Topography Code (ICD-O)

Field Length:  5

Enter the ICD-O 3rd edition Topography code which describes the anatomical site of the patient's primary tumor. This is a five character field. After the "C", enter the three digit code; the decimal point is already in the correct position.

The International Classification of Diseases for Oncology (ICD-O) 3rd edition, represents an extension of Chapter II of the ICD-10 coding reference. ICD-O permits the coding of all neoplasms by topography, morphology, and cell behavior --  providing greater detail than that permitted with ICD-9 or ICD-10 coding schemes.

The structure of the ICD-O reference book contains three major sections:

Topography -                  A numerical list of anatomic sites adapted from the malignant neoplasms section of Chapter II of ICD-10. The topographic terms have 3-digit code numbers preceded by a "C" which run from C00.0 to C80.9.

Morphology -                  A numerical list of histologic terms that is a revised and expanded version of the morphology section of The Manual of Tumor Nomenclature and Coding. The ICD-O, 3rd edition includes new histologic types that have come into the literature since 1990. It has revised the Leukemia and Lymphoma sections and now includes several hematopoietic diseases that were previously considered borderline.

Alphabetic Index -           A list of anatomic sites, histologic terms and selected tumor-like lesions and conditions.

Refer to the introductory pages of the International Classification of Diseases for Oncology, 3rd edition, for a more detailed discussion of the differences between ICD-O and ICD-10, as well as for rules governing the appropriate assignment of ICD-O codes. See also APPENDIX J for errata and clarifications to ICD-O-3rd edition.

Coding Instructions for Solid Tumors

Site-Specific Topography Terms

See the Coding Guidelines for Topography and Morphology in the introduction of the ICD-O-3 for additional details.

1. Unless otherwise instructed, use all available information to code the site.

2. Code the site in which the primary tumor originated, even if it extends onto/into an adjacent subsite.

Example 1: Final diagnosis is adenocarcinoma of the upper lobe of the right lung. Code the topography to lung, upper lobe (C341).

Example 2: The patient has a 4 cm tumor in the right breast. The tumor originated in the upper inner quadrant and extends into the lower inner quadrant. Code the primary site to upper inner quadrant of breast (C502).

Example 3: Patient has a right branchial cleft cyst; the pathology report identifies an adenocarcinoma arising in an ectopic focus of thyroid tissue within the branchial cleft cyst. Thyroidectomy pathology is negative. Code the primary site to branchial cleft (C104).

Example 4: The patient had a total hysterectomy with a bilateral salpingo-oophorectomy ten years ago for non-cancer reasons. She now has widespread cystadenocarcinoma in the peritoneum. Code the primary site to peritoneum, NOS (C482). (The chart may or may not state that the patient has extra-ovarian carcinoma.)

Example 5: Pathology report shows adenocarcinoma arising in a patch of endometriosis on the sigmoid colon. Code the primary site to sigmoid colon (C187), the site in which the cancer originated.

3. Code the last digit of the primary site code to ‘8’ when a single tumor overlaps an adjacent subsite(s) of an organ and the point of origin cannot be determined.

Example: The patient has a 5cm tumor that involves the dorsal surface and anterior 2/3 of tongue. Code the primary site to C028 (overlapping lesion of tongue).

4. Code the site of the invasive tumor when there is an invasive tumor and in situ tumor in different subsites of the same anatomic site.

Example 1: Patient has an invasive breast tumor in the upper-outer quadrant of the left breast and in situ tumor in multiple quadrants of the left breast. Code the primary site to C504 (upper outer quadrant of breast).

Example 2: Patient has in situ Paget disease of the right nipple and invasive duct carcinoma of the lower inner quadrant of the right breast. Code the primary site to C503 (lower inner quadrant).

5. Code the last digit of the primary site code to ‘9’ for single primaries, when multiple tumors arise in different subsites of the same anatomic site and the point of origin cannot be determined.

Example 1: During a TURB, the physician describes multiple papillary tumors in the bladder neck (C675) and the lateral wall of the bladder (C672). Code the primary site as bladder, NOS (C679).

Example 2: Patient has an infiltrating duct tumor in the upper outer quadrant (C504) of the right breast and another infiltrating duct carcinoma in the lower inner (C503) quadrant of the right breast. Code the primary site as breast, NOS (C509).

6. Some histology/behavior terms in ICD-O-3 have a related site code in parentheses; for example: Hepatoma (C220).

a. Code the site as documented in the medical record and ignore the suggested ICD-O-3 code when a primary site is specified in the medical record.

Example: The pathology report says “infiltrating duct carcinoma of the head of the pancreas.” The listing in ICD-O-3 is infiltrating duct carcinoma 8500/3 (C50_). Code the primary site to head of pancreas (C250), NOT to breast (C50_) as suggested by the ICD-O-3.

b. Use the site code suggested by ICD-O-3 when the primary site is the same as the site code suggested or the primary site is unknown

Example 1: The biopsy is positive for hepatoma, and no information is available about the primary site. Code the primary site to liver (C220) as suggested by ICD-O-3.

Example 2: An excision of the right axillary nodes reveals metastatic infiltrating duct carcinoma. The right breast is negative. The ICD-O-3 shows infiltrating duct carcinoma (8500) with a suggested site of breast (C50_). Code the primary site as breast, NOS (C509).

7. Code the primary site, not the metastatic site. If a tumor is metastatic and the primary site is unknown, code the primary site as unknown (C809).

8. See the site-specific Coding Guidelines in Appendix C for primary site coding guidelines for the following sites:

Bladder                    Kaposi sarcoma                      

Breast                      Lung

Colon                       Rectosigmoid, rectum

Esophagus

9. See below for primary site coding guidelines for Sarcoma.

10. Code C422 (Spleen) as the primary site for angiosarcoma of spleen with mets to bone marrow.

11. Gastrointestinal Stromal Tumors (GIST): Code the primary site to the location where the malignant GIST originated.

12. In the absence of any additional information, assign the codes listed for these primary sites

13. When the medical record does not contain enough information to assign a primary site:

a. Consult a physician advisor to assign the site code.

b. Use the NOS category for the organ system or the Ill-Defined Sites (C760-C768) if the physician advisor cannot identify a primary site.

c. Code Unknown Primary Site (C809) if there is not enough information to assign an NOS or Ill-Defined Site category.

Sarcoma

The majority of sarcomas arise in mesenchymal or connective tissues that are located in the musculoskeletal system, which includes the fat, muscles, blood vessels, deep skin tissues, nerves, bones, and cartilage. The default code for sarcomas of unknown primary site is C499 rather than C809.

Sarcomas may also arise in the walls of hollow organs and in the viscera covering an organ. Code the primary site to the organ of origin.

Example: The pathology identifies a carcinosarcoma of the uterine corpus. Code the primary site to corpus uteri (C549).

Coding Instructions for Hematopoietic and Lymphoid Neoplasms (9590/3-9992/3)

See the Hematopoietic Manual and Database for instructions on coding the primary site for hematopoietic and lymphoid neoplasms.