What are the other Names for this Condition? (Also known as/Synonyms)

• Carcinoid Tumor of Uterine Corpus
• Carcinoid Tumor of Uterus
• Primary Uterine Carcinoid Tumor

What is Primary Carcinoid Tumor of Uterus? (Definition/Background Information)

• Primary Carcinoid Tumor of Uterus is a very rare and usually benign neuroendocrine tumor that originates in the lining of the uterus (endometrium). When examined by a pathologist under the microscope, the tumor consists of neuroendocrine cells that are usually uniform in size, but shows mitotic activity (low tumor proliferation)
• Even though there are no specific risk factors for Primary Carcinoid Tumor of Uterus, there are generally established risk factors for endometrial cancers including obesity, poorly-controlled diabetes, positive family history of endometrial cancer, and polycystic ovarian syndrome. The exact cause of tumor development is unknown, but it may be due to certain genetic abnormalities
• Most these tumors are detected and diagnosed in women aged 50 years and older (postmenopausal women). The majority of Primary Carcinoid Tumor of Uterus cases may be detected and diagnosed at an early stage, due to abnormal vaginal bleeding. Additional signs and symptoms may include pelvic pain, pain during sex, and urination difficulties
• Primary Carcinoid Tumor of Uterus is generally a benign tumor, and hence, its prognosis is excellent. Nevertheless, since the tumor is very rarely associated with an increased risk for endometrial cancer, periodic checkups and screening mammograms are advised

Note: Primary atypical carcinoid tumor of uterus: These tumors may be malignant and are treated with a simple excision. However, such tumors are extremely rare.

Who gets Primary Carcinoid Tumor of Uterus? (Age and Sex Distribution)

• Neuroendocrine carcinomas of the uterus account for less than 1% of all endometrial cancers in women
• Primary Carcinoid Tumors of Uterus cases are generally observed in women aged 50 years and older. Women under the age of 40 years are rarely diagnosed with such uterine tumors
• All racial and ethnic groups may be affected; the condition is observed worldwide in women

What are the Risk Factors for Primary Carcinoid Tumor of Uterus? (Predisposing Factors)

Currently, there are no specific risk factors for Primary Carcinoid Tumors of Uterus, since they are very rare. However, the following factors are noted to increase the risk for the development of endometrial cancer:

• Advancing age: The risk increases as one ages, and most cases occur between the ages 55 and 70 years
• Obesity: Obese women have an elevated risk for developing the condition
• Menstrual cycle: Women who got their period before the age of 12 years, and those who reached menopause after age 55 years have an elevated risk. The longer the duration between menarche and menopause, the greater is the risk. This is due to hormonal influences during the reproductive period on the endometrial tissue
• Polycystic ovarian syndrome (PCOS): Polycystic ovarian syndrome is a condition in which women’s hormones are out of balance. It is one of the most common endocrine disorders in women
• Family history: Neuroendocrine tumors of uterus may be prevalent in families. Individuals with an associated history of colon cancer may be at a significantly higher risk. Individuals with one or more immediate family members or relatives with a history of colon cancer or non-polyposis colorectal cancer (HNPCC), may have an increased risk
• Endometrial hyperplasia: It is an abnormal overgrowth of the endometrium that is usually caused by hormonal effects. Hyperplasia is not a type of cancer; however, women with atypical endometrial hyperplasia have a much greater risk for getting endometrial cancer in their lifetime
• Poor dietary choices: Individuals, taking a diet that consists of foods high in animal fat, may have an increased risk for developing this cancer type
• Tamoxifen therapy: Women, on the hormone therapy drug tamoxifen, to treat or prevent breast cancer may be at an increased risk. Nevertheless, women are advised to discuss the risk and benefits of the therapy with their physician
• Estrogen therapy for a long duration
• Diabetes: Researchers believe this may be linked to the high obesity rates found in individuals with type II diabetes
• Radiation therapy: Women who had had radiation therapy to the pelvis for other cancers are at an increased risk
• High blood pressure
• History of breast cancer and ovarian cancer
• Any other condition causing hormonal imbalance in the body, such as use of birth-control pills or pregnancy
• Use of intrauterine contraceptive devices (IUDs)

Note: Nulliparous women, or women who have never been pregnant, are not known to have an increased risk for neuroendocrine tumors of uterus.

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Primary Carcinoid Tumor of Uterus? (Etiology)

The exact cause and mechanism of formation of Primary Carcinoid Tumor of Uterus is unknown. Some researchers believe that the tumor occurs due to genetic mutations within the cells in the endometrium (the lining of the uterus). Many cases are seen to involve abnormalities in chromosomes 4, 8, and 10.

• In general, it is known that cancers and tumors form when normal, healthy cells begin transforming into abnormal cells - these cancer cells grow and divide uncontrollably (and lose their ability to die), resulting in the formation of a mass or a tumor
• The transformation of normally healthy cells into cancerous cells may be the result of genetic mutations. Mutations allow the cancer cells to grow and multiply uncontrollably to form new cancer cells
• These tumors can invade nearby tissues and adjoining body organs, and even metastasize and spread to other regions of the body

Currently, medical research is being conducted to determine the exact cause of Primary Carcinoid Tumor of Uterus.

What are the Signs and Symptoms of Primary Carcinoid Tumor of Uterus?

Due to the presence of significant signs and symptoms in the initial periods, Primary Carcinoid Tumor of Uterus is generally diagnosed at an early stage. However, if there are associated underlying conditions presenting overlapping signs and symptoms, there could be a delay in diagnosis.

The signs and symptoms that are typically observed early in Primary Carcinoid Tumor of Uterus may include:

• Postmenopausal abnormal vaginal bleeding, spotting, or discharge
• Painful and difficulty during urination
• Pain during sexual intercourse
• Abdominal pain (the pain is usually a pelvic pain)

In more advanced cases, the following signs and symptoms may be observed:

• Abdominal swelling due to the mass or due to fluid accumulation in the belly (called ascites)
• Persistent feeling of abdominal bloating with nausea or vomiting
• Changes in bowel movements, such as constipation
• Feeling full soon, after eating less
• Loss of appetite with weight loss
• Fatigue, feeling tired easily
• Frequent urination (polyuria)

How is Primary Carcinoid Tumor of Uterus Diagnosed?

There is a variety of tests healthcare providers may use to detect, locate, and diagnose Primary Carcinoid Tumor of Uterus and if it has potentially spread to other regions. A surgical procedure called a biopsy (usually performed by an obstetrician-gynecologist) is the main test a healthcare provider relies on to make a definitive diagnosis of Carcinoid Tumor of Uterus.

The diagnostic tools may include:

• A thorough physical examination and a complete medical history evaluation is very vital to the diagnosis
• Pelvic examination: During a pelvic examination, a physician exams the uterus, vagina, ovaries, fallopian tubes, bladder, and rectum to check for any abnormal changes in these organs
• Complete blood count (CBC) with differential of white blood cells
• Liver function test (LFT)
• Blood tests called serum tumor markers that include:
  • CA-125 test
  • Human chorionic gonadotropin (hCG)
  • Alpha-fetoprotein (AFP)
  • Lactate dehydrogenase (LDH)
  • Inhibin (hormone)
  • Estrogen and testosterone levels
• Hysteroscopy: During hysteroscopy, a physician inserts a tiny telescope through the cervix into the uterus. This procedure is used to remove small amounts of the endometrium for pathological examination
• Cystoscopy: During cystoscopy, a physician inserts a narrow tube called cystoscope, to look directly into the bladder to see if cancer from endometrium has spread to the bladder. To make an individual more comfortable during this test, a local anesthetic is usually administered
• Proctoscopy: During proctoscopy, a physician inserts a narrow tube called proctoscope, to look directly into the rectum to see if cancer from endometrium has spread to the rectum. To make an individual more comfortable during this test, a general anesthetic is usually administered.
• Dilation and curettage (D&C) of the uterus: If the biopsy was inadequate in procuring enough tissue samples, or a physician is unsure whether cancer exists, a procedure called dilation and curettage may be necessary. A D&C of the uterus procedure involves opening the cervix and surgically removing the inner lining and tissue present in the uterus. To make an individual more comfortable during this procedure, a general anesthetic is usually administered
• X-ray of the abdomen and pelvic region
• Chest X-ray: Chest X-rays are used to detect if the cancer has spread to the lung
• Barium enema X-ray
• Computerized tomography (CT) scan of the abdomen and pelvic region: Also known as CAT scan, this radiological procedure creates detailed three-dimensional images of structures inside the body. CT scans are not tools of preference to detect Primary Carcinoid Tumor of Uterus. Although CT scans may be helpful in detecting recurrences, or if metastasis to other organs has occurred
• MRI scan of abdomen and pelvic region
• Transvaginal ultrasound: Transvaginal ultrasound inserts an ultrasound probe into the vagina designed to take pictures of the insides of the uterus
• Vascular radiological studies of abdomen and pelvic region
• Endometrial biopsy: A biopsy refers to a medical procedure that involves the removal of cells or tissues, which are then examined by a pathologist under a microscope. After putting together the clinical findings, special studies on tissues (if needed), and the microscope findings, the pathologist arrives at a definitive diagnosis. Sometimes, the pathologist may perform special studies that may include immunohistochemical stains, histochemical stains, molecular testing, and very rarely, electron microscopic studies. Examination of the biopsy under a microscope by a pathologist is considered to be the gold standard in arriving at a conclusive diagnosis

Note: Pap smear is not a good screening tool for Primary Carcinoid Tumor of Uterus.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Primary Carcinoid Tumor of Uterus?

The complications of Primary Carcinoid Tumor of Uterus include:

• Emotional distress due to a concern of cancer
• A majority of the carcinoid tumors are benign; though in some cases, they may become malignant
• Perforation in the uterus, which may occur during a diagnostic D&C or endometrial biopsy procedure
• Recurrence of the tumor following incomplete surgical removal

How is Primary Carcinoid Tumor of Uterus Treated?

The following treatment methods for Primary Carcinoid Tumor of Uterus may be considered:

• A simple surgical excision and removal of the entire primary carcinoid tumor is normally sufficient treatment
• If spread of cancer is noted (atypical carcinoid tumors), then apart from surgery, chemotherapy, and radiation therapy may be necessary
• Follow-up care and regular checkup visits may be recommended by the healthcare provider

How can Primary Carcinoid Tumor of Uterus be Prevented?

Currently, there are no known and available methods to prevent Primary Carcinoid Tumor of Uterus. However, various steps may be taken to help decrease the incidence risk:

• Physical activity: Obesity increases the risk of cancer due to additional related risk factors, such as increased estrogen level, polycystic ovary syndrome, reduced physical activity, and a diet high in saturated fats. Therefore, individuals with higher physical activity levels have a decreased risk of developing Primary Carcinoid Tumor of Uterus
• Pregnancy: During pregnancy, the estrogen levels are lowered. Being pregnant may lower a woman’s risk for Primary Carcinoid Tumor of Uterus. Women, who have multiple pregnancies in their lifetime, may have a decreased risk
• Combination of oral contraceptives: Taking a combination of oral contraceptives, such as estrogen and progestin, decrease the risk of Primary Carcinoid Tumor of Uterus. The protective effect of a combination of oral contraceptives increases, the longer they are taken; it may even last several years after usage is stopped
• Adequate consumption of fruits and vegetables: A healthy diet, low in saturated fats and rich in many fruits and vegetables, may help decrease one’s risk for Primary Carcinoid Tumor of Uterus. Regular consumption of soy-based foods, incorporated into a diet, also decreases one’s risk
• The US Preventive Services Task Force (USPSTF) currently does not have any recommendation for screening against endometrial cancer for the general population. Tests, such as trans-vaginal ultrasonography and Pap smears, are not useful as screening tools
• The US-based National Cancer Institute (NCI) recommends that women, who are at an elevated risk for cancers of the endometrium, take regular (annual) examinations
• Early diagnosis with close monitoring and treatment of the tumor is important. A timely tumor recognition and prompt treatment will help in having optimal outcomes
• Regular medical screening at periodic intervals with blood tests, radiological scans, and physical examinations are mandatory. Often several years of active vigilance is suggested

What is the Prognosis of Primary Carcinoid Tumor of Uterus? (Outcomes/Resolutions)

• The prognosis of Primary Carcinoid Tumor of Uterus is generally excellent on a complete surgical excision and removal of the tumor
• In general, primary carcinoid tumor is very infrequently associated with an increased risk for endometrial cancer into the future. A healthcare provider will assess the risk depending on the combination of each individual’s risk factors
• Periodic follow-up check-ups with screening is recommended and essential

Note:

• The prognosis of primary atypical carcinoid tumor of uterus is generally excellent on a complete surgical excision and removal of the tumor, since in many cases they behave in a benign manner
• Atypical carcinoid tumors are infrequently associated with malignancy. In such cases, the prognosis of the tumor depends on the stage of the tumor, age of the individual, and treatment response, apart from other parameters

Additional and Relevant Useful Information for Primary Carcinoid Tumor of Uterus:

According to the World Cancer Research Fund International (WCRF International), endometrial cancer is the 6th most commonly diagnosed cancer in women. Also, each year, approximately around 350,000 new cases are diagnosed in women worldwide.