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Case

A previously healthy 6-year-old girl reports a two-day history of right ear pain. Her parents confirm complaints of headache over the prior 4 days and decreased appetite together with emesis the day prior. They deny a prior history of acute otitis media, but past history includes fever and right-sided hearing loss. She had no recent ear drainage or complaints of disequilibrium.

Examination of the ears reveals protrusion of the right pinna with postauricular tenderness to palpation. Otoscopy reveals a mucoid middle ear effusion. On physical exam, the cranial nerves are intact. Total leukocyte count was 20 × 10 ⁹ /L (3.4–10.8 × 10 ⁹ /L). Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) of the temporal bones were obtained for further workup.

CT imaging revealed a mass lesion in the right sigmoid fossa associated with destructive osseous changes in the right temporal bone and an aggressive periostitis/new bone formation manifesting a “sun-burst” appearance ( Fig. 1 ). Brain MRI showed a heterogeneous mass in the right sigmoid fossa and an adjacent temporal bone lesion associated with solid enhancing soft tissue along the petrous ridge that involved the bone and epidural space ( Figs. 2 and 3 ). Diffusion weighted imaging (DWI) demonstrated restricted diffusion compatible with hypercellularity in solid components of the lesion ( Fig. 4 ).

Axial CT image through the temporal bones displayed in bone algorithm. Deficiency of the right sigmoid plate (small arrow) and an aggressive periostitis (large arrow) is seen.

Axial T2-weighted MRI showing a heterogeneous mass in the sigmoid fossa (small arrows) and adjacent soft tissue lesion extending along the petrous ridge (large arrows). Abnormal soft tissue thickening is present in the extracranial soft tissues (arrowheads).

Axial post-contrast T1-weighted MRI depicting a mass in the right sigmoid fossa (small arrows) and adjacent solid enhancing soft tissue mass along the right petrous ridge involving the bone and epidural space (large arrows). Again seen is extension in the scalp (arrowheads).

Axial DWI image demonstrates heterogeneous, mixed restricted (bright signal, arrows) and facilitated (dark signal) diffusion.

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What is the diagnosis?

A. Ewing sarcoma

B. Mastoiditis with extra-temporal bone spread

C. Langerhans cell histiocytosis

D. Neuroblastoma metastasis

2

What is the diagnosis?

A. Ewing sarcoma

B. Mastoiditis with extra-temporal bone spread

C. Langerhans cell histiocytosis

D. Neuroblastoma metastasis