Pituitary adenoma: Encyclopedia II - Pituitary adenoma - Diagnosis

Pituitary adenoma - Diagnosis

The diagnosis is generally entertained either on the basis of visual difficulties arising from the compression of the optic nerve by the tumor, or on the basis of manifestations of excess hormone secretion: the specifics depend on the type of hormone. Tumors which cause visual difficulty are likely to be macroadenomas greater than 10 mm in diameter; tumors less than 10 mm are microadenomas.

The most common secretory pituitary tumor is the prolactinoma, which can cause galactorrhea, hypogonadism, amenorrhea, infertility, and impotence. GH-secreting tumors cause acromegaly (gigantism). Corticotrophic adenomas cause Cushing's disease. TSH-secreting adenomas can, rarely, cause hyperthyroidism. Tumors which secrete LH, FSH or TSH most often don't cause symptoms because of that hormone secretion. Some tumors secrete more than one hormone, the most common combination being GH and prolactin.

Prolactinomas are frequently diagnosed during pregnancy, when the hormone progesterone increases the tumor's growth rate.

Headaches may be present.

The diagnosis is confirmed by testing hormone levels, and by radiographic imaging of the pituitary (for example, by CT scan or MRI).

Adapted from the Wikipedia article "Diagnosis", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki