Oncology & Hematology Coding Alert

Question: How do I document a neuroendocrine tumor (carcinoid) that the provider has documented as well-differentiated? The only entry I can find in ICD-10-CM is for a malignant poorly differentiated neuroendocrine tumor. Does that mean that a well-differentiated tumor is benign? If so, I can find no ICD-10-CM entry for that.

AAPC Forum Participant

Answer: Your association of a well-differentiated tumor as being benign and a poorly differentiated one as malignant is basically correct. Well-differentiated cells “look more like healthy cells,” while poorly differentiated cells “look less like healthy cells,” according to the American Society of Clinical Oncology (Source: www.cancer.net/cancer-types/neuroendocrine-tumors/grades).

You are also correct in saying that there is a code for a poorly differentiated neuroendocrine tumor: C7A.1 (Malignant poorly differentiated neuroendocrine tumors). Well-differentiated tumors, as you say, do not have their own codes, but there are codes for benign neuroendocrine tumors in the D3A.- (Benign neuroendocrine tumors) code group.

The codes are broken down by anatomic site, with codes for sites in the small intestine (D3A.01-); the appendix, large intestine, and rectum (D3A.02-); other sites (D32.09-); an unspecified site (D3A.00); and sites not otherwise specified (D3A.8, Other benign neuroendocrine tumors). So, depending on your provider’s documentation, you should be able to pick the correct code for the well-differentiated neuroendocrine tumor from this group.