Glioblastoma ICD 10 Code

Refresher: What Are ICD 10 Codes?

ICD-10 stands for the International Classification of Diseases, 10th revision. It is a coding system used in healthcare to classify diagnoses, procedures, and symptoms systematically. CM indicates “Clinical Modification,” which is used in the U.S. for disease diagnoses (ICD-10-CM). ICD-10-PCS codes are used for coding procedures in inpatient settings. Both of these coding systems are used for medical claims and statistics purposes.

The history of the International Classification of Diseases (ICD) shows that the first edition of the coding system came out in the 1850s. Known as the International List of Causes of Death, this initial version was adopted by the International Statistical Institute in 1893 for early use. WHO took control of the ICD coding system in 1948 to track, classify, and eliminate diseases from several populations with many affected patients. The organization introduced the Sixth Revision (ICD 6) to highlight the causes of morbidity in the previous coding system version. WHO analyzed the gaps and formulated new versions (revisions) to address the problems of the previous versions. The organization developed ICD 7 and ICD 8 in 1957 and 1968, respectively, to meet the challenges of disease classification more efficiently. The coding system's Ninth Revision (ICD 9) emerged in 1979. The U.S. adopted the Ninth Revision and developed an exclusive version of ICD 9-CM (clinical modification). [¹]

ICD 9-CM set the ground rules for further developments to capture enhanced morbidity data (for calculating disease rates in populations). The new edition also incorporated surgical procedures and other parts necessary for categorizing the needs of hospitals. Although the Ninth Revision encompassed several crucial variables, it had a limited capacity to assign codes. After years of research and development, CMS and the NCHS introduced a new ICD 10-CM (Tenth Revision, clinical modification) to establish a comprehensive classification system with no flaws (as observed in the previous versions).

In general, ICD-10 codes are different for primary cancers (“malignant neoplasms”) and for metastatic lung cancer (“secondary malignant neoplasms”). [²]

What Is the ICD 10 Code for Glioblastoma?

For primary Glioblastoma, the general ICD-10 code is C71.9 (malignant neoplasm of the brain, unspecified), whereas for secondary or metastatic tumors, the ICD-10 code is C79.31 (secondary malignant neoplasm of the brain).

Primary Glioblastoma ICD 10 Code: C71.9

Primary Glioblastoma ICD Code C71.9 Lookup

The ICD 10 glioblastoma code for primary cancer forms, which is classified under C71.9, “malignant neoplasm of brain, unspecified.” [³] does not have separate coding for subsites.

Types of Glioblastoma Coded Under C71.9

The ICD 10 code C71.9 does not specify the subtype of glioblastoma. A C71.9 code can also apply to primary glioblastoma (cancer) of various cell types. Since this tumor develops in the brain, it does not have specific types based on cell formation. Only primary (de novo) glioblastoma falls under C71.9.

If a patient is diagnosed with glioblastoma, they are more likely to develop primary glioblastoma that allows rapid growth of cancerous cells in the brain.

Secondary and Metastatic Glioblastoma ICD 10 Code: C79.31

Secondary or Metastatic Glioblastoma ICD 10 Code C79.31 Lookup

Secondary or metastatic cancers spread from other parts of the body after affecting the primary site. The cancers metastasized from other locations may form the same tumor as in the primary site. The ICD 10 glioblastoma code for secondary glioblastoma (cancer), or glioblastoma metastasized from other locations, is C79.31, “secondary malignant neoplasm of brain.” [⁴]

Conclusion

The ICD 10 code for glioblastoma depends on where the tumor develops in the brain and how aggressively it grows. Patients are most likely to get primary glioblastoma, which is an aggressive brain tumor that significantly reduces life expectancy. Glioblastoma does not contain subsites and is only classified by ICD 10 code C71.9. The secondary glioblastoma ICD 10 code is C79.31 (secondary malignant neoplasm of the brain). When studying the ICD 10 codes for brain tumors (glioblastoma and others), you may remember that the coding system does not specify the accurate location of tumor development and its type. Since glioblastoma is a specified form of brain tumor, the subsite classification becomes invalid (you may be unable to find it in databases). Evaluation of the ICD 10 code for glioblastoma depends on multiple factors, including the origin and pathophysiology of glioblastoma and the patient’s pre-established health condition.