Fig. 7

A 32 year-old-female presenting with a hoarse voice. Axial fused (a) and unfused (b) PET/CT images of the skull base showing a hypometabolic soft tissue mass centered on the left jugular foramen with smooth osseous expansion suggestive of schwannoma of cranial nerve IX, X or XI which all exit the skull base through the jugular foramen. Axial fused (c) and unfused (d) PET/CT images at the level of the glottis show no 18F-FDG uptake in the left vocal cord (blue arrow) with compensatory increased activity in the right vocal cord, consistent with laryngoscopy proven left vocal cord paralysis due to tumor involvement of left CN X and its recurrent laryngeal branch. Asymmetric atrophy of the left sternomastoid and trapezius muscles is consistent with chronic denervation due to tumor involvement of the left cranial nerve XI (spinal accessory nerve) (red arrows). Axial CT scan of the skull base with bone window settings (e) and axial post-contrast fat-suppressed T1 MRI (f) at the same level show the enhancing left cranial nerve IX/X/XI mass pathologically proven to be a schwannoma. g Coronal MIP image of a 50-year-old male with HIV presenting with worsening right facial weakness and pathologically proven squamous cell carcinoma of the neck, with perineural tumor invasion along the jugular foramen (not shown), showing right shoulder drooping compared to the left one (red line), secondary to atrophy of the right trapezius and sternomastoid muscles, confirmingCN XI involvement. Also note the bulky hypermetabolic cervical adenopathy (arrow) in the rightneck involving lymph node levels 1 through 4 consistent with metastatic lymph nodes