2024 ICD-10-CM Diagnosis Code C56.9

Malignant neoplasm of unspecified ovary

ICD-10-CM Code:
ICD-10 Code for:
Malignant neoplasm of unspecified ovary
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Code Navigator:

Code Classification

  • Neoplasms
    • Malignant neoplasms of female genital organs
      • Malignant neoplasm of ovary

C56.9 is a billable diagnosis code used to specify a medical diagnosis of malignant neoplasm of unspecified ovary. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2023 through September 30, 2024.

This code is applicable to female patients only. It is clinically and virtually impossible to use this code on a non-female patient.

Unspecified diagnosis codes like C56.9 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

Approximate Synonyms

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

  • Anemia in neoplastic disease
  • Anemia in ovarian carcinoma
  • Carcinoma of ovary, stage 1
  • Carcinoma of ovary, stage 2
  • Carcinoma of ovary, stage 3
  • Carcinoma of ovary, stage 4
  • Carcinosarcoma of ovary
  • Carcinosarcoma of uterine adnexa
  • Choriocarcinoma
  • Choriocarcinoma
  • Choriocarcinoma of ovary
  • Clear cell neoplasm of ovary
  • Clear cell adenocarcinoma of ovary
  • Cystadenocarcinoma of ovary
  • Embryonal carcinoma
  • Embryonal carcinoma
  • Embryonal carcinoma of ovary
  • Endodermal sinus tumor of ovary
  • Endometrioid carcinoma ovary
  • Epithelial ovarian tumor, FIGO stage II
  • Epithelial ovarian tumor, FIGO stage IIC
  • Familial cancer of breast
  • Familial ovarian cancer
  • Familial ovarian cancer
  • FIGO ovarian tumor stage finding
  • FIGO ovarian tumor stage finding
  • FIGO stage finding for epithelial tumor of ovary
  • FIGO stage finding for epithelial tumor of ovary
  • Germ cell tumor of ovary
  • Hereditary breast and ovarian cancer syndrome
  • Hereditary site-specific ovarian cancer syndrome
  • Invasive ovarian tumor omental implants absent
  • Invasive ovarian tumor omental implants present
  • Malignant dysgerminoma of ovary
  • Malignant epithelial tumor of ovary
  • Malignant germ cell tumor of ovary
  • Malignant immature teratoma of ovary
  • Malignant non-dysgerminomatous germ cell tumor of ovary
  • Malignant sex cord tumor of ovary
  • Malignant teratoma
  • Malignant tumor involving an organ by direct extension from ovary
  • Malignant tumor involving bladder by direct extension from ovary
  • Malignant tumor involving left broad ligament by direct extension from ovary
  • Malignant tumor involving left fallopian tube by direct extension from ovary
  • Malignant tumor involving rectum by direct extension from ovary
  • Malignant tumor involving right broad ligament by direct extension from ovary
  • Malignant tumor involving right fallopian tube by direct extension from ovary
  • Malignant tumor involving uterine cervix by direct extension from ovary
  • Malignant tumor involving uterine corpus by direct extension from ovary
  • Malignant tumor involving vagina by direct extension from ovary
  • Malignant tumor involving vulva by direct extension from ovary
  • Malignant tumor of ovary
  • Mucinous cystadenocarcinoma of ovary
  • Neoplasm of uncertain behavior of ovary
  • Non-invasive ovarian tumor omental implants absent
  • Non-invasive ovarian tumor omental implants absent
  • Non-invasive ovarian tumor omental implants present
  • Non-invasive ovarian tumor omental implants present
  • Polyembryoma
  • Primary cystadenocarcinoma of ovary
  • Primary high grade serous adenocarcinoma of ovary
  • Primary low grade serous adenocarcinoma of ovary
  • Primary malignant neoplasm of ovary
  • Primary mucinous adenocarcinoma of ovary
  • Primary mucinous carcinoma of uterine adnexa
  • Primary mucinous cystadenocarcinoma of ovary
  • Primary non-gestational choriocarcinoma of ovary
  • Primary serous carcinoma of uterine adnexa
  • Primary serous papillary cystadenocarcinoma ovary
  • Primary undifferentiated carcinoma of ovary
  • Recurrent malignant neoplastic disease
  • Recurrent ovarian cancer
  • Sarcoma of ovary
  • Serous cystadenoma borderline malignancy of ovary
  • Serous papillary cystadenocarcinoma ovary
  • Small cell carcinoma of ovary
  • Teratoma of ovary
  • Theca steroid producing cell malignant neoplasm of ovary
  • Undifferentiated carcinoma of ovary
  • Yolk sac tumor
  • Yolk sac tumor

Clinical Classification

Clinical Information

  • Choriocarcinoma

    a malignant metastatic form of trophoblastic tumors. unlike the hydatidiform mole, choriocarcinoma contains no chorionic villi but rather sheets of undifferentiated cytotrophoblasts and syncytiotrophoblasts (trophoblasts). it is characterized by the large amounts of chorionic gonadotropin produced. tissue origins can be determined by dna analyses: placental (fetal) origin or non-placental origin (choriocarcinoma, non-gestational).
  • Choriocarcinoma, Non-gestational

    a highly malignant choriocarcinoma derived from the non-placental origin such as the totipotent cells in the testis, the ovary, and the pineal gland. it produces high levels of chorionic gonadotropin and can metastasize widely through the bloodstream to the lungs, brain, liver, bone, and other viscera by the time of diagnosis.
  • Hereditary Breast and Ovarian Cancer Syndrome

    autosomal dominant hereditary cancer syndrome in which a mutation most often in either brca1 or brca2 is associated with a significantly increased risk for breast and ovarian cancers.
  • Neoplastic Syndromes, Hereditary

    the condition of a pattern of malignancies within a family, but not every individual's necessarily having the same neoplasm. characteristically the tumor tends to occur at an earlier than average age, individuals may have more than one primary tumor, the tumors may be multicentric, usually more than 25 percent of the individuals in direct lineal descent from the proband are affected, and the cancer predisposition in these families behaves as an autosomal dominant trait with about 60 percent penetrance.

Index to Diseases and Injuries References

The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).

  • - Cancer - See Also: Neoplasm, by site, malignant;
    • - ovarian - See Also: Neoplasm ovary, malignant; - C56.9

Code Edits

The Medicare Code Editor (MCE) detects and reports errors in the coding of claims data. The following ICD-10-CM Code Edits are applicable to this code:

  • Diagnoses for females only - The Medicare Code Editor detects inconsistencies between a patient’s sex and any diagnosis on the patient’s record, these edits apply to FEMALES only .

Convert C56.9 to ICD-9-CM

  • ICD-9-CM Code: 183.0 - Malign neopl ovary
    Approximate Flag - The approximate mapping means there is not an exact match between the ICD-10 and ICD-9 codes and the mapped code is not a precise representation of the original code.

Patient Education

Ovarian Cancer

What is ovarian cancer?

Cancer is a disease in which abnormal cells in the body grow out of control and form a tumor. Ovarian cancer is a cancerous tumor that forms in the tissues of an ovary. The ovaries are a pair of female reproductive glands that make eggs and female hormones.

What are the types of ovarian cancer?

There are a few different types of ovarian cancer. The most common type is epithelial cancer. It begins in the cells that cover the ovary.

There are also two related types of epithelial cancer that can spread to the ovaries:

  • Fallopian tube cancer forms in the tissue lining a fallopian tube. The fallopian tubes are a pair of long, slender tubes on each side of the uterus. The uterus is the female reproductive organ where a baby grows during pregnancy.
  • Primary peritoneal cancer forms in the tissue lining the peritoneum. Your peritoneum is a tissue lining that covers the organs in the abdomen (belly).

These two cancers are similar to ovarian cancer, and they have the same treatments. So some medical experts also consider those two types as ovarian cancer.

Some other rarer types of ovarian cancer are malignant germ cell tumors and stromal tumors.

What causes ovarian cancer?

Ovarian cancer happens when there are changes (mutations) in the genetic material (DNA). Often, the exact cause of these genetic changes is unknown.

Most ovarian cancers are caused by genetic changes that happen during your lifetime. But sometimes these genetic changes are inherited, meaning that you are born with them. Ovarian cancer that is caused by inherited genetic changes is called hereditary ovarian cancer.

There are also certain genetic changes that can raise your risk of ovarian cancer, including changes called BRCA1 and BRCA2. These two changes also raise your risk of breast and other cancers.

Besides genetics, your lifestyle and the environment can affect your risk of ovarian cancer.

Who is more likely to develop ovarian cancer?

Certain people are more likely to develop ovarian cancer. They include those who:

  • Have a family history of ovarian cancer in a mother, daughter, or sister
  • Have inherited changes in the BRCA1 or BRCA2 genes.
  • Have certain other genetic conditions, such as Lynch syndrome
  • Have endometriosis
  • Took hormone replacement therapy
  • Are overweight or have obesity
  • Are tall
  • Are older, especially those who have gone through menopause

What are the symptoms of ovarian cancer?

Ovarian cancer may not cause early signs or symptoms. By the time you do have signs or symptoms, the cancer is often advanced.

The signs and symptoms may include:

  • Pain, swelling, or a feeling of pressure in the abdomen or pelvis
  • Sudden or frequent urge to urinate (pee)
  • Trouble eating or feeling full
  • A lump in the pelvic area
  • Gastrointestinal problems, such as gas, bloating, or constipation

How is ovarian cancer diagnosed?

To find out if you have ovarian cancer, your health care provider:

  • Will ask about your medical history, including your symptoms
  • Will ask about your family health history, including relatives who have had ovarian cancer
  • Will do a physical exam, including a pelvic exam
  • Will likely do imaging tests
  • May do blood tests such as a CA-125 blood test

Often the only way to know for sure that you have ovarian cancer is by having a biopsy of the tissue. A biopsy is done during surgery to remove the tumor.

What are the treatments for ovarian cancer?

Treatments for ovarian cancer may include:

  • Surgery to remove as much of the cancer as possible
  • Chemotherapy
  • Targeted therapy, which uses drugs or other substances that attack specific cancer cells with less harm to normal cells

Your provider may suggest that you have genetic testing to look for the gene changes that raise the risk for ovarian cancer. Knowing whether or not you have the gene change may help your provider decide on your treatment plan.

NIH: National Cancer Institute

[Learn More in MedlinePlus]

Ovarian cancer

Ovarian cancer is a disease that affects women. In this form of cancer, certain cells in the ovary become abnormal and multiply uncontrollably to form a tumor. The ovaries are the female reproductive organs in which egg cells are produced. In about 90 percent of cases, ovarian cancer occurs after age 40, and most cases occur after age 60.

The most common form of ovarian cancer begins in epithelial cells, which are the cells that line the surfaces and cavities of the body. These cancers can arise in the epithelial cells on the surface of the ovary. However, researchers suggest that many or even most ovarian cancers begin in epithelial cells on the fringes (fimbriae) at the end of one of the fallopian tubes, and the cancerous cells migrate to the ovary.

Cancer can also begin in epithelial cells that form the lining of the abdomen (the peritoneum). This form of cancer, called primary peritoneal cancer, resembles epithelial ovarian cancer in its origin, symptoms, progression, and treatment. Primary peritoneal cancer often spreads to the ovaries. It can also occur even if the ovaries have been removed. Because cancers that begin in the ovaries, fallopian tubes, and peritoneum are so similar and spread easily from one of these structures to the others, they are often difficult to distinguish. These cancers are so closely related that they are generally considered collectively by experts.

In about 10 percent of cases, ovarian cancer develops not in epithelial cells but in germ cells, which are precursors to egg cells, or in hormone-producing ovarian cells called granulosa cells.

In its early stages, ovarian cancer usually does not cause noticeable symptoms. As the cancer progresses, signs and symptoms can include pain or a feeling of heaviness in the pelvis or lower abdomen, bloating, feeling full quickly when eating, back pain, vaginal bleeding between menstrual periods or after menopause, or changes in urinary or bowel habits. However, these changes can occur as part of many different conditions. Having one or more of these symptoms does not mean that a woman has ovarian cancer.

In some cases, cancerous tumors can invade surrounding tissue and spread to other parts of the body. If ovarian cancer spreads, cancerous tumors most often appear in the abdominal cavity or on the surfaces of nearby organs such as the bladder or colon. Tumors that begin at one site and then spread to other areas of the body are called metastatic cancers.

Some ovarian cancers cluster in families. These cancers are described as hereditary and are associated with inherited gene mutations. Hereditary ovarian cancers tend to develop earlier in life than non-inherited (sporadic) cases.

Because it is often diagnosed at a late stage, ovarian cancer can be difficult to treat; it leads to the deaths of about 14,000 women annually in the United States, more than any other gynecological cancer. However, when it is diagnosed and treated early, the 5-year survival rate is high.

[Learn More in MedlinePlus]

Ovarian Epithelial, Fallopian Tube, and Primary Peritoneal Cancer Treatment (PDQ®)

Learn about ovarian epithelial, fallopian tube, and primary peritoneal cancer risk factors, symptoms, tests to diagnose, factors affecting prognosis, staging, and treatment.
[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.