Secondary malignant neoplasm of lymphoid tissue

When a malignant neoplasm of lymphoid tissue metastasizes beyond the lymph nodes, a code from categories C81-C85 with a final character identifying “extranodal and solid organ sites” should be assigned rather than a code for the secondary neoplasm of the affected solid organ.

For example, for metastasis of diffuse large B-cell lymphoma to the lung, brain and left adrenal gland, assign code C83.398, Diffuse large B-cell lymphoma of other extranodal and solid organ sites.