Oncology & Hematology Coding Alert

Question: I-m new to coding and unfamiliar with neoplasm terminology. Specifically, what are the definitions of -malignant- vs. -in situ,- etc.? I thought the only thing that mattered was -malignant- or -benign.-


Arkansas Subscriber
Answer: The neoplasm table in ICD-9 does classify neoplasms into two main categories (malignant and benign), but within each of these are various subcategories.

The three subcategories for malignant neoplasms are as follows:

Primary: A primary malignancy is one arising from the cells found where the surgeon biopsied the neoplasm.

For example, if a female patient has a breast lump in the lower-inner quadrant that is malignant and composed of cancer cells from the area of excision (as opposed to cancer cells that originated elsewhere and spread to the breast), you should code for a primary malignancy (174.3).

Secondary: You should use these codes when the neoplasm is the result of metastasis and forms a new focus of malignancy elsewhere, such as the lymph nodes, liver, lungs or brain or when the primary cancer has invaded adjacent structures.

For example, if a surgeon removes a lump from the chest wall beneath the previous mastectomy and the pathology report indicates that the lump is a secondary malignancy with the breast as the origin, you should report a secondary neoplasm code (198.8x).

In situ: In situ describes malignancies confined to the origin site without invasion of neighboring tissues, although they can grow large enough to cause major problems. In some cases, however--such as those involving the breast (233.0), bladder (233.7) and cervix (233.1), for instance--there is no guarantee that removing the mass will totally eradicate the cancer.

If pathology does not find evidence of cancer, you should not report a malignant ICD-9 code. Instead, choose from the following three categories:

Benign: Benign neoplasms do not contain any cancer cells. For example, for a fibroadenoma of the breast, which does not spread, report a benign neoplasm (217). Benign neoplasms may return after removal, but they are typically noninvasive.

Uncertain behavior: If the pathology report returns with indications of atypia or dysplasia, the neoplasm is in transition from benign to malignant. If the process continues and the mass is left untreated, the neoplasm could eventually become malignant. For example, benign adenomatous polyps are at high risk for becoming malignant if they remain untreated.

Do not confuse -uncertain- with -unspecified.- A pathologist makes the -uncertain- determination based on analysis.

If the pathologist labels the neoplasm uncertain, you shouldn't use an unspecified diagnosis because -unspecified- implies that the surgeon's documentation didn't indicate the lesion's type.

Unspecified: Generally, the use of -unspecified- codes means that there is insufficient information in the medical record for the coder to determine the correct code assignment. The answers for You Be the Coder and Reader Questions were [...]