Stromal endometriosis is a term used to specify the nature of tissue present in endometriosis. A diagnosis featuring this type of cell could mean endometrial lesions are more challenging to spot within your body.

Stromal endometriosis describes endometriosis tissue made primarily of stromal cells. Stromal cells make up the connective infrastructure of all organs in your body.

In the lining of your uterus, the endometrium, stromal cells exist within both the functional layer that sheds during menstruation and the basal layer that triggers regeneration of the functional layer.

Conventional endometriosis consists mainly of glandular cells, the cells that dominate the makeup of your epithelial lining, the topmost layer of the endometrium. In stromal endometriosis, stromal cells are the predominant cell type.

Limited research exists on stromal endometriosis, and its exact prevalence is unknown. Older research from 2009 suggests that while stromal endometriosis is under-recognized, it may be a common presentation of endometriosis, accounting for as many as 44% of people reviewed.

As a tissue variation rather than a subtype, the symptoms of stromal endometriosis are similar to those of conventional endometriosis.

Stromal tissue will respond to hormone fluctuations in your body just as glandular cells do.

Symptoms of endometriosis include:

  • chronic pelvic pain
  • pain during penetration
  • abnormal menstrual bleeding
  • infertility

Because endometriosis can develop almost anywhere in your body, pain can be specific to lesion sites.

If you have endometriosis on your bladder, for example, you may notice pain when urinating or experience symptoms that feel like a bladder infection.

Some people live with endometriosis but don’t experience symptoms.

The causes of endometriosis aren’t fully understood, but several theories exist.

The most widely accepted is that of retrograde menstruation, where endometrial tissue backflows through your fallopian tubes into your pelvic cavity, allowing for the endometrial cells to spread.

Another theory involves differentiating certain cell types into endometrial-like tissue due to genetic or hormonal triggers. A third theory is that it’s caused by the failure of your immune system to eliminate inappropriate endometrial cells outside of your uterus.

Why stromal endometriosis may develop instead of conventional endometriosis isn’t clear. But recent research, such as a review from 2021, suggests stromal cells may spark unique interactions with immune cells.

These distinctive interactions potentially contribute to immune dysfunction and tumor development processes across various conditions.

Surgery is the only way to diagnose any form of endometriosis definitively. Your healthcare professional does this through laparoscopy, or “keyhole” surgery.

Laparoscopy involves making a small incision in your abdomen that’s just large enough to insert a specialized viewing tool called a laparoscope. A doctor uses the scope to examine the surface areas of your reproductive organs and other structures inside your abdominal cavity.

Conventional endometriosis almost always has a distinct appearance specific to uterine gland tissue. It appears in varying color shades, involves a spectrum of cellular makeups, and can occur at multiple depths within tissue.

Stromal endometriosis may not have the classic glandular appearance, making it less obvious on visual assessment.

Stromal endometriosis is treated using the same methods as conventional endometriosis. A healthcare professional will recommend treatment based on your symptoms, where the endometriosis has developed, and the presence of any coexisting conditions.

Some cases of endometriosis can be treated with hormone therapy, such as oral contraceptives or the placement of an intrauterine device (IUD). A doctor may recommend this first-line option if your symptoms are mild or endometriosis is in a difficult-to-reach area of your body.

Different hormone therapies are available based on whether or not you’re planning on pregnancy.

For moderate to severe endometriosis, or if fertility is trying to be regained, surgery is the primary option. A surgeon can remove endometriosis lesions and adhesions — bands of scar tissue — with the same laparoscopic methods used during diagnosis.

In extreme cases, laparotomy or open surgery may be necessary to remove endometriosis fully.

If you aren’t experiencing symptoms, a healthcare professional may recommend monitoring your condition rather than actively starting treatment.

Endometriosis is treatable, though up to 80% of people report a recurrence of pain within 2 years of surgery. Medications and hormone therapy can help extend the time you remain pain free.

Ultimately, endometriosis isn’t considered a fatal condition. But if it’s left untreated, it can lead to life threatening complications like ectopic pregnancy or small bowel obstruction.

Although considered very rare, older research indicates it’s possible for endometriosis to lead to the development of endometrial stromal sarcoma, a type of cancer originating from the stromal cells of your endometrium.

According to the American Cancer Society, the combined 5-year survival rate for any stage of low-grade endometrial stromal sarcoma is 96%. But the high-grade endometrial stromal sarcoma survival rates dip to around 43%.

What are endometrial stromal cells?

Endometrial stromal cells are connective tissue cells found throughout your endometrium, the lining of your uterus.

What are endometrial stromal tumors?

Endometrial stromal tumors are growths originating from stromal cells in your endometrium.

Can endometrial stroma be benign?

The endometrial stroma is the framework of connective tissue found beneath the epithelial lining of your endometrium. It’s a natural part of your uterus and is benign.

Tumors that grow within the endometrial stroma may be benign or cancerous.

What’s the difference between endometrial stromal tumors and stromal endometriosis?

Endometrial stromal tumors are bundles of excessive cell growth originating within the uterine lining inside your uterus.

Stromal endometriosis develops outside of your uterus and is defined as endometrial-like lesions on pelvic or abdominal structures.

Stromal endometriosis is a descriptive term for the specific cellular makeup of endometriosis tissue. It’s not a formal subtype of the disease and is diagnosed and treated in the same ways as conventional endometriosis.

While limited research exists on stromal endometriosis, it may be relatively common but under-recognized. Due to its unique cellular makeup, it might also be less obvious during visual examinations.

The same hormone therapy and surgery used for conventional endometriosis can also treat stromal endometriosis.