Petrous Apex Mucocele: A Case Report and Literature Review

Background A petrous apex mucocele is a rare benign cystic lesion that can present with symptoms due to pressure on surrounding structures, including the internal carotid artery, Meckel’s cave and the fifth and sixth cranial nerves, as well as the cavernous sinus region and inner ear. Methods A 36-year-old male presented with 8 months of diplopia when looking to the right, a right-sided temporoparietal headache, and paresthesia in the right half of his face. An MRI revealed a 26 × 32 × 37 mm lesion in the right petrous apex. The lesion’s signal characteristics were most consistent with a mucocele. We performed an endoscopic endonasal transclival marsupialization and created a wide drainage opening, which we supported by inserting a stent containing mometasone furoate. Results The postoperative course was marked by transient arterial hypertension, which required antihypertensive treatment. Postoperative imaging studies revealed no intracranial complications and confirmed that the drainage pathway remained patent. Conclusion In the differential diagnosis of lesions in the medial portion of the petrous apex, a mucocele should be considered. In appropriately selected cases, endoscopic endonasal marsupialization can be an effective option. To maintain postoperative patency of the drainage pathway, an implant containing mometasone furoate may also be used.