(4) Cancer described as "metastatic to" a site should be interpreted as a
secondary of that site. Also, assign the appropriate code for the primary malignant
neoplasm of specified site if the primary site is identified or code to the unspecified site
(as stated in e(3) above).
EXAMPLE: Metastatic carcinoma to lung.
Code to : Secondary neoplasm of lung (197.) and primary malignant neoplasm of
unspecified site (199.1).
EXAMPLE: Metastatic carcinoma from liver to lung.
Code to : Primary malignant neoplasm of liver (155.) and secondary neoplasm of lung
(5) If two or more sites are stated in the diagnosis and all are qualified as
metastatic code as for primary site unknown, code the stated sites as secondary
neoplasm of those sites.
EXAMPLE: Metastatic melanoma of lung and liver.
Code to : Secondary neoplasm of lung (197.) and liver (197.7) and primary malignant
melanoma of unspecified site (172.9).
EXAMPLE: Metastatic carcinoma of brain and lung.
Code to : Secondary neoplasm of brain (198.3) and lung (197.) and primary
carcinoma of unspecified site (199.1).
(6) If only one site is stated in the diagnosis and this is qualified as metastatic,
proceed as follows:
(a) Code as for primary site unknown; however, if this code is 199. or
199.1, follow rule (6)(b) below.
(b) If the code arrived at in (6)(a) above is 199. or 199.1, code instead as
for primary malignant neoplasm of the stated site except for the following sites, which
should be coded to the secondary neoplasm of that site.
spinal cord (198.3)
lymph nodes (196.9)
site classifiable to 195
Also assign the appropriate code for primary or secondary malignant neoplasm
of specified or unspecified site, depending on the diagnostic statement being