Changes

[[Image:Chromophobe adenoma.jpg|right|thumb|150px|<small><center>'''Chromophobe Adenoma'''. Courtesy of A. Jefferies</center></small>]]

[[Image:Chromophobe adenoma.jpg|right|thumb|150px|<small><center>'''Chromophobe Adenoma'''. Courtesy of A. Jefferies</center></small>]]

80-85% cases of Cushings disease show bilateral adrenal hyperplasia due to excess stimuation by ACTH.  There is a failure of the negative feedback mechanism at the level of the pituitary and so ACTH is produced in an unregulated fashion. This is thought to occur due to a functional chromophobe cell (Produces ACTH and MSH) neoplasia, although visible macroadenomas are only found in 10-15% cases with this aetiology.  Most cases are therefore thought to be microadenomas and may be visualised by histopathological staining of the pituitary.

80-85% cases of Cushings disease show bilateral adrenal hyperplasia due to excess stimuation by ACTH.  There is a failure of the negative feedback mechanism at the level of the pituitary and so ACTH is produced in an unregulated fashion. This is thought to occur due to a functional chromophobe cell (Produces ACTH and MSH) neoplasia, although visible macroadenomas are only found in 10-15% cases with this aetiology.  Most cases are therefore thought to be microadenomas and may be visualised by histopathological staining of the pituitary.

[[Image:Nodular hyperplasia.jpg|left|thumb|150px|<small><center>'''Adrenal Nodular Hyperplasia'''. Courtesy of A. Jefferies</center></small>]]

[[Image:Nodular hyperplasia.jpg|right|thumb|150px|<small><center>'''Adrenal Nodular Hyperplasia'''. Courtesy of A. Jefferies</center></small>]]

Grossly the adrenals have an irregular surface with protruding nodules of cortical tissue; the hyperplased zona fasciculata cells.

Grossly the adrenals have an irregular surface with protruding nodules of cortical tissue; the hyperplased zona fasciculata cells.