I have a patient with a diagnosis of well-differentiated neuroendocrine tumor (carcinoid). In ICD-10, carcinoid is broken down into either benign or malignant, and the default for neuroendocrine is benign with a subterm of malignant poorly differentiated. Well-differentiated is not a subterm. I would like to know how others code this. Since "well-differentiated" is not a subterm of either carcinoid or neuroendocrine tumor, I’m going to code it as benign. Thoughts?

Thanks!
Melody