Chemotherapy-Induced Regression of an Adrenocorticotropin-Secreting Pituitary Carcinoma Accompanied by Secondary Adrenal Insufficiency
Figure 4
(a) H and E. The diffuse pattern of basophilic cells seen in the 2010 lesion is characteristic of corticotroph adenoma. There is mild nuclear pleomorphism. (b) ACTH stain shows positive cytoplasmic staining, confirming the diagnosis of corticotroph adenoma. (c) Ki-67, a proliferation marker, is increased to 5–7%. Values over 3% are noted as a potential indicator of more aggressive behavior but alone do not allow diagnosis as an atypical adenoma by World Health Organization criteria.
