Chapter 2 – Neoplasms
Coding neoplasms requires an understanding of the pathophysiology of neoplasms, which in turn means gaining knowledge of tumor behavior and morphological type for a given anatomical site.
Chapter 2, “Neoplasms” (C00-D49), contains broad groups of neoplasms listed by body site and behavior of neoplasm. All neoplasms are located in this chapter, whether functionally active or not. In some cases, an additional code from Chapter 4 “Endocrine, Nutritional and Metabolic Diseases,” may be used to report any functional activity.
Half of all men and one-third of all women in the United States will develop cancer during their lifetimes. The term “neoplasm” refers to a new or abnormal growth. Malignant neoplasms are characterized by uncontrolled growth and spread of abnormal cells. Excluding certain skin and in situ carcinomas, more than a million new cases of cancer are diagnosed in the U.S. each year. Cancer is the second-leading cause of death in the United States. Improvements in detection, diagnosis, and treatment have increased the survival rate of many types of cancer. It is estimated that 68% of all people diagnosed with cancer will be alive 5 years after being diagnosed.2
Neoplasia can be broken into “neo” meaning “new,” and “plasia,” meaning “tissue” or “cells.” Neoplasm, or tumor, refers to a new or abnormal cell growth that is uncontrolled and progressive.
Another common term used in medicine is cancer. The National Cancer Institute identifies several main types of cancer3, including the following:
| Cancer | Description |
| Carcinoma | A cancer that begins in the skin or in tissues that line or cover internal organs |
| Sarcoma | A cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue |
| Leukemia | A cancer that starts in blood-forming tissue such as the bone marrow and causes large numbers of abnormal blood cells to be produced and enter the blood |
| Lymphoma and multiple myeloma | Cancers that begin in the cells of the immune system |
| Central nervous system cancers | Cancers that begin in the tissues of the brain and spinal cord |
Other terms associated with neoplasms are morphology and behavior. The behavioral type relates to how the neoplasm acts; the morphological, or histological, type relates to the type of tissue affected.
Cells in the body that are similar in structure tend to group together, forming tissue. Morphology refers to the form and structure of the tumor cells and tissue, and classifies the tissue by its origin. Morphological or histological type is the type of tissue in which the neoplasm originates. Some examples of morphological types and the tissue’s origin are as follows:
| Morphological Type | Origin |
| Osteosarcoma | Bone |
| Adenoma | Glandular structures |
| Squamous cell carcinoma | Skin |
| Leukemia | Blood-forming tissue |
In the case of malignant tumors, the morphology of the tumor often determines the following:
- Expected rate of growth
- Metastasis
- Degree of severity
- Treatment protocol
There is no single test that can determine a definitive diagnosis or treatment plan for a malignant neoplasm. A physical exam that detects lumps, nodules, or tumors could be followed by screening laboratory tests, endoscopy, x-rays, ultrasounds, or magnetic resonance imaging (MRI).
Some of the more common treatments of malignant neoplasms include the following:
| Treatment | Description |
| Chemotherapy | Treatment of cancer with an antineoplastic drug |
| Radiation therapy | Cancer treatment with a form of energy released in particles or waves. In high doses, radiation destroys cells or keeps them from multiplying. The goal is to kill cancer cells and shrink tumors. |
| Surgery | Eradication or removal of the diseased tissue |
| Immunotherapy | Boosting of the patient’s immune system |
| Photodynamic therapy (PDT) | Use of a photosensitizing drug and light to form a chemical that kills the cancer cells |
| Anti-angiogenesis | Use of drugs and other substances to prevent the tumors from making new blood vessels |
| Hyperthermia | Use of high heat energy to destroy (ablate) the tumor cells |
| Bone marrow and peripheral blood stem cell transplants | Restoration of the destroyed stem cells used to make bone marrow |
| Targeted therapy | Use of drugs or other substances to more precisely identify and attack cancer cells, usually while doing little damage to normal cells4 |
There are very specific indexing and sequencing guidelines for the correct reporting of neoplasms. The correct sequencing of the principal diagnosis will depend on the appropriate assignment of the coding guidelines. In general, if the reason for admission is the neoplasm, the code for that condition will be listed first. If primary and secondary neoplasm sites are present, the circumstances resulting in the admission will affect the sequencing. Physician documentation of a history of a particular neoplasm or its spread (metastasis) to another area of the body can be difficult to interpret.
Use of Section I.C.2.a-r of the ICD-10-CM Official Guidelines for Coding and Reporting contains general and specific coding guidelines related to Chapter 2. These specific guidelines and guidance on coding and sequencing neoplasms include conditions such as anemia, dehydration, previously excised malignancies, and chemotherapy.
To identify the morphology for the majority of Chapter 2 codes that do not include the histological type, assign a separate morphology code. In a few cases, such as for malignant melanoma and certain neuroendocrine tumors, the morphology is included in the codes.
The International Classification of Diseases for Oncology (ICD-O), not ICD-10-CM, contains the morphology codes.