule without endothelial lining. The patient had no postoperative difficulty and was discharged without problems.