EXAMPLE: Metastatic lung cancer.
Code to : Primary malignant neoplasm of lung (162.9), and secondary malignant
neoplasm, unspecified site 199.1.
EXAMPLE: Metastatic cancer of brain.
Code to : Secondary neoplasm of brain (198.3) and primary malignant neoplasm of
unspecified site (199.1).
(7) If no site is stated in the diagnosis, but the morphological type is qualified as
"metastatic," code as primary site unknown.
EXAMPLE: Metastatic apocrine adenocarcinoma.
Code to : Primary malignant apocrine adenocarcinoma of unspecified site (173.9), and
secondary malignant neoplasm, unspecified site 199.1.
f. When Neoplasm is the Underlying Cause of Death.
(1) Code to primary site when known or as "primary site unknown" when
(2) Categories 196, 197, and 198 are not to be used for underlying cause of
death coding. Secondary neoplasm of specified sites, of unspecified site, or without
mention of primary site, will be coded as "primary site unknown."
EXAMPLE: Metastatic carcinoma to colon.
Code to : Morphological type involved (carcinoma - 199.1) for underlying cause of
a. The patient is admitted with a suspected malignant neoplasm:
(1) If confirmed, the neoplasm is sequenced first.
(2) If not confirmed, list as admission for suspected neoplasm.
b. The patient is admitted with a confirmed malignant neoplasm:
(1) If the neoplasm is treated (e.g., surgically), the neoplasm is sequenced first.
(2) If only a condition caused by the neoplasm is treated, the condition (not the
neoplasm) is sequenced first (e.g., dehydration). An exception to this is if the condition
is coded in Chapter 16 of ICD-9-CM.