Genetic Testing
Genetic testing was performed on the excised tissue in 43.5% (10/23) of
cases. BRAF tissue testing was performed in 5 patients and was
negative in all (5/5). In 1 patient with Spitzoid melanoma,
immunohistochemistry stains showed that the large atypical cells were
diffusely and strongly positive for SOX-10 and S-100 and
negative for p 16, CD34 , desmin and SALL-withretention of BAP1 expression throughout the tumor. Another 2 patients
with Spitzoid melanoma also had retained BAP1 . One patient with
melanoma in situ underwent a chromosomal microarray, p 53
sequencing and deletion/duplication testing that were all normal.BRCA2 mutation was negative for a patient with melanoma of
unspecified subtype. Two patients were tested with the Castle
diagnostics gene expression profile assay; one was classified as stage
2B with the highest risk of recurrence and/or metastasis within the next
5 years while the other patient was classified as stage 2A with an
increased risk of recurrence or metastasis within the next 5 years. The
patient with the stage 2A classification was also tested via the Invitae
Multi-Cancer Panel with resulting variants of unknown significance (VUS)
in AIP , CASR , and MSH3 and no mutations inBRAF .