2024 ICD-10-CM Diagnosis Code C09.1

Malignant neoplasm of tonsillar pillar (anterior) (posterior)

ICD-10-CM Code:
ICD-10 Code for:
Malig neoplasm of tonsillar pillar (anterior) (posterior)
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Code Navigator:

Code Classification

  • Neoplasms
    • Malignant neoplasms of lip, oral cavity and pharynx
      • Malignant neoplasm of tonsil

C09.1 is a billable diagnosis code used to specify a medical diagnosis of malignant neoplasm of tonsillar pillar (anterior) (posterior). The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2023 through September 30, 2024.

The following anatomical sites found in the Table of Neoplasms reference this diagnosis code given the correct histological behavior: Neoplasm, neoplastic fauces, faucial NEC pillars ; Neoplasm, neoplastic glossopalatine fold ; Neoplasm, neoplastic oropharynx pillars or fauces ; Neoplasm, neoplastic palatoglossal arch ; Neoplasm, neoplastic palatopharyngeal arch ; Neoplasm, neoplastic pillars of fauces ; Neoplasm, neoplastic tonsil pillar (anterior) (posterior) ; etc

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Malignant melanoma of oral cavity
  • Malignant melanoma of palatine arch
  • Malignant tumor of anterior pillar of fauces
  • Malignant tumor of tonsillar pillar
  • Primary malignant neoplasm of tonsillar pillar
  • Primary squamous cell carcinoma of tonsillar pillar
  • Tumor of anterior pillar of fauces

Clinical Classification

Convert C09.1 to ICD-9-CM

  • ICD-9-CM Code: 146.2 - Mal neo tonsil pillars

Table of Neoplasms

This code is referenced in the table of neoplasms by anatomical site. For each site there are six possible code numbers according to whether the neoplasm in question is malignant, benign, in situ, of uncertain behavior, or of unspecified nature. The description of the neoplasm will often indicate which of the six columns is appropriate.

Where such descriptors are not present, the remainder of the Index should be consulted where guidance is given to the appropriate column for each morphological (histological) variety listed. However, the guidance in the Index can be overridden if one of the descriptors mentioned above is present.

Neoplasm, neoplastic Malignant
CaInSitu Benign Uncertain
»Neoplasm, neoplastic
  »fauces, faucial NEC
»Neoplasm, neoplastic
  »glossopalatine fold
»Neoplasm, neoplastic
    »pillars or fauces
»Neoplasm, neoplastic
  »palatoglossal arch
»Neoplasm, neoplastic
  »palatopharyngeal arch
»Neoplasm, neoplastic
  »pillars of fauces
»Neoplasm, neoplastic
    »pillar (anterior) (posterior)

Patient Education

Throat Cancer

Throat cancer is a type of head and neck cancer. Throat cancer has different names, depending on which part of the throat is affected. The different parts of your throat are called the oropharynx, the hypopharynx, the nasopharynx, and the larynx, or voice box.

The main risk factors for throat cancer are using tobacco heavy drinking. Certain types of throat cancer also have other risk factors. For example, having HPV is a risk factor for oropharyngeal cancer.

Symptoms of throat cancer may include:

  • A sore throat that does not go away
  • A lump in the neck
  • Pain or ringing in the ears
  • Trouble swallowing
  • Ear pain

To diagnose throat cancers, doctors may do a physical exam and history, imaging tests, and a biopsy. You may also need other tests, depending on the type of cancer. Treatments include surgery, radiation therapy, and chemotherapy. Treatment for some types of throat cancer may also include targeted therapy. Targeted therapy uses drugs or other substances that attack specific cancer cells with less harm to normal cells.

NIH: National Cancer Institute

[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.


[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.