LEGENDS
Figure 1: CT scan images on axial (A) and coronal (B) planes. Partially
cystic, expansive lesion infiltrates and erodes the petrous bone,
extending with its more solid component, above the mastoid region,
inferiorly along the upper portion of the latero-cervical region (A and
B). The lesion extends intracranially, budging within the adjacent
portion of middle and posterior fossa. (C) Axial 3D T2 weighted-imaging
better highlights the inhomogeneous cystic content and the infiltration
of the posterior part of the bony labyrinth. (D) CT scan axial imaging
showing the removal of the mastoid part of the lesion, with air within
the surgical cavity (arrowhead).
Figure 2. Serial MR axial fat-saturated images T2 images at the
mid-level of the bony labyrinth (upper row) and slightly inferiorly
(lower row), performed 1 (A, B), 4 (C, D) and 7 (E, F) months after
surgery. The images clearly shows the significant volumetric reduction
of the lesion (arrowheads) with ossification of the petrous bone and the
inner ear bony structure (dotted line in A and C).