2024 ICD-10-CM Diagnosis Code C21.0

Approximate Synonyms

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

• Adenocarcinoma of anus
• Anorectal adenocarcinoma
• Anorectal adenocarcinoma
• Carcinoma of anus
• Lymphoma of anus
• Malignant mesenchymal neoplasm of anus
• Malignant neoplasm of rectum, rectosigmoid junction and anus
• Malignant tumor of anus
• Malignant tumor of rectosigmoid junction
• Primary adenocarcinoma of anus
• Primary malignant mesenchymal neoplasm of anus
• Primary malignant neoplasm of anus
• Primary sarcoma of perineum
• Primary squamous cell carcinoma of anus

C21.0 is grouped with Diagnostic Related Groups - MS-DRG Mapping

Diagnostic Related Groups (DRGs) are a classification system used to group together diagnosis codes for the purpose of reimbursement and healthcare management. DRGs are used to standardize the way hospitals and other providers are paid for inpatient services. In this system patients are grouped together based on their principal diagnosis in areas referred to as Major Diagnostic Categories (MDC). Once a patient is assigned a particular diagnostic category, providers receive a predetermined payment rate for the services rendered. This reimbursement rate is often fixed and is meant to cover the cost of care for that patient. Reimbursement is also affected by the relative weight of a diagnostic related group based on the severity of a patient's illness and the associated cost of care during hospitalization.

Diagnostic related groups encourage healthcare providers to focus on quality and efficiency in patient care while managing costs effectively. The diagnosis code is present in the following groups for version MS-DRG V41.0 applicable from 10/01/2023 through 09/30/2024.

MS-DRG	MS-DRG Title	MCD	Relative Weight
374	DIGESTIVE MALIGNANCY WITH MCC	06	2.099
375	DIGESTIVE MALIGNANCY WITH CC	06	1.1983
376	DIGESTIVE MALIGNANCY WITHOUT CC/MCC	06	0.8914

The relative weight of a diagnostic related group determines the reimbursement rate based on the severity of a patient's illness and the associated cost of care during hospitalization.

Convert C21.0 to ICD-9-CM

• ICD-9-CM Code: 154.3 - Malignant neo anus NOS

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.

Filter table of neoplasms:

Neoplasm, neoplastic	Malignant Primary	Malignant Secondary	CaInSitu	Benign	Uncertain Behavior	Unspecified Behavior
»Neoplasm, neoplastic   »anus, anal	C21.0	C78.5	D01.3	D12.9	D37.8	D49.0

Patient Education

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

[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.