Figure legends:
Figure 1 . Tumor imaging findings
(a–d) A tumor measuring approximately 1.5 cm can be visualized in the
left cerebellopontine angle (red arrow).
(a) Contrast enhancement effect was observed only in the anterior area
on gadolinium-enhanced, T1-weighted images. (b) Diffusion-weighted
images showed diffusion limitation. (c–f) The tumor appeared to be
continuous with the left border of the pons. (d) The right trigeminal
nerve (green arrowhead) is compressed by the tumor.
(g and h) The tumor morphologically consists mainly of large nodular
structures with well-defined borders, and low-to-moderate cell densities
within the nodules. Between the nodules, cells with a high N/C ratio and
round nuclei with densely packed hyperchromatic chromatin are observed.
(i) Silver staining reveals reticular fibers in the dark background
surrounding the bright nodules. (j) The MIB-1 index is low at the
nodules, but high at 68% around the nodules.
Figure 2. DNA sequencing
(a) DNA sequencing of normal tissue confirms the germline pathogenic
variant of PTEN . (b) Copy number analysis of the tumor reveals
copy number neutral loss of heterozygosity of chromosome 10q, wherePTEN is located.