ICD-10 Diagnosis Code C21.0

Malignant neoplasm of anus, unspecified

Diagnosis Code C21.0

ICD-10: C21.0
Short Description: Malignant neoplasm of anus, unspecified
Long Description: Malignant neoplasm of anus, unspecified
This is the 2017 version of the ICD-10-CM diagnosis code C21.0

Valid for Submission
The code C21.0 is valid for submission for HIPAA-covered transactions.

Code Classification
  • Neoplasms (C00–D48)
    • Malignant neoplasms of digestive organs (C15-C26)
      • Malignant neoplasm of anus and anal canal (C21)

Information for Medical Professionals

Diagnostic Related Groups
The diagnosis code C21.0 is grouped in the following Diagnostic Related Group(s) (MS-DRG V34.0)


Convert to ICD-9 Additional informationCallout TooltipGeneral Equivalence Map
The ICD-10 and ICD-9 GEMs are used to facilitate linking between the diagnosis codes in ICD-9-CM and the new ICD-10-CM code set. The GEMs are the raw material from which providers, health information vendors and payers can derive specific applied mappings to meet their needs.
  • 154.3 - Malignant neo anus NOS

  • Adenocarcinoma of anorectum
  • Adenocarcinoma of anus
  • Malignant epithelial neoplasm of anus
  • Malignant neoplasm of rectum, rectosigmoid junction and anus
  • Malignant tumor of anus
  • Malignant tumor of anus and anal canal
  • Primary malignant neoplasm of anus

Information for Patients

Anal Cancer

The anus is where stool leaves your body when you go to the bathroom. It is made up of your outer layers of skin and the end of your large intestine. Anal cancer is a disease in which cancer cells form in the tissues of the anus.

Anal cancer is rare. It is more common in smokers and people over 50. You are also at higher risk if you have HPV, have anal sex, or have many sexual partners.

Symptoms include bleeding, pain, or lumps in the anal area. Anal itching and discharge can also be signs of anal cancer.

Doctors use tests that examine the anus to diagnose anal cancer. They include a physical exam, endoscopy, ultrasound, and biopsy.

Treatments include radiation therapy, chemotherapy, and surgery.

NIH: National Cancer Institute

  • After chemotherapy - discharge
  • Anal cancer
  • Anoscopy
  • Pelvic (between the hips) radiation - discharge
  • Understanding Chemotherapy - NIH - Easy-to-Read (National Cancer Institute)
  • What to Know about External Beam Radiation Therapy - NIH - Easy-to-Read (National Cancer Institute)

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