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PITUITARY GLANDAnatomy/Physiology | Pituitary/Adrenal Axis | Hypothalamus/Pituitary Axis | Diseases/Syndromes The Hypothalamus/Pituitary AxisProblems in Evaluation
Hormones of the Neurohypophysis: ADH, Oxytocin Diagnosis of Hypothalamic and Pituitary DiseaseDiagnosis of these diseases is based on clinical and laboratory data. Radiologic data has to be interpreted carefully due to individual variability in bone structures such as the Sella Turcica. MRI with 1.5mm collimation is essential in current work up of intracranial lesions as cause of endocrinologic disease.Craniopharyngiomas (70%) and meningiomas (30%) may calcify and produce stippling on x-ray. Craniopharyngiomas, are the most common tumors of hypophysis in children and young adults. Microscopic adenomas may not alter the sella. Visual field exam may reveal compression of optic chiasm. Work up Hyper-secreting adenomas are the most common dysfunction of the pituitary in adults. Other than hypersecretion, they cause sellar enlargement and visual impairment. Hypopituitarism is present in less than 20% of these cases. PRL is the hormone most frequently increased in adenomas. Hypogonadism therefore is one of the most frequent findings secondary to elevated PRL, GH, ACTH and cortisol.Empty Sella Syndrome: Subarachnoid space fills sella space, and pituitary flattens. May also occur as secondary to destructive lesions such as Sheehan’s Syndrome or radiation therapy. Hypothalamic DysfunctionHypothalamic tumors are the most common cause for dysfunctions of the hypothalamic-pituitary axis. This dysfunction occurs as a result of craniopharyngiomas, for the most part. It occurs mostly in children. Craniopharyngiomas present mainly as growth retardation (50%) and with decreased GH (70%). Other signs of hypothalamic dysfunction are Diabetes Insipidus disorders of consciousness and appetite. Digital Legends for Labs Home Updated June 13, 2005
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