[Corticotropic hypophyseal microadenomas detected by immunohistochemical methods].

Study of two autoptic cases of corticotrophic pituitary adenomas (in a 47-year-old man and a 60-year-old woman) proved that 1. very small pituitary adenomas with mature corticotrophic cells can produce a serious Cushing syndrome without any lesion of sella turcica or compression of optic chiasm. General situation of the patient with central type Cushing syndrome may then exclude any surgical intervention on the pituitary; 2. Nelson syndrome need not develop after bilateral adrenalectomy and adequate substitution; 3. very small adenomas are preferably studied by immunohistochemistry, bigger ones are sampled for electron microscopy with advantage; 4. immunohistology of ACTH is feasible in autoptic material supposing the autolysis is not advanced.