Endometriosis occurs when cells (called endometrial cells) that normally line the uterus grow in other places in a person’s body. The U.S. Office on Women’s Health reports endometriosis occurs in more than 11 percent of women between 15 and 44 years old. While endometriosis tissue growths mostly occur on a person’s ovaries, fallopian tubes, and the lining of the pelvis and abdomen, they can also affect the cervix.

Cervical endometriosis is exceedingly uncommon, however. For example, in one study, scientists reviewed past cases of endometriosis at Peking Union Medical Hospital in Beijing, China. They looked at the files of people with endometriosis who were treated at the hospital over a 27-year-span. From a pool of 13,566 people with endometriosis, they found 33 people had been diagnosed with cervical endometriosis.

Other studies show similar results, though the number of people studied are very small in comparison to the decades-long Beijing study. Given that cervical endometriosis is rare, the number of studies themselves is also small. Yet, there are people who experience the subtype. This article discusses cervical endometriosis, what it is, its signs, symptoms, causes, treatments, and more.

What Is Cervical Endometriosis?

Cervical endometriosis is endometriosis that occurs on your cervix. The cervix is the lower part of your uterus just above the uppermost part of your vagina. The cervix secretes mucus that protects the uterus from sperm during menstruation and throughout a pregnancy. It is the uterus’s exit pathway for menstruation and childbirth.

Signs of Cervical Endometriosis

People with cervical endometriosis typically don’t report having pain, the most common symptom of endometriosis on the whole. And other symptoms — including infertility and adhesions (bands of scar tissue that cause pelvic organs or structures to stick together) — that may be seen in other types of endometriosis are generally not at issue for people with cervical endometriosis. In the Beijing study, of the 33 people diagnosed with cervical endometriosis, 17 had abnormal vaginal bleeding or lesions in their cervixes that were visible.

Abnormal bleeding can be that which occurs after sexual intercourse or between periods (spotting). Spotting can persist for days or weeks. If it is heavy or frequent, spotting and other abnormal vaginal bleeding can lead a person to become anemic. Anemia is a shortage of red blood cells that leaves you tired and weak.

Cervical endometriosis can sometimes be discovered when a person is undergoing a pelvic exam, whether for endometriosis or for something unrelated and altogether different. (More typically, endometriosis in general is diagnosed with this chain of events: a person reports symptoms to their doctor, their doctor conducts a pelvic exam and determines a working diagnosis, then they perform a surgical exploration to confirm the presence of the condition.)

Symptoms of Endometriosis

When cervical endometriosis exists at the same time as endometriosis in other parts of the body, a person may experience classic endometriosis symptoms such as:

• Chronic pelvic pain
• Abdominal pain
• Back pain
• Heavy menstruation
• Painful menstrual periods
• Pain during sexual intercourse
• Pain during urination
• Pain during bowel movements
• Constipation
• Bloating
• Nausea
• Vomiting
• Infertility or difficulty getting pregnant

What Causes Cervical Endometriosis?

The root cause of endometriosis — and thus cervical endometriosis — is still undetermined, but it is generally thought to be influenced by both inherited genes and environmental factors. Risk factors for endometriosis include a family history of the condition and a person’s increased estrogen exposure. (Increased estrogen exposure can happen if you have your first period at a young age or if you begin menopause at a later age.)

Some research suggests that trauma to the cervix from surgery or vaginal delivery may play a role in the occurrence of cervical endometriosis. Of the 17 people with cervical endometriosis in the Beijing study, nearly 85 percent had either delivered a child vaginally or had had surgery related to their cervix. Another study concluded that HPV infection may contribute to endometriosis risk at large, but it didn’t single out cervical endometriosis specifically.

Diagnosis of Cervical Endometriosis

Cervical endometriosis can be found during a regular gynecologic pelvic exam. It can also be discovered after a hysterectomy has been performed. (A hysterectomy is the removal of a person’s entire uterus, including their cervix). Sometimes abnormal Pap smear results lead to the discovery of the condition.

If symptoms are present, diagnosing endometriosis may include collecting your medical history, having a physical examination, and taking blood tests. Diagnosis may also include imaging studies or a colposcopy exam and biopsy. Each of these steps and options are explained below.

Medical History

A careful and thorough medical history is important to identify symptoms of endometriosis and learn if your other family members have or have had endometriosis. Having family members with endometriosis increases your risk of developing endometriosis.

Physical Exam and Pelvic Exam

A physical exam can identify sites of pain, tenderness, or nodules that may be endometriosis lesions. A pelvic exam should include a speculum exam that allows your doctor to look at your cervix. If they see lesions of any kind there, they will need to biopsy (take a sample and test) the abnormal tissue.

Colposcopy and Biopsy

If your doctor finds abnormalities during your pelvic exam (through your Pap smear results, by sight, or otherwise), they will want to examine your cervix more closely. With a specialized microscope called a colposcope, your doctor can see your cervix in detail. This procedure is called a colposcopy, and it can aid your doctor to perform biopsies.

In a cervical biopsy, your doctor uses local (topical) anesthesia on your cervix, and collects the suspicious-looking tissue seen there. Typically, they attempt to remove an entire lesion rather than sample a portion of it. Tissue can be removed in cervical biopsies in different ways: with forceps, by scraping (called curettage), or with a thin, electrified wire loop (loop electrocautery). They then examine (or screen) the tissue for cancer and other conditions like cervical endometriosis. Biopsies can both diagnose and treat cervical endometriosis.

Blood Tests

Standard blood tests may also be needed to rule out other possible explanations of your symptoms, and to check for anemia.

Imaging

Imaging studies — such as pelvic and transvaginal ultrasounds — can help your doctor locate endometrial lesions. Computed tomography (CT) and magnetic resonance imaging (MRI) are sometimes used to identify suspected endometrial lesions. But CT and MRI are more likely to be used to look for structural abnormalities possibly associated with endometriosis.

Treatment of Cervical Endometriosis

The primary treatment for cervical endometriosis is surgical removal of the endometrial tissue, usually performed as part of biopsy of cervical lesions. After removal, there is a chance that endometriosis lesions will come back. A watch-and-wait approach is sometimes recommended when a person’s symptoms are not severe. Because cervical endometriosis is so rare, it is not clear what effect other endometriosis treatments, such as oral contraceptives (birth control), have on cervical endometriosis lesions.

Read more about treatments for endometriosis.

Talk With Others Who Understand

On MyEndometriosisTeam, the social network for people with endometriosis and their loved ones, nearly 124,000 members come together to ask questions, give advice, and share their stories with others who understand life with endometriosis.

Do you have cervical endometriosis? Share your experience in the comments below, or start a conversation by posting on MyEndometriosisTeam.