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Elderly Woman with Diplopia
This case features an elderly woman presenting with diplopia, ultimately diagnosed with a malignant peripheral nerve sheath tumor (MPNST) of the left Meckel’s cave.
Imaging overview:
Axial T2 fat-saturated imaging demonstrates a left Meckel’s cave mass with surrounding edema at the level of the left hemi-pons. Coronal fat-saturated post-contrast imaging shows the mass extending into the left foramen ovale and along V3, with central necrosis. Axial post-contrast FSPGR imaging confirms enhancement of the mass with central necrotic change, and medial extension toward the left hemi-pons.
Clinical insight:
Malignant peripheral nerve sheath tumors are rare, aggressive neoplasms that can arise along cranial nerves, including the trigeminal nerve. When occurring in Meckel’s cave, they may present with cranial nerve symptoms such as diplopia or facial numbness. Key imaging features include irregular margins, invasion into surrounding bone and soft tissues, central necrosis, and associated edema. MPNST is associated with neurofibromatosis type 1 (NF-1), and this association should be considered in any patient presenting with an aggressive nerve sheath lesion. Post-contrast imaging is essential for characterizing the extent of the tumor and identifying necrosis.
Case courtesy of Keerthi Arani, MD, UPMC.