Ovarian Cysts for ABIM
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Ovarian Cysts for the American Board of Internal Medicine Exam
- Definition:
- Ovarian cysts are fluid-filled sacs or pockets within or on the surface of an ovary. They are commonly classified as functional or pathologic, with functional cysts being the most frequent type in reproductive-aged women.
- Types of Ovarian Cysts:
Functional Cysts
- Functional cysts are benign and related to the normal ovulatory cycle, typically resolving on their own.
- Follicular Cysts:
- Occur when a follicle fails to rupture and release an egg.
- Usually asymptomatic and self-limiting, resolving within one to three menstrual cycles.
- Corpus Luteum Cysts:
- Form after ovulation if the corpus luteum seals and fills with fluid instead of degenerating.
- These cysts may cause pain and are associated with delayed menses or heavy bleeding.
- Theca Lutein Cysts:
- Less common, often associated with high levels of human chorionic gonadotropin (hCG).
- Occur in molar pregnancies, multiple gestations, and fertility treatments and typically resolve once hCG levels normalize.
Pathologic Cysts
- Pathologic cysts arise from abnormal cell growth and may be benign or malignant, requiring further investigation.
- Dermoid Cysts (Mature Cystic Teratomas):
- Arise from germ cells and contain a variety of tissue types (e.g., hair, skin, teeth).
- Typically asymptomatic but can cause pain if they undergo torsion.
- Endometriomas:
- Caused by endometriosis and filled with thick, dark blood (often called “chocolate cysts”).
- Associated with pelvic pain, dysmenorrhea, and dyspareunia (painful intercourse).
- Cystadenomas:
- Benign epithelial tumors that can be serous or mucinous.
- May grow large and cause abdominal distension or pain.
- Malignant Ovarian Cysts:
- May include serous or mucinous cystadenocarcinomas, clear cell carcinomas, and other malignant tumors.
- More common in postmenopausal women and require prompt evaluation.
Clinical Presentation
- Symptoms:
- Most ovarian cysts are asymptomatic and discovered incidentally during imaging.
- Pain: May present as pelvic pain, especially if the cyst is large, undergoes torsion, or ruptures.
- Menstrual Irregularities: May be observed with certain types of functional cysts.
- Acute Pain: Sudden, severe pain typically suggests complications like hemorrhage or ovarian torsion.
- Complications:
- Ovarian Torsion:
- Twisting of the ovary around its ligamentous supports, often due to a large cyst or mass.
- Presents with sudden-onset, severe unilateral pelvic pain, nausea, and vomiting.
- Requires prompt diagnosis and surgical intervention to preserve ovarian function.
- Cyst Rupture:
- Can cause acute abdominal pain and internal bleeding.
- Symptoms include sudden, sharp pelvic pain, often with some degree of intra-abdominal bleeding.
Diagnosis
- Imaging Studies:
- Pelvic Ultrasound: Primary imaging modality to characterize ovarian cysts.
- Functional Cysts: Typically unilocular and thin-walled on ultrasound.
- Dermoid Cysts: May show echogenic material, including hair or calcifications.
- Endometriomas: Characteristic ground-glass echogenicity due to thickened blood.
- Malignant Features: Include solid areas, thick septations, irregular borders, and ascites.
- CT or MRI:
- Used for further evaluation when ultrasound findings are indeterminate or suggest malignancy.
- Laboratory Tests:
- Serum hCG: To rule out pregnancy, particularly in reproductive-aged women with an ovarian mass.
- CA-125:
- A tumor marker that can be elevated in ovarian malignancies, particularly epithelial ovarian cancer.
- CA-125 levels can also be elevated in benign conditions (e.g., endometriosis, pelvic inflammatory disease), so it is more useful in postmenopausal women.
Management
Observation
- Functional Cysts:
- Often resolve spontaneously and do not require intervention.
- For cysts <5 cm in premenopausal women, observation with repeat ultrasound in 1-3 months is typically recommended.
- Postmenopausal Women:
- Cysts <5 cm that are simple and unilocular may be observed with serial imaging if CA-125 levels are normal and there are no concerning features.
Medical Therapy
- Hormonal Contraceptives:
- May prevent the formation of new functional cysts, though they do not hasten the resolution of existing cysts.
- Useful in women with recurrent functional cysts and those desiring contraception.
Surgical Intervention
- Indications:
- Large cysts (>5-10 cm), symptomatic cysts, or cysts with concerning features on imaging.
- Immediate surgery for cysts causing acute symptoms due to rupture or torsion.
- Types of Surgery:
- Cystectomy: Removal of the cyst alone, preserving ovarian tissue, especially in younger patients.
- Oophorectomy: Removal of the affected ovary; may be indicated for large or suspicious cysts, particularly in postmenopausal women.
Management of Specific Types of Cysts
- Dermoid Cysts:
- Elective cystectomy is often recommended, as these cysts have a risk of torsion and may grow over time.
- Endometriomas:
- Surgical removal (cystectomy) may be considered for large or symptomatic cysts, especially if they impact fertility.
- Hormonal therapy can manage symptoms and reduce recurrence, but definitive removal is often required for severe cases.
- Malignant Cysts:
- Require prompt referral to gynecologic oncology for surgical staging and treatment, which may include oophorectomy, hysterectomy, and chemotherapy, depending on the stage and type of cancer.
Prevention
- Screening:
- Routine screening for ovarian cysts is not recommended in asymptomatic, average-risk women.
- In high-risk women (e.g., BRCA mutation carriers), prophylactic oophorectomy may be considered due to an increased risk of ovarian cancer.
Key Points
- Ovarian Cysts can be classified as functional (e.g., follicular, corpus luteum) or pathologic (e.g., dermoid, endometrioma, cystadenoma, and malignant cysts).
- Clinical Presentation varies from asymptomatic findings to acute abdominal pain if complications (e.g., torsion, rupture) occur.
- Diagnosis relies on ultrasound imaging, which helps characterize the cyst; CA-125 levels are particularly useful in postmenopausal women when malignancy is a concern.
- Management includes observation for simple, small functional cysts, hormonal therapy for prevention, and surgery for symptomatic or suspicious cysts.
- Complications of ovarian cysts include torsion, cyst rupture, and hemorrhage, which may present as acute abdomen and require surgical management.