BRAF V600E mutations are characteristic for papillary craniopharyngioma and may coexist with CTNNB1-mutated adamantinomatous craniopharyngioma

Excerpt

Craniopharyngiomas are epithelial, sellar tumours comprising two subtypes: adamantinomatous (aCP) and papillary (pCP). aCPs contain mutations in CTNNB1, encoding β-catenin: a component of the adherens junction and mediator of Wnt signalling. Reported frequency of CTNNB1 mutations varies widely (16–100 %) [6, 7]. Recently, it was reported that pCPs contain BRAF p.V600E mutations in 95 % of cases [2] and that CTNNB1 and BRAF mutations are mutually exclusive and specific to tumour subtype. We examined the relationship between mutation in CTNNB1 and BRAF and subcellular location of β-catenin in a series of 37 craniopharyngiomas. The region of BRAF exon 15 containing codon 600 was sequenced, as was exon 3 of CTNNB1. Immunohistochemistry (IHC) for β-catenin was used to examine its subcellular location and an antibody specific for the BRAF V600E mutation (clone VE1) was used to complement the sequencing findings in all aCP and pCPs. Methods are reported in Online Resource 1. …