Neuroendocrine tumors of the pituitary gland: Modern diagnostic approach

Pituitary neuroendocrine tumors (PitNET) are originating from adenohypophyseal cells. Although benign, PitNETs sometimes exhibit aggressive biological behavior that was the inspiration for change of old and traditional name "pituitary adenomas". Current standard in PitNET diagnostics, according to WHO criteria, is immunohistochemistry, with application antibodies adenohypophysis hormones transcription factors TPIT (T-box family member TBX19), PIT1 (pituitary factor 1) SF-1 (steroidogenic factor-1) which, line differentiation assessed. In there somatotroph, lactotroph thyrotroph tumors. Somatotroph lineage produce growth hormone (GH). The defines following subtypes somatotroph tumors: densely granulated sparsely tumor. Lactotroph most common pituitary gland. estrogen receptor a (ERa) play key role their genesis. There two tumors, differentiated by type prolactine (PRL) staining pattern. Thyrotroph expess both GATA binding protein 3 (GATA3), can show variable positivity thyroid-stimulating (TSH). Beside these three main tumor types lineage, mixed mamosomatotroph tumor, acifophilic "stem cell" mature immature plurihormonal Corticotroph express TPIT, adrenocorticotrophic (ACTH). They be granulated. Rare subtype corticotroph behavior, Crooke cell Gonadotroph SF1 differentiation, they follicle-stimulating (FSH) luteinizing (LH). Null-cell no distinct do not any factors. With use factors, diagnosed through elimination, number tented decrease.