General guidelines

Chapter 2 of the ICD-10-CM contains the codes for most benign and all malignant neoplasms. Certain benign neoplasms, such as prostatic adenomas, may be found in the specific body system chapters. To properly code a neoplasm it is necessary to determine from the record if the neoplasm is benign, in-situ, malignant, or of uncertain histologic behavior. If malignant, any secondary (metastatic) sites should also be determined.

Primary malignant neoplasms overlapping site boundaries
A primary malignant neoplasm that overlaps two or more contiguous (next to each other) sites should be classified to the subcategory/code .8 ('overlapping lesion'), unless the combination is specifically indexed elsewhere. For multiple neoplasms of the same site that are not contiguous such as tumors in different quadrants of the same breast, codes for each site should be assigned.

Malignant neoplasm of ectopic tissue
Malignant neoplasms of ectopic tissue are to be coded to the site of origin mentioned, e.g., ectopic pancreatic malignant neoplasms involving the stomach are coded to pancreas, unspecified (C25.9).

The neoplasm table in the Alphabetic Index should be referenced first. However, if the histological term is documented, that term should be referenced first, rather than going immediately to the Neoplasm Table, in order to determine which column in the Neoplasm Table is appropriate. For example, if the documentation indicates "adenoma," refer to the term in the Alphabetic Index to review the entries under this term and the instructional note to "see also neoplasm, by site, benign." The table provides the proper code based on the type of neoplasm and the site. It is important to select the proper column in the table that corresponds to the type of neoplasm. The Tabular List should then be referenced to verify that the correct code has been selected from the table and that a more specific site code does not exist.

See Section I.C.21. Factors influencing health status and contact with health services, Status, for information regarding Z15.0, codes for genetic susceptibility to cancer.

a. Admission/Encounter for treatment of primary site

If the malignancy is chiefly responsible for occasioning the patient admission/encounter and treatment is directed at the primary site, designate the primary malignancy as the principal/first-listed diagnosis.

The only exception to this guideline is if the administration of chemotherapy, immunotherapy or external beam radiation therapy is chiefly responsible for occasioning the admission/encounter. In that case, assign the appropriate Z51.-- code as the first-listed or principal diagnosis, and the underlying diagnosis or problem for which the service is being performed as a secondary diagnosis.

b. Admission/Encounter for treatment of secondary site

When a patient is admitted because of a primary neoplasm with metastasis and treatment is directed toward the secondary site only, the secondary neoplasm is designated as the principal diagnosis even though the primary malignancy is still present.

c. Coding and sequencing of complications

Coding and sequencing of complications associated with the malignancies or with the therapy thereof are subject to the following guidelines:

1) Anemia associated with malignancy

When admission/encounter is for management of an anemia associated with the malignancy, and the treatment is only for anemia, the appropriate code for the malignancy is sequenced as the principal or first-listed diagnosis followed by the appropriate code for the anemia (such as code D63.0, Anemia in neoplastic disease).

2) Anemia associated with chemotherapy, immunotherapy and radiation therapy

When the admission/encounter is for management of an anemia associated with an adverse effect of the administration of chemotherapy or immunotherapy and the only treatment is for the anemia, the anemia code is sequenced first followed by the appropriate codes for the neoplasm and the adverse effect (T45.1X5, Adverse effect of antineoplastic and immunosuppressive drugs). When the admission/encounter is for management of an anemia associated with an adverse effect of radiotherapy, the anemia code should be sequenced first, followed by the appropriate neoplasm code and code Y84.2, Radiological procedure and radiotherapy as the cause of abnormal reaction of the patient, or of later complication, without mention of misadventure at the time of the procedure.

3) Management of dehydration due to the malignancy

When the admission/encounter is for management of dehydration due to the malignancy and only the dehydration is being treated (intravenous rehydration), the dehydration is sequenced first, followed by the code(s) for the malignancy.

4) Treatment of a complication resulting from a surgical procedure

When the admission/encounter is for treatment of a complication resulting from a surgical procedure, designate the complication as the principal or first-listed diagnosis if treatment is directed at resolving the complication.

d. Primary malignancy previously excised

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. Any mention of extension, invasion, or metastasis to another site is coded as a secondary malignant neoplasm to that site. The secondary site may be the principal or first-listed with the Z85 code used as a secondary code.

e. Admissions/Encounters involving chemotherapy, immunotherapy and radiation therapy

1) Episode of care involves surgical removal of neoplasm

When an episode of care involves the surgical removal of a neoplasm, primary or secondary site, followed by adjunct chemotherapy or radiation treatment during the same episode of care, the code for the neoplasm should be assigned as principal or first-listed diagnosis.

2) Patient admission/encounter solely for administration of chemotherapy, immunotherapy and radiation therapy

If a patient admission/encounter is solely for the administration of chemotherapy, immunotherapy or radiation therapy assign code Z51.0, Encounter for antineoplastic radiation therapy, or Z51.11, Encounter for antineoplastic chemotherapy, or Z51.12, Encounter for antineoplastic immunotherapy as the first-listed or principal diagnosis. If a patient receives more than one of these therapies during the same admission more than one of these codes may be assigned, in any sequence. The malignancy for which the therapy is being administered should be assigned as a secondary diagnosis.

3) Patient admitted for radiation therapy, chemotherapy or immunotherapy and develops complications

When a patient is admitted for the purpose of radiotherapy, immunotherapy or chemotherapy and develops complications such as uncontrolled nausea and vomiting or dehydration, the principal or first-listed diagnosis is Z51.0, Encounter for antineoplastic radiation therapy, or Z51.11, Encounter for antineoplastic chemotherapy, or Z51.12, Encounter for antineoplastic immunotherapy followed by any codes for the complications.

f. Admission/encounter to determine extent of malignancy

When the reason for admission/encounter is to determine the extent of the malignancy, or for a procedure such as paracentesis or thoracentesis, the primary malignancy or appropriate metastatic site is designated as the principal or first-listed diagnosis, even though chemotherapy or radiotherapy is administered.

g. Symptoms, signs, and abnormal findings listed in Chapter 18 associated with neoplasms

Symptoms, signs, and ill-defined conditions listed in Chapter 18 characteristic of, or associated with, an existing primary or secondary site malignancy cannot be used to replace the malignancy as principal or first-listed diagnosis, regardless of the number of admissions or encounters for treatment and care of the neoplasm. See section I.C.21. Factors influencing health status and contact with health services, Encounter for prophylactic organ removal.

g. Symptoms, signs, and abnormal findings listed in Chapter 18 associated with neoplasms

See Section I.C.6. for information on coding admission/encounter for pain control/management.

i. Malignancy in two or more noncontiguous sites

A patient may have more than one malignant tumor in the same organ. These tumors may represent different primaries or metastatic disease, depending on the site. Should the documentation be unclear, the provider should be queried as to the status of each tumor so that the correct codes can be assigned.

j. Disseminated malignant neoplasm, unspecified

Code C80.0, Disseminated malignant neoplasm, unspecified, is for use only in those cases where the patient has advanced metastatic disease and no known primary or secondary sites are specified. It should not be used in place of assigning codes for the primary site and all known secondary sites.

k. Malignant neoplasm without specification of site

Code C80.1, Malignant (primary) neoplasm, unspecified, equates to Cancer, unspecified. This code should only be used when no determination can be made as to the primary site of a malignancy. This code should rarely be used in the inpatient setting.

l. Sequencing of neoplasm codes

1) Encounter for treatment of primary malignancy

If the reason for the encounter is for treatment of a primary malignancy, assign the malignancy as the principal/first-listed diagnosis. The primary site is to be sequenced first, followed by any metastatic sites.

2) Encounter for treatment of secondary malignancy

When an encounter is for a primary malignancy with metastasis and treatment is directed toward the metastatic (secondary) site(s) only, the metastatic site(s) is designated as the principal/first-listed diagnosis. The primary malignancy is coded as an additional code.

3) Malignant neoplasm in a pregnant patient

When a pregnant patient has a malignant neoplasm, a code from subcategory O9A.1-, Malignant neoplasm complicating pregnancy, childbirth, and the puerperium, should be sequenced first, followed by the appropriate code from Chapter 2 to indicate the type of neoplasm.

4) Encounter for complication associated with a neoplasm

When an encounter is for management of a complication associated with a neoplasm, such as dehydration, and the treatment is only for the complication, the complication is coded first, followed by the appropriate code(s) for the neoplasm.

The exception to this guideline is anemia. When the admission/encounter is for management of an anemia associated with the malignancy, and the treatment is only for anemia, the appropriate code for the malignancy is sequenced as the principal or first-listed diagnosis followed by code D63.0, Anemia in neoplastic disease.

5) Complication from surgical procedure for treatment of a neoplasm

When an encounter is for treatment of a complication resulting from a surgical procedure performed for the treatment of the neoplasm, designate the complication as the principal/first-listed diagnosis. See guideline regarding the coding of a current malignancy versus personal history to determine if the code for the neoplasm should also be assigned.

6) Pathologic fracture due to a neoplasm

When an encounter is for a pathological fracture due to a neoplasm, and the focus of treatment is the fracture, a code from subcategory M84.5, Pathological fracture in neoplastic disease, should be sequenced first, followed by the code for the neoplasm. If the focus of treatment is the neoplasm with an associated pathological fracture, the neoplasm code should be sequenced first, followed by a code from M84.5 for the pathological fracture.

m. Current malignancy versus personal history of malignancy

When a primary malignancy has been excised but further treatment, such as an additional surgery for the malignancy, radiation therapy or chemotherapy is directed to that site, the primary malignancy code should be used until treatment is completed.

When a primary malignancy has been previously excised or eradicated from its site, there is no further treatment (of the malignancy) directed to that site, and there is no evidence of any existing primary malignancy, a code from category Z85, Personal history of malignant neoplasm, should be used to indicate the former site of the malignancy. See Section I.C.21. Factors influencing health status and contact with health services, History (of)

n. Leukemia, Multiple Myeloma, and Malignant Plasma Cell Neoplasms in remission versus personal history

The categories for leukemia, and category C90, Multiple myeloma and malignant plasma cell neoplasms, have codes indicating whether or not the leukemia has achieved remission. There are also codes Z85.6, Personal history of leukemia, and Z85.79, Personal history of other malignant neoplasms of lymphoid, hematopoietic and related tissues. If the documentation is unclear as to whether the leukemia has achieved remission, the provider should be queried. See Section I.C.21. Factors influencing health status and contact with health services, History (of)

o. Aftercare following surgery for neoplasm

See Section I.C.21. Factors influencing health status and contact with health services, Aftercare

p. Follow-up care for completed treatment of a malignancy

See Section I.C.21. Factors influencing health status and contact with health services, Follow-up

q. Prophylactic organ removal for prevention of malignancy

See Section I.C. 21, Factors influencing health status and contact with health services, Prophylactic organ removal

r. Malignant neoplasm associated with transplanted organ

A malignant neoplasm of a transplanted organ should be coded as a transplant complication. Assign first the appropriate code from category T86.-, Complications of transplanted organs and tissue, followed by code C80.2, Malignant neoplasm associated with transplanted organ. Use an additional code for the specific malignancy.

s. Breast Implant Associated Anaplastic Large Cell Lymphoma

Breast implant associated anaplastic large cell lymphoma (BIA-ALCL) is a type of lymphoma that can develop around breast implants. Assign code C84.7A, Anaplastic large cell lymphoma, ALK-negative, breast, for BIA-ALCL. Do not assign a complication code from chapter 19.

t. Secondary malignant neoplasm of lymphoid tissue

When a malignant neoplasm of lymphoid tissue metastasizes beyond the lymph nodes, a code from categories C81-C85 with a final character "9" should be assigned identifying "extranodal and solid organ sites" rather than a code for the secondary neoplasm of the affected solid organ. For example, for metastasis of B-cell lymphoma to the lung, brain and left adrenal gland, assign code C83.39, Diffuse large B-cell lymphoma, extranodal and solid organ sites.