Source 1: ICD-O-3
Behavior Code--Bladder/Lymphoma: Should the "in situ" designation on a bladder primary's pathology report be ignored that states a diagnosis of "in situ lymphoma"?
Ignore the in situ designation. You cannot assign an in situ behavior code to a lymphoma primary. The term or designation of "in situ" is limited to solid tumors; carcinoma and/or cancer.