Ectopic pituitary adenoma occurring in the interpeduncular cistern

Abstract

Intracranial ectopic pituitary adenoma occurs most frequently in the suprasellar cistern, usually in continuity with the pituitary stalk. Such tumors probably originate from cells of the pars tuberalis located above the diaphragma sellae or from aberrant anterior pituitary cells of the pituitary stalk. The authors report the case of a 37-year-old woman with Cushing's syndrome caused by an ectopic pituitary adenoma of unique location: the tumor was separate form the pituitary stalk and confined within the interpeduncular cistern. After surgical removal of the tumor, continued improvement in the patient's laboratory results and disappearance of her endocrine symptoms strongly indicated the absence of adenoma cells in the pituitary gland or stalk. The tumor in the present case appears to have arisen from aberrant pituitary cells that were present in the leptomeninges of the basal surface of the hypothalamus.

An Aberrant ACTH-producing Ectopic Pituitary Adenoma in the Sphenoid Sinus

“…Regarding Cushing's disease due to corticotropinomas, the ratio of circulating ACTH (pg/ml by IRMA) to cortisol (mg/dl) was found to be 2.4 to 2.6 or 5.1 to 5.5 in cases of microadenoma or macroadenoma, respectively [30]. Based on this finding, the present case [7.25 to 12.1] and the other three [8.08, 12.0 and 8.0] out of 16 EAPA cases documented (see Table 1) were shown to have relatively high ratios of ACTH (pg/ml) to cortisol (mg/dl) com- pared to common Cushing's diseases, although these three cases, unlike our case, were reported to have completely overt Cushingoid features including moon face, truncal obesity, skin striae, pigmentation and atrophy, cervicodorsal hump, hypertension and diabetes mellitus [4,13,15]. Although the discrepancy of clinical symptoms and endocrine profile could be related to the individual sensitivity to cortisol, it is also possible that an aberrant less-active ACTH molecule exists in the plasma of these EAPA patients [31].…”

“…1A and B). On her endocrine examinations, plasma ACTH level was markedly increased (196 to 280 pg/ml; normal, 9-52) but the serum cortisol level was not remarkable (23 to 27 mg/dl; normal [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. Daily secretion of ACTH and cortisol lacked the normal circadian rhythm (Fig.…”

Intracavernous Sinus Ectopic Adrenocorticotropin-Secreting Tumours Causing Therapeutic Failure in Transsphenoidal Surgery for Cushing's Disease

“…It has been reported that pituitary adenomas rarely occur at a site in close proximity to but not in direct contact with the pituitary gland. The sites of these ectopic parasellar pituitary adenomas include the suprasellar region [1,7,10,14,15,20,21,29,30], the sphenoid sinus [11,13,27] and other intracranial regions [17,28]. Interestingly, a relatively large proportion of these ectopic pituitary adenomas consists of ACTH-secreting adenomas [1,7,11,17,20,21,27,28,29].…”

Disfunção hormonal em lesões não hipofisárias das regiões selar e periselar

“…Ele prejudica o transporte da dopamina para os lactotrofos normais e resulta em hiperprolactinemia leve a moderada (< 200 ng/ml) [25][26][27] . Entretanto, Smith e Laws colocaram em dúvida o efeito de secção da haste e hipotetizaram que o fator mais provável fosse o aumento da pressão intra-selar 26 .…”