title: Hyperplasia-adenoma sequence in pituitary tumorigenesis related to aryl hydrocarbon receptor interacting protein gene mutation.
abstract: Mutations of the aryl hydrocarbon receptor interacting protein (AIP) gene are associated with pituitary adenomas that usually occur as familial isolated pituitary adenomas (FIPA). Detailed pathological and tumor genetic data on AIP mutation-related pituitary adenomas are not sufficient. Non-identical twin females presented as adolescents to the emergency department with severe progressive headache caused by large pituitary macroadenomas require emergency neurosurgery; one patient had incipient pituitary apoplexy. Post-surgically, the patients were found to have silent somatotrope adenomas on pathological examination. Furthermore, the light microscopic, immunohistochemical, and electron microscopic studies demonstrated tumors of virtually identical characteristics. The adenomas were accompanied by multiple areas of pituitary hyperplasia, which stained positively for GH, indicating somatotrope hyperplasia. Genetic analyses of the FIPA kindred revealed a novel E216X mutation of the AIP gene, which was present in both the affected patients and the unaffected father. Molecular analysis of surgical specimens revealed loss of heterozygosity (LOH) in the adenoma but showed that LOH was not present in the hyperplastic pituitary tissue from either patient. AIP immunostaining confirmed normal staining in the hyperplastic tissue and decreased staining in the adenoma in the tumors from both patients. These results demonstrate that patients with AIP germline mutation can present with silent somatotrope pituitary adenomas. The finding of somatotrope hyperplasia unaccompanied by AIP LOH suggests that LOH at the AIP locus might be a late event in a potential progression from hyperplastic to adenomatous tissue.
authors: Unit of Neuropathology, INSERM U984 Laboratory of Glial Plasticity, Centre Hospitalier Sainte Anne, University of Paris Descartes, 1 Rue Cabanis, 75014 Paris, France. chiaravilla@hotmail.it
authors: Chiara
authors: C
authors: Villa
authors: Maria Stefania
authors: MS
authors: Lagonigro
authors: Flavia
authors: F
authors: Magri
authors: Maria
authors: M
authors: Koziak
authors: Marie-Lise
authors: ML
authors: Jaffrain-Rea
authors: Raja
authors: R
authors: Brauner
authors: Jerome
authors: J
authors: Bouligand
authors: Marie Pierre
authors: MP
authors: Junier
authors: Federico
authors: F
authors: Di Rocco
authors: Christian
authors: C
authors: Sainte-Rose
authors: Albert
authors: A
authors: Beckers
authors: François Xavier
authors: FX
authors: Roux
authors: Adrian F
authors: AF
authors: Daly
authors: Luca
authors: L
authors: Chiovato
mesh_terms: D000236:Adenoma / Q000150:complications / Q000175:diagnosis / Q000235:genetics*; D000293:Adolescent; D001483:Base Sequence; D018450:Disease Progression; D004200:Diseases in Twins / Q000175:diagnosis / Q000235:genetics; D005260:Female; D049912:Growth Hormone-Secreting Pituitary Adenoma / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology; D006801:Humans; D006965:Hyperplasia; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics*; D019656:Loss of Heterozygosity / Q000502:physiology; D008297:Male; D009154:Mutation / Q000502:physiology; D010375:Pedigree; D010902:Pituitary Gland / Q000473:pathology*
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; C103265:aryl hydrocarbon receptor-interacting protein