Apart from pituitary adenomas, there are ectopic sources of ACTH like small cell lung cancer, and in these cases the excess ACTH is coming from somewhere other than the pituitary.

除了垂体腺瘤，ACTH也有异位来源，比如小细胞肺癌；在这种情况下，垂体以外的部位分泌过多的ACTH。

It can be exogenous, meaning drug-related, or endogenous, meaning that it's from an adrenal tumor or excess ACTH from a pituitary adenomas, in which case it's called Cushing disease or from an ectopic site like small cell lung cancer.

它可以是外源性，也就是药物相关；或内源性，也就是由肾上腺肿瘤或由垂体腺瘤分泌过多ACTH造成，这种情况下叫做库欣病，或是源于异位分泌，比如小细胞肺癌。