Pancreatic Endometriosis

Overview

Pancreatic endometriosis is a condition where tissue resembling the lining of the uterus, or the endometrium grows in and around the pancreas. It can occur with or without classical endometriosis (1).

About the pancreas

The pancreas is an organ situated in the abdomen whose role is to produce digestive enzymes and hormones that regulate blood sugar (2). It is surrounded by other organs such as the stomach, small intestine, liver, spleen, and gallbladder (3).

How does endometriosis affect the pancreas?

Endometriosis is characterized by tissue resembling the endometrium to grow outside the uterus and form cysts. It usually occurs in and around pelvic organs close to the uterus such as the ovaries and the fallopian tubes (the tubes connecting the ovaries to the uterus). However, in rare cases, endometriosis can also occur in other organs and tissues such as the kidneys (4), appendix (5), pancreas, and even lungs (6).

In pancreatic endometriosis, the extrauterine tissue can lead to pancreatitis or the inflammation of the pancreas (7). It can also form cysts that may bleed, usually in synchrony with the menstrual cycle and cause pain or disrupt the function of the pancreas. Sometimes, scar tissue can form around the cysts and further disrupt the function of the pancreas (1).

What is the prevalence of pancreatic endometriosis?

Pancreatic endometriosis is very rare with only a few cases reported in the literature. The first cases were reported in 1984 by a group of researchers at The Mount Sinai School of Medicine in New York (8).

The condition has been reported in women ages, 21 to 68 who were still menstruating or in menopause (1).

Causes

What causes pancreatic endometriosis?

Like classical endometriosis, it is not known what causes pancreatic endometriosis. Some researchers think that retrograde menstruation or the back flow of menstrual blood up the fallopian tubes could carry stem cells from inside the uterus to other areas, like the pancreas, where they implant and form endometrial lesions (the stem cell theory of endometriosis) (9).

Symptoms

What are the symptoms of pancreatic endometriosis?

Symptoms of pancreatic endometriosis include:

• Abdominal pain that usually coincides with the menstrual cycle
• Digestive problems including vomiting and diarrhea
• Nausea and weight loss
• Fatigue

Diagnosis

How is pancreatic endometriosis diagnosed?

Pancreatic endometriosis is difficult to diagnose as it is so rare. Imaging tests and needle-guided biopsy can be used to diagnose the condition. The patient’s previous medical history such as the presence of classical endometriosis or pancreatitis can also be useful in reaching a diagnosis (1).

Imaging tests to diagnose pancreatic endometriosis

The imaging tests used to diagnose pancreatic endometriosis include ultrasound, magnetic resonance imaging (MRI), and computed tomography (CT).

Ultrasound uses high-frequency sound waves to produce an image of the internal organs (10).

MRI is a non-invasive technique in which detailed three-dimensional images of internal organs are produced using strong magnets (11).

CT uses X-ray images taken from different angles and combines them with the aid of a computer to create detailed images of internal organs as well as bones and blood vessels (12).

None of these imaging techniques is sensitive enough to be able to detect all endometrial lesions and differentiate between endometrial cysts and cancerous ones, however.

Biopsy

A pancreatic tissue biopsy obtained from around the lesions and observed under the microscope can help identify the nature of the lesions. However, this is a more invasive approach compared to imaging techniques.

Treatment

The pain caused by pancreatic endometriosis can be managed with non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and naproxen, or opioid narcotics in cases of severe pain. It is important to remember that opioids are highly addictive and should only be used if prescribed by a healthcare professional and not for extended periods of time.

Other medications that can alleviate the pain caused by pancreatic endometriosis include hormonal treatments like gonadotrophin-releasing hormone (GnRH) receptor agonists and antagonists and hormonal contraceptives.

The surest method of treating endometriosis of the pancreas, especially if it is not clear whether or not the cysts are cancerous, is to remove the affected and surrounding tissues with resection surgery.

References

1. Where Is The Pancreas And What Does It Do? - extrapelvicnotrare.org
2. Diagnosis, Prevention, and Treatment for All Pancreatic Condition, Colombia Surgery
3. What Is The Pancreas? - Pancreatic Cancer Action Network
4. Can endometriosis affect the kidneys? - drseckin.com
5. What is appendiceal endometriosis? - drseckin.com
6. Thoracic Endometriosis - drseckin.com
7. Pancreatitis - Mayo Clinic
8. Endometrial Cyst of the Pancreas - gastrojournal.org
9. Causes Of Endometriosis: Several Proposed Theories - drseckin.com
10. Ultrasound - Medline Plus
11. Magnetic Resonance Imaging (MRI) - nibib.nih.gov
12. CT scan - Mayo Clinic