Genomic Alterations in Sporadic Pituitary Tumors

Pituitary tumors are undergoing a transformation in histopathologic and molecular classification, coincident with the continued refinement of increasingly powerful methods of genomic annotation and discovery. We highlight novel genomic alterations identified in pituitary adenomas and craniopharyngiomas and discuss their clinical implications.

Sporadic pituitary adenomas are associated with relatively few recurrent somatic mutations. Recurrent mutations occur largely in subsets of hormone-producing tumors, including GNAS and GPR101 in somatotroph adenomas and USP8 in corticotroph adenomas. Additionally, they manifest with a dichotomous signature of copy number alterations, ranging from almost none to widespread genome instability, while microduplication of chromosome Xq26.3, containing the GNAS gene, defines X-linked acrogigantism. Papillary craniopharyngiomas are defined by BRAF ^V600E mutations while β-catenin alterations characterize adamantinomatous craniopharyngiomas. Genomic annotation of pituitary tumors is defining increasing subsets of neuroendocrine adenohypophyseal tumors and craniopharyngiomas, offering rationale-based pharmacologic targets and potential biomarkers for clinical outcome.