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(
A
) Postcontrast T1-weighted MRI 2.8 years before presenting to our center demonstrating no evidence of lesion. (
B
) Recent postcontrast T1-weighted (
C
) T2-weighted fast spin echo, and (
D
) thin slice heavily T2-weighted MRI demonstrated an expansile mass involving the right meatal, labyrinthine, geniculate, and proximal tympanic facial nerve.
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However, recent imaging revealed avid enhancement of the right geniculate ganglion with widening of the labyrinthine segment and the geniculate ganglion ( Fig. 1 ).
(
A
) Coronal and (
B
) axial temporal bone computed tomography demonstrating expansion of the labyrinthine and geniculate segments of the fallopian canal with honeycomb stippling (intralesional spindle-like calcifications) and a cochlear fistula.
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Computed tomography (CT) demonstrated an expansile lytic process with honeycomb stippling involving the right facial nerve centered on the labyrinthine segment and involving the geniculate ganglion ( Fig. 2 ).
(
A
) Histological sections demonstrate disorganized nerve fascicles, which also involved peripheral ganglia (hematoxylin and eosin; x100 magnification). (
B
) Longitudinal and cross-sections of the disorganized nerve fascicles, suggesting variably density of the axons (hematoxylin and eosin; x100 magnification). (
C
) Neurofilament highlights the axonal disorganization in the longitudinal section and demonstrates axonal aggregates in the cross-sections, suggestive of axonal clustering (x100 magnification).
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No associated cellular proliferation or abnormal blood vessels were identified ( Fig. 3 ).