Uterine Polyps for USMLE Step 3
Start your One-Week Free Trial
Already subscribed? Log in »
Uterine Polyps for the USMLE Step 3 Exam
Definition and Pathophysiology
- Definition
- Uterine polyps are benign growths of endometrial tissue projecting into the uterine cavity, composed of endometrial glands, stroma, and blood vessels.
- They can vary in size and may be pedunculated (stalked) or sessile (flat).
- Pathophysiology
- Polyps arise from focal overgrowths of the endometrial glands and stroma, influenced by estrogen.
- Genetic mutations, such as PTEN and beta-catenin pathway abnormalities, may contribute to their formation by promoting abnormal cellular proliferation.
Risk Factors
- Age: Higher prevalence in perimenopausal and postmenopausal women, typically between ages 40-50.
- Estrogen Exposure: Increased levels, especially unopposed estrogen or tamoxifen therapy, can raise risk.
- Obesity: Associated with elevated peripheral estrogen production in adipose tissue.
- Hypertension: Some studies suggest a link between hypertension and polyp formation, though mechanisms are unclear.
Clinical Manifestations
- Abnormal Uterine Bleeding (AUB):
- The most common symptom, often presenting as intermenstrual spotting, heavy menstrual bleeding, or postmenopausal bleeding.
- Bleeding is particularly common in perimenopausal women and may require evaluation for underlying causes.
- Infertility:
- Polyps can interfere with sperm transport, embryo implantation, or overall endometrial receptivity, contributing to infertility.
- Removal of polyps (polypectomy) has been shown to improve fertility rates.
- Asymptomatic: Many polyps are incidentally found during imaging or evaluations for unrelated symptoms.
Diagnosis
- Clinical History and Physical Examination:
- AUB, especially with irregular spotting, should prompt further evaluation.
- Physical exam is often normal, as polyps are usually located within the uterine cavity.
- Imaging:
- Transvaginal Ultrasound (TVUS): The preferred initial imaging tool; polyps appear as echogenic masses within the endometrium.
- Saline Infusion Sonohysterography (SIS): Infusing saline during ultrasound enhances visualization, aiding in the detection of smaller polyps.
- Hysteroscopy:
- Gold standard for diagnosis, providing direct visualization and biopsy capability.
- Enables concurrent removal of polyps, which is particularly useful for symptomatic or suspicious growths.
Differential Diagnosis
- Leiomyomas (Fibroids): Uterine smooth muscle tumors that can cause abnormal bleeding but typically appear differently on ultrasound.
- Endometrial Hyperplasia: Diffuse thickening of the endometrial lining, often due to unopposed estrogen exposure.
- Endometrial Cancer: Especially relevant in postmenopausal women with bleeding; biopsy or hysteroscopy is required for definitive diagnosis.
Management
- Observation:
- Small, asymptomatic polyps in premenopausal women may not require immediate intervention and can be monitored.
- Medical Management:
- Hormonal Therapy: Combined oral contraceptives or progestins can control bleeding but do not eliminate polyps.
- Surgical Management:
- Hysteroscopic Polypectomy: The primary treatment for symptomatic polyps, polyps larger than 1 cm, or polyps in patients with infertility or postmenopausal bleeding.
- Polypectomy in Postmenopausal Women: Recommended to mitigate the small but present risk of malignant transformation.
Key Points
- Uterine Polyps are benign endometrial overgrowths that can cause abnormal uterine bleeding and infertility, particularly in perimenopausal and postmenopausal women.
- Pathophysiology: Driven by estrogen exposure, with potential genetic factors influencing proliferation.
- Risk Factors: Advanced age, unopposed estrogen, obesity, tamoxifen use, and hypertension.
- Symptoms: Commonly present with abnormal bleeding, including intermenstrual spotting and postmenopausal bleeding. Many polyps are asymptomatic.
- Diagnosis: Based on transvaginal ultrasound and saline infusion sonohysterography, with hysteroscopy as the gold standard for confirmation and treatment.
- Management:
- Observation for asymptomatic, small polyps in premenopausal women.
- Hysteroscopic Polypectomy for symptomatic, large, or suspicious polyps, especially in postmenopausal patients.
- Complications: Malignant transformation is rare but more common in postmenopausal women, justifying removal and histopathology for suspicious cases.