Craniopharyngioma is a type of epithelial neoplasm that develops in the
sellar region, a feature that distinguishes these tumors from other glial or neuronal
lesions in the same location. Although the etiology of craniopharyngioma has not yet
been confirmed, this type of tumor is generally thought to derive from the epithelial
remnants of the craniopharyngeal duct that eventually forms part of the
adenohypophysis. In this chapter, we address the pathological classification of
craniopharyngioma and its molecular aspects. craniopharyngiomas can be divided into
two subtypes: adamantinomatous craniopharyngioma (ACP) and squamous papillary
craniopharyngioma (SPCP). ACP is more common (90% of all craniopharyngiomas),
particularly among children. ACP features various types of epithelial characteristics
such as peripheral palisades, stellate reticulum, whorl-like array cells, wet keratin, and
cholesterol clefts. SPCP tumors are found almost exclusively in adults and generally
present as solid masses comprised histologically of sheets of well-differentiated
squamous epithelial cells, with prominent papillae composed of squamous epithelial
cells that grow around fibrovascular cores. ACp 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%).
Recently, it was reported that pCps contain BRAF p.V600e mutations in 95% of cases
and that CTNNB1 and BRAF mutations are mutually exclusive and specific to tumour
subtype.
Keywords: Beta-catenin, BRAF p.V600e, Craniopharyngioma, Molecular
mechanism, Pathway, WNT.
