Health

What is the significance of silent and plurihormonal pituitary tumors? The diagnosis of a silent or a plurihormonal adenoma is important because of their typical aggressive behavior, high degrees of invasiveness, and high rates of recurrence. Patients with these tumors are typically refractory to standard treatments and often require repeat surgical resections and/or radiation treatments. …

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What are the types of nonfunctioning adenomas? Nonfunctional pituitary tumors are subtyped by immunohistochemical staining for the various pituitary hormones and the pituitary-specific transcription factors that delineate their pituitary cell lineages. NFAs constitute a heterogeneous group of tumors, including the following: Gonadotrophs the vast majority of cases [80%]—stain for LH-beta, FSH-beta, and/or alpha subunit and/or …

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Nonfunctional pituitary adenomas comprise an estimated ≈ 30% of pituitary tumors. NFAs typically occur in patients in the fifth to sixth decades of life and have a slight male predominance. The clinical spectrum of NFAs varies from being asymptomatic and detected incidentally (< 10% of adenomas), to presenting with large tumors with mass effects. Delayed …

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What is the differential diagnosis of a sellar mass? The differential diagnosis of sellar masses is broad and includes (in relative order of frequency): pituitary adenomas, rest cell tumors (e.g., Rathke’s cleft cysts, craniopharyngiomas), arachnoid cysts, mesenchymal/stromal tumors (e.g., meningiomas, chordomas), neuronal/paraneuronal tumors (e.g., gangliocytomas, neuroblastomas), primary and secondary hypophysitis, tumors of the posterior pituitary …

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How are pituitary adenomas classified? Pituitary adenomas are characterized as follows: Cell of origin: Gonadotroph, lactotroph, somatotroph, corticotroph, or thyrotroph-derived as determined by immunohistochemical staining for the pituitary hormones and the transcription factors that determine pituitary cell lineages (e.g., T-Pit = corticotrophs; SF-1 = gonadotrophs; and Pit-1 = thyrotrophs, somatotrophs, and lactotroph cells). Size: Microadenomas < 1 …

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How common are pituitary adenomas Pituitary adenomas are benign, monoclonal neoplasms of anterior pituitary cells. A pituitary incidentaloma is a previously unsuspected pituitary lesion that is detected on radiography performed for an unrelated reason. The prevalence of adenomas varies by detection method, including: ≈ 10% by autopsy series and ≈ 20% in radiographic series. Most …

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What is carcinoid crisis? Carcinoid crisis is a life-threatening episode of hypotension, flushing, and bronchospasm that is triggered most often by tumor manipulation or anesthesia and less commonly by chemotherapy, hepatic artery embolization, or radionuclide therapy. It can also be provoked by the administration of adrenergic agents, such as epinephrine and sympathomimetic amines, or monoamine …

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