Ki-67/MIB1 labeling index of 4% or more, and p53 positive. In its malignancy, adrenocortical carcinoma is unlike most tumours of the adrenal cortex, which are benign (adenomas) and only occasionally cause Cushing's syndrome. References External links Rare cancers Endocrine neoplasia Endocrine-related cutaneous conditions Adrenal gland disorders