2025 ICD-10-CM code C79
(Active) Effective Date: N/A Neoplasms - Malignant neoplasms of ill-defined, other secondary and unspecified sites 2: Neoplasms Feed
Secondary malignant neoplasm of other and unspecified sites.
The medical necessity for the workup and treatment of secondary malignant neoplasm is established by the confirmed diagnosis of metastatic cancer. The specific treatment approach will depend on the primary cancer type, the location and extent of metastases, the patient's overall health, and treatment goals.
A patient with secondary malignant neoplasm of other and unspecified sites may experience symptoms depending on the organ affected. Providers diagnose the disease based on history, signs and symptoms, and physical examination. Laboratory tests and imaging studies depend on the site of secondary cancer. Secondary cancers are usually difficult to treat, but the primary aim of treatment is to control the symptoms and prevent further metastasis, to improve the quality of life. Treatment depends on the severity, the patient’s previous treatment, general health, and disease progression. If the secondary cancer is resectable, surgical management may help. Other treatments include chemotherapy and radiation therapy.
In simple words: Secondary malignant neoplasm means cancer that has spread from where it started to other parts of the body. This code is used when the doctor knows the cancer has spread but doesn't specify exactly where, or when the specific location isn't covered by another code.
Secondary malignant neoplasm refers to the spread of cancer cells from a primary site through blood vessels or lymphatic vessels. This category includes other sites affected by secondary malignant neoplasm that the provider identifies which are not represented by another code, as well as the sites which the provider does not specifically name.
Example 1: A patient with a history of lung cancer presents with new bone pain. Imaging reveals metastatic lesions in the spine, consistent with secondary malignant neoplasm.The primary site is known (lung), but since there is no specific code for secondary malignancy of the spine from lung cancer, C79 is used., A patient with a history of breast cancer presents with generalized weakness and fatigue. Blood tests reveal multiple organ dysfunction, suggestive of widespread metastases.The exact locations of the metastases are not determined, so C79 is used to indicate secondary malignant neoplasm of unspecified sites., A patient with a previous melanoma resection presents with several enlarged lymph nodes. Biopsy confirms metastatic melanoma. While a more specific code for the lymph node involvement may exist, if documentation only indicates unspecified lymph node involvement C79 may be used in this case.
Documentation should clearly state the diagnosis of secondary malignant neoplasm and, if known, the primary site of the cancer. If the specific site(s) of metastasis is known, it should be documented. Any associated signs, symptoms, and diagnostic test results should also be recorded.
- Specialties:Oncology, Hematology, Internal Medicine, various surgical specialties (depending on site of metastasis)
- Place of Service:Inpatient Hospital, Outpatient Hospital, Physician's Office, etc. (depending on the clinical scenario and the specific treatment being provided)