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

• Benign Stromal Nodule of Endometrium
• ESN (Endometrial Stromal Nodule)
• Uterine Endometrial Stromal Nodule

What is Endometrial Stromal Nodule? (Definition/Background Information)

• Endometrial Stromal Nodule (ESN) is an uncommon benign tumor of the uterus (uterine corpus). The tumor resembles the proliferative phase of the endometrial stroma, which represents the tissue between the endometrial glands
• The tumor is mostly present in middle-aged adult women, and both pre- and post- menopausal women may be affected. Currently, the risk factors for Endometrial Stromal Nodule are unidentified. The ESN tumors are known to be caused by genetic mutations and chromosomal aberrations
• The tumors may be painless and asymptomatic, in some cases. Some women may have pelvic pain and abnormal or heavy bleeding. Tumors that grow to large sizes can cause signs and symptoms due to compression of adjoining organ structures
• The treatment of choice for Endometrial Stromal Nodule is a surgical removal of the entire tumor. In most cases, the prognosis is excellent with appropriate treatment

Who gets Endometrial Stromal Nodule? (Age and Sex Distribution)

• Endometrial Stromal Nodule may be present in adult women of any age; women of a wide age group, between 23-86 years, may be affected
• But, it is mostly diagnosed in women in the 40-60 year’ age range (average age 53-54 years)
• There is no geographical, racial, or ethnic preference observed
• The incidence of Endometrial Stromal Nodule is about 2 cases per million women. Also, about 25% of the endometrial stromal tumors are ESNs

What are the Risk Factors for Endometrial Stromal Nodule? (Predisposing Factors)

• No specific risk factors are evident for Endometrial Stromal Nodule.

ESN is a type of endometrial stromal tumor. The following are the potential risk factors for endometrial stromal tumors:

• Tamoxifen therapy
• Unopposed estrogen therapy
• Polycystic ovarian syndrome (PCOS)

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 Endometrial Stromal Nodule? (Etiology)

The cause of development of Endometrial Stromal Nodule is related to genetic abnormalities. Currently, studies indicate defects in the following genes:

• JAZF1-SUZ12 fusion gene due to chromosomal translocation abnormality, namely t(7;17)(p21;q15)
• No abnormalities involving EPC1, PHF1, or MEAF6 genes are noted in Endometrial Stromal Nodules
  • Such mutations are present in low-grade endometrial stromal sarcomas (ESS)
  • Absence of these mutations help distinguish ESN from low-grade ESS

What are the Signs and Symptoms of Endometrial Stromal Nodule?

Some women may not show any signs and symptoms. In others, the signs and symptoms of Endometrial Stromal Nodule may include:

• The presence of a typically solitary tumor that can grow to large sizes
• The tumor size may range from 1 cm to 22 cm; average size of 7 cm
• The tumors are well-circumscribed and with clear borders
• In some cases, polypoid tumors, and rarely, cystic tumors are observed
• The tumors may be classified according to their location, and may be:
  • Intramural tumors, found within the uterine walls
  • Submucosal tumors, found in the thin tissues beneath the mucosal layers
• Enlarged uterus or feeling of a mass in the pelvic region
• The individual may have pain in the abdominal or pelvic region; large tumor masses may give rise to lower back pain
• Abnormal, heavy, or irregular uterine bleeding may be observed
• Signs and symptoms may also occur from large-sized tumors causing compression of adjoining uterine structures including frequent urination and lower back pain
• Tumor necrosis and hemorrhage is observed in some cases
• Infiltration due to ESN is minimal
• Pain during sexual intercourse

How is Endometrial Stromal Nodule Diagnosed?

The diagnosis of Endometrial Stromal Nodule may involve:

• Complete physical examination with thorough evaluation of medical history
• Ultrasound scan of the pelvis: It is a noninvasive procedure that uses high frequency sound waves to produce real-time images
• Abdominal and pelvic CT scan: It is a noninvasive procedure that provides more details of soft tissues, blood vessels, and internal organs
• Pelvic MRI scan: It is a noninvasive medical test that uses a powerful magnetic field to produce images of soft tissues, bones, organs, and all other internal structures of the abdomen and pelvis
• Blood tests that include:
  • Complete blood count (CBC) to detect the cause of anemia
  • Determination of estrogen/progesterone levels in blood
• Hysteroscopy: This procedure involves placing a probe through the cervix to examine the cavity of the uterus. This exam is helpful in detecting submucosal tumors
• Hysterosalpingography: It is usually performed in individuals with infertility. In this procedure, the structure of the uterus and fallopian tubes are studied by using a dye and X-ray images
• Needle biopsy of tumor: A needle biopsy may not be helpful, because one may not be able to visualize the different morphological areas of the tumor. Hence, a needle biopsy as a diagnostic tool has certain limitations, and an open surgical biopsy is preferred
• Open biopsy of tumor: A tissue biopsy is performed and sent to a laboratory for a pathological examination, who examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis

A differential diagnosis to eliminate the following tumor types is considered, before arriving at a definitive diagnosis of ESN:

• Cellular leiomyoma
• Low-grade endometrial stromal sarcoma (LGESS)
• Uterine tumor resembling ovarian sex cord tumor (UTROSCT)

Note:

• In many cases, Endometrial Stromal Nodule is an incidental diagnosis at the time of hysterectomy (surgical removal of the uterus)
• A dilation and curettage (D&C) of the uterus or an endometrial biopsy is not helpful in establishing a proper classification of ES tumors such as low-grade and high-grade endometrial stromal sarcomas
• Extensive sampling during a pathological examination can help exclude endometrial stromal sarcoma (ESS) or other malignancies
• If lymphovascular invasion is noted, then ESN is excluded from the diagnosis, since lymphovascular invasion can be observed in endometrial stromal sarcomas and not in Endometrial Stromal Nodules
• An ESN is generally well-circumscribed and does not invade into surrounding endometrial stroma. This helps distinguish an ESN from various types of ESS

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 Endometrial Stromal Nodule?

The possible complications of Endometrial Stromal Nodule include:

• Stress and anxiety due to fear of cancer of the uterus
• Infertility
• Heavy and prolonged menstrual bleeding may result in anemia
• Polypoid tumors may undergo mechanical injury, such as torsion or twisting, which can result in excruciating pain
• Such polyp-shaped tumors are known to cause cervical prolapse, in some cases
• Some tumors may grow to large sizes, and even grow out of the uterus affecting adjoining reproductive organs
• Recurrence of the tumor due to its partial or incomplete surgical removal

How is Endometrial Stromal Nodule Treated?

The following treatment methods may be employed for Endometrial Stromal Nodule:

• Asymptomatic or small-sized tumors may not require any treatment; in such cases, the healthcare provider may choose to periodically observe and monitor the tumor
• A simple surgical excision and removal of the entire tumor is normally sufficient treatment
• In women who have completed their family, a hysterectomy, which is the surgical removal of a part of or the entire uterus, may be undertaken
• Post-operative care is important: One must maintain minimum activity levels, until the surgical wound heals
• Follow-up care with regular screening and check-ups are important

How can Endometrial Stromal Nodule be Prevented?

Current medical research has not established a method of preventing Endometrial Stromal Nodule. However, the following general factors may be considered to reduce the risk for tumor development:

• Address any condition causing hormonal imbalance in the body
• Maintain weight through proper diet modification and physical exercises, if you are overweight/obese
• Avoid alcohol consumption or limit its intake
• Have a balanced diet that is not high in meat and low in vegetables; a balanced diet can also help avoid any mineral or vitamin deficiencies in the body
• Regular medical screening at periodic intervals with blood tests, radiological scans, and physical examinations are mandatory, due to risk of recurrence of the tumor. Often several years of active vigilance may be necessary

What is the Prognosis of Endometrial Stromal Nodule? (Outcomes/Resolutions)

• In many cases, the prognosis of Endometrial Stromal Nodule is generally excellent on surgical excision and removal of the tumor, since these are benign tumors
• The prognosis also depends on the size of the tumor - small tumors have generally better prognosis than larger tumors
• Also, large-sized tumors can cause infertility and may be difficult to remove surgically, without undertaking a hysterectomy. These factors may complicate the prognosis

Additional and Relevant Useful Information for Endometrial Stromal Nodule:

• Hysterectomy is a surgical procedure characterized by the surgical removal of the uterus

The following link will help you understand hysterectomy surgical procedure:

http://www.dovemed.com/common-procedures/procedures-surgical/hysterectomy-abdominal-with-salpingo-oophorectomy/