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| Pituitary Adenoma | ||
| Etiology •Unknown | ||
| Pathogenesis •The role of oncogenes, tumor suppressor gene and growth factors in producing pituitary adenomas is under investigation. •Oversecretion of hypothalamic regulating hormones may also play a role., | ||
| Epidemiology •Pituitary adenomas are seen in about 20% of autopsies but make up about 10% of symptomatic CNS tumors. •They are seen most commonly in adults and any hormone may be secreted. •The most common types of secreting tumors are the growth hormone and prolactin secreting tumors with FSH and LH secreting tumors being rare. •Tumors that are devoid of hormones and cause symptoms by destroying normal pituitary cells are also common. • Pituitary adenomas used to be classified by the color of their cytoplasm, acidophilic, chromophobe and basophilic, but these colors give no clue as to which hormone is being secreted. | ||
| General Gross Description •Pituitary adenomas may be micro or macro. •Microadenomas appear as small nodules in the normal sized pituitary, whereas, macroadenomas enlarge the pituitary. •They are grey tan and relatively firm and may extend into the suprasellar space and invade various structures and compress the optic chiasm. •Examples: | ||
| General Microscopic Description Microscopically, pituitary adenomas are made up of uniform, polygonal cells with uniform oval to round nuclei. •Cytoplasm may be acidophilic, pale pink or basophilic but usually is of only one color in a single adenoma. •Examples: | ||
| Clinical Correlation The symptoms of a pituitary adenoma depends on what hormone it secrets. •Increased growth hormone causes giantism in children and acromegaly in adults. •Prolactin secretion in males can produce infertility and enlargement of the breasts. In females it may produce no symptoms. •ACTH secreting tumors produce Cushings syndrome. •Other hormone oversecretion is rare. •If a tumor extends above the sella turcica it may compress the optic chiasm causing a bitemporal hemianopsia or compress the hypothalamus. | ||
| References • Poirer J et.al. Manual of basic neuropathology. Philadelphia: Saunders, 1990, pp. 43. • Cotran RS, Kumar V, Robbins SL: Robbins Pathologic Basis of Disease. 5th ed. Philadelphia, W.B. Saunders, 1994, pp. 1116-1117. Please be patient during transfer. Medline will open in a new window. To return, close the Medline Window Pituitary Adenoma
| Synopsis by: Margaret Grunnet M.D. (T91000M82700)[355]
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