Uterine Polyps for the ABIM

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Uterine Polyps for the American Board of Internal Medicine Exam

Definition and Pathophysiology

Uterine polyps, or endometrial polyps, are benign overgrowths of endometrial tissue that project into the uterine cavity.
They are typically sessile or pedunculated and range in size from a few millimeters to several centimeters.
Polyps can occur as single or multiple growths and are composed of glands, stroma, and blood vessels.

Thought to arise from localized hyperplasia of endometrial glands and stroma.
Associated with hormonal factors, particularly estrogen, which stimulates endometrial growth.
Genetic alterations may also contribute, such as mutations in PTEN and beta-catenin pathways, which are linked to abnormal cellular proliferation.

Risk Factors

Age: Common in premenopausal and perimenopausal women, particularly between ages 40-50.
Hormonal Imbalance: Increased estrogen levels, especially with unopposed estrogen therapy, are linked to polyp formation.
Obesity: Higher estrogen production from adipose tissue raises the risk.
Hypertension and Tamoxifen Use: Tamoxifen, used in breast cancer treatment, is associated with increased polyp formation due to its partial estrogen agonist effect on the uterus.

Clinical Manifestations

The most common symptom, presenting as intermenstrual spotting, heavy menstrual bleeding (menorrhagia), or postmenopausal bleeding.
Irregular bleeding is especially common in premenopausal women.

Uterine polyps may interfere with sperm transport, embryo implantation, and overall uterine receptivity.
They are more often implicated in unexplained infertility, with hysteroscopic polypectomy potentially improving conception rates.

Asymptomatic: Many polyps are asymptomatic and incidentally discovered during evaluations for other conditions.

Diagnosis

A history of abnormal bleeding patterns, particularly spotting or intermenstrual bleeding, should raise suspicion for polyps.
Physical exam may reveal normal findings; however, polyps may occasionally be visible during cervical examination if they prolapse through the cervical os.

Transvaginal Ultrasound (TVUS): The preferred initial imaging modality to detect polyps. Polyps appear as focal, echogenic masses within the endometrial cavity. Fluid instillation (saline infusion sonohysterography, SIS) improves visualization of small polyps.
Hysterosonography: Injection of saline into the uterine cavity during ultrasound enhances visualization of endometrial polyps, providing high sensitivity and specificity.

Considered the gold standard for diagnosis, allowing direct visualization and biopsy of polyps.
Enables simultaneous diagnostic and therapeutic removal, especially for symptomatic or suspicious polyps.

May be used to rule out malignancy in high-risk patients, particularly postmenopausal women with bleeding.
Polyps are typically benign, but histopathologic examination is crucial to exclude hyperplasia or malignancy, especially if atypical features are present.

Differential Diagnosis

Leiomyomas (Fibroids): Benign smooth muscle tumors of the uterus that can also cause abnormal bleeding. Distinguishing features on ultrasound include shadowing, calcification, and a different echotexture compared to polyps.
Endometrial Hyperplasia: Overgrowth of endometrial glands that can mimic polyps on imaging, particularly if diffuse thickening is present.
Endometrial Cancer: Must be considered, especially in postmenopausal women with bleeding. Hysteroscopy or biopsy is essential for definitive diagnosis.

Management

Asymptomatic polyps, especially in premenopausal women, can often be observed if they are small and incidentally discovered.
Small polyps may spontaneously regress, and expectant management is reasonable if no symptoms are present.

Progestins: Used to reduce the size of polyps in cases where surgery is not feasible or preferred. However, response to medical therapy alone is limited.
Hormonal Modulation: Oral contraceptives or hormone therapy may control associated bleeding, though they do not resolve polyps.

Hysteroscopic Polypectomy: The treatment of choice for symptomatic polyps, polyps larger than 1 cm, or polyps in patients with infertility. Hysteroscopy allows for complete removal with direct visualization.
Polypectomy in Postmenopausal Women: Strongly recommended due to a higher risk of malignancy in postmenopausal patients. Any polyp with atypical features should be excised and sent for histopathology.
Endometrial Ablation or Hysterectomy: Considered in cases of recurrent polyps or concurrent endometrial pathology, such as hyperplasia or malignancy, in women who do not wish to preserve fertility.

Complications

Infertility: Polyps may impair fertility by obstructing sperm pathways, reducing endometrial receptivity, and hindering embryo implantation.
Malignant Transformation: Although rare, malignant transformation is more common in postmenopausal polyps and those with atypical features. Prompt removal and histopathologic examination of any suspicious polyp are essential.
Recurrence: Polyps may recur, especially in women with risk factors such as tamoxifen use or obesity. Repeated surgical removal may be required.

Prognosis

Benign Nature: Most uterine polyps are benign, and malignancy risk is generally low, though postmenopausal women have a higher risk.
Good Response to Treatment: Hysteroscopic removal of polyps is highly effective, with most patients experiencing symptom resolution.
Improved Fertility: Removal of polyps has been associated with improved fertility rates, particularly in women undergoing assisted reproductive techniques (ART).

Key Points

Uterine Polyps are benign overgrowths of endometrial tissue that project into the uterine cavity, often presenting with abnormal uterine bleeding, especially in perimenopausal women.
Pathophysiology involves localized endometrial hyperplasia influenced by hormonal factors, primarily estrogen, and genetic mutations affecting cellular proliferation.
Risk Factors: Advanced age, obesity, hypertension, tamoxifen use, and unopposed estrogen therapy increase the risk.
Symptoms: The most common presentation is abnormal uterine bleeding, with intermenstrual spotting, heavy menstrual bleeding, or postmenopausal bleeding. Polyps can also cause infertility or be asymptomatic.
Diagnosis relies on transvaginal ultrasound, saline infusion sonohysterography, and hysteroscopy. Hysteroscopy allows direct visualization, biopsy, and simultaneous removal, serving as the gold standard.
Management:

Observation is an option for asymptomatic, small polyps in premenopausal women.
Hysteroscopic Polypectomy is the treatment of choice for symptomatic, large, or suspicious polyps, particularly in postmenopausal women.
Medical therapy (e.g., progestins) is limited in efficacy, with hormonal therapy useful for controlling bleeding.

Complications: Although rare, malignant transformation risk is higher in postmenopausal women, making removal and histopathology essential for any suspicious or symptomatic polyp.
Prognosis is generally excellent with appropriate treatment, with symptom resolution and improved fertility outcomes following polyp removal.