Oncology & Hematology Coding Alert

Check to see if you’re correctly coding these common situations.

Coding lung cancer, like all other forms of cancer, requires understanding nuances. From the basics of understanding whether lung cancer is coded by type or site, to knowing when to apply a personal history of other malignant neoplasm code once the cancer has entered remission, there’s a lot to take in.

That’s why lung cancer coding has developed its own set of myths over the years. Here are four we’ve dispelled to keep your cancer coding clean and compliant.

Know How Cancer Dx Codes Break Down

Myth 1: There are two different diagnosis codes for non-small cell lung cancer (NSCL) and small cell lung cancer (SCLC).

Reality: There are four main types of lung cancer, categorized by how the cancerous cells appear under a microscope:

• Small cell lung cancer (SCLC), also called oat cell cancer
• Squamous cell carcinoma, also called epidermoid carcinoma
• Adenocarcinoma
• Large cell carcinoma, which includes cells that are not diagnosed as squamous, adenocarcinoma, or SCLC

Any cancer other than SCLC is regarded as NSCL. However, ICD-10-CM codes for lung cancer do not differentiate between SCLC or NSCL. Instead, they are broken down by primary anatomic site or metastatic anatomic site.

That means you would use the appropriate code from the C34 (Malignant neoplasm of bronchus and lung) codes for primary

lung cancer and C78.0- (Secondary malignant neoplasm of lung) for metastatic lung cancer, regardless of whether the cancer is SCLC or NSCL. For specificity, you’ll the appropriate 4th and 5th digits to the codes to document the site of the cancer.

Know How to Code Primary and Secondary Dx

Myth 2: When a provider documents that the patient has a primary neoplasm of the right lower lobe with metastasis to the left lung, you report both the left and right lung cancer under the primary code.

Reality: ICD-9 Coding Clinic Vol. 27, No. 3 (2010) addressed a similar question in which the patient had been diagnosed with cancer of the left lower lobe and metastasis to the right lung, peritoneum, and liver. The Coding Clinic stated proper coding would include a code for the primary cancer in the left lung and a code for the metastatic cancer in the right lung.

That means you would report this scenario with two codes, such as C34.31 (Malignant neoplasm of lower lobe, right bronchus or lung) and C78.02 (Secondary malignant neoplasm of left lung).

Why? “The specific reason for the encounter will drive principal (or first-listed) diagnosis code selection. If a patient presents due to malignancy with treatment aimed at the primary site, the primary site is the principal diagnosis. Alternatively, if treatment is for the secondary site only, the secondary site is the principal diagnosis. However, if a patient presents for chemotherapy, immunotherapy, or radiation therapy, you will then turn to Z51.- (Encounter for other aftercare and medical care) as the principal diagnosis,” says Leah Fuller, CPC, COC, senior consultant at Pinnacle Enterprise Risk Consulting Services, Charlotte, North Carolina.

Caution: Don’t assume that the presence of a second neoplasm in the same organ system as a primary neoplasm means that you have both primary and secondary neoplasms. A patient may have two primary neoplasms in the same organ system. Let the documentation guide your choice.

Know How to Code Lung Mass

Myth 3: If a patient with a history of cancer elsewhere in the body has a lung mass, and that mass cannot be confirmed as being malignant, you should code the mass as metastatic using a C78.- code.

Reality: In a scenario like this, you cannot code the mass as either primary or metastatic, as the biopsy cannot confirm it is a malignant neoplasm. Instead, you would code the lung mass with R91.8 (Other nonspecific abnormal finding of lung field). Given that the patient has a history of cancer, you should also use the appropriate code from Z85 (Personal history of malignant neoplasm) as a secondary diagnosis.

Know Your Surveillance Code Options

Myth 4: When a patient presents for surveillance of their lung cancer, and the cancer is not being actively treated because it has been excised or eradicated, you use Z12.2 (Encounter for screening for malignant neoplasm of respiratory organs).

Reality: While it may be tempting to use a screening code in scenarios like this, Z12.2 is not the correct way to document cancer surveillance when the cancer is no longer active and the patient is not receiving treatment for it.

In fact, “the correct code for this diagnostic encounter is Z08 (Encounter for follow-up examination after completed treatment for malignant neoplasm). You may also report Z85.118 (Personal history of other malignant neoplasm of bronchus and lung) as a secondary diagnosis,” advises Sheri Poe Bernard, CPC, of Poe Bernard Consulting in Salt Lake City.

Why? ICD-10-CM guideline I.C.2.d busts this myth. It says, “when a primary malignancy has been previously excised or eradicated from its site and there is no further treatment directed to that site and there is no evidence of any existing primary malignancy at that site, a code from category Z85, Personal history of malignant neoplasm, should be used to indicate the former site of the malignancy.” This tells you Z12.2 would not be correct to use in a lung cancer surveillance encounter because the neoplasm is not present and treatment has been completed. In other words, because you can apply Z85.118 to this scenario, Z08 then becomes the primary diagnosis code for surveillance scenarios when the patient’s cancer is no longer being treated.