PITUITARY-GLAND AND SELLA TURCICA IN HUMAN TRISOMY-18 FETUSES

The purpose of this study was to elucidate the phenotypic conditions i n the sella turcica/pituitary gland complex in human trisomy 18 fetuse s. Fourteen human fetuses with gestational ages from 12 to 39 weeks we re included in the study, Normal fetuses at corresponding ages were us ed as controls. Whole body and special radiographic examination was un dertaken before the midsagittal cranial base block, including the pitu itary gland, was excised and analyzed histologically and immunohistoch emically (keratin wide spectrum [KWS], thyroid-stimulating hormone [TS H], and neurophysin [Nph]). In all trisomy 18 fetuses, TSH-positive ad enopituitary tissue was present in the sella and in greater or lesser amounts pharyngeally. The neurohypophysis was Nph-positive and located normally in the sella turcica. The adenohypophyseal tissue reacted ei ther KWS-faint or KWS-negative, whereas KWS-positive reaction occurs i n normal fetuses. This circumstance might suggest an altered cytoskele tal structure of the surface ectoderm in the pituitary placode in tris omy 18. The sella turcica was malformed in all the fetuses. Very broad craniopharyngeal canals were observed in some of the fetuses. Because endocrine disorders occur in many congenital malformations, it is ess ential in future studies to chart the sella turcica/pituitary gland re gion systematically in different genotypes. (C) 1998 Wiley-Liss, Inc.