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
