Back
ditki Logo
medical & biological sciences

Ovarian Cysts for USMLE Step 3

Start your One-Week Free Trial
Already subscribed? Log in »
Ovarian Cysts for the USMLE Step 3 Exam
  • Definition:
    • Ovarian cysts are fluid-filled sacs on or within an ovary. They are common and can be classified as functional (related to normal ovulation) or pathologic, with functional cysts being most frequent in reproductive-aged women.
  • Types of Ovarian Cysts:
Functional Cysts
Arising from the menstrual cycle, these typically resolve without intervention.
Follicular Cysts:
    • Form when a follicle fails to release an egg and continues to grow.
    • Usually asymptomatic and self-limiting, resolving within 1–3 menstrual cycles.
Corpus Luteum Cysts:
    • Develop if the corpus luteum does not regress after ovulation, filling with fluid or blood.
    • May cause pelvic pain or delayed menses, and usually resolve spontaneously.
Theca Lutein Cysts:
    • Associated with elevated hCG, as seen in pregnancy, molar pregnancies, or fertility treatments.
    • Usually resolve when hCG levels normalize.
Ovarian Cysts
Pathologic Cysts
Due to abnormal growth, these may require further evaluation, as they can be benign or malignant.
Dermoid Cysts (Mature Cystic Teratomas):
    • Contain germ cell derivatives (e.g., hair, skin, teeth).
    • Often asymptomatic but can cause pain if they undergo torsion or grow large.
Endometriomas:
    • Result from endometriosis, containing thick, dark blood (referred to as “chocolate cysts”).
    • Associated with chronic pelvic pain, dysmenorrhea, and infertility.
Cystadenomas:
    • Benign epithelial tumors that may be serous (thin fluid) or mucinous (thicker fluid).
    • Can grow large, causing abdominal discomfort or distension.
Clinical Presentation
  • Symptoms:
Many ovarian cysts are asymptomatic, found incidentally. Symptomatic cysts may present with: Pelvic Pain: Especially if the cyst is large, torsed, or ruptured. Menstrual Irregularities: Seen with some functional cysts. Acute Pain: Sudden, severe pain suggests complications like torsion or rupture.
  • Complications:
Ovarian Torsion:
    • Twisting of the ovary, usually with a large cyst, leading to acute pain, nausea, and vomiting.
    • Surgical intervention is necessary to prevent ischemic damage.
Cyst Rupture:
    • Causes sharp pelvic pain and may lead to intraperitoneal bleeding.
    • Symptoms include acute pain, with potential hemodynamic instability if bleeding is significant.
Diagnosis
  • Imaging:
Pelvic Ultrasound: First-line imaging to evaluate ovarian cysts.
    • Functional Cysts: Appear as simple, thin-walled, and unilocular.
    • Dermoid Cysts: May show echogenic material with calcifications.
    • Endometriomas: Display “ground-glass” echogenicity due to blood content.
    • Malignancy Indicators: Thick septations, irregular borders, solid areas, and ascites raise suspicion.
  • Laboratory Tests:
    • Serum hCG: Used to rule out pregnancy in reproductive-aged women.
    • CA-125:
    • A tumor marker often elevated in ovarian cancer, particularly in postmenopausal women.
    • May be nonspecifically elevated in benign conditions, such as endometriosis.
Management
Observation
Functional Cysts:
    • Often resolve on their own; simple cysts <5 cm in premenopausal women are usually monitored with repeat ultrasound in 1–3 months.
Postmenopausal Women:
    • Simple cysts <5 cm with normal CA-125 can be observed with serial ultrasound if there are no concerning features.
Medical Therapy
Hormonal Contraceptives:
    • Prevent the formation of new functional cysts, though they do not speed up the resolution of existing cysts.
    • Useful in women with recurrent functional cysts who also desire contraception.
Surgical Management
Indications for Surgery:
    • Persistent, symptomatic, or large cysts (>5–10 cm) and those with suspicious features on ultrasound.
    • Emergency surgery is required for complications like torsion or rupture.
Types of Surgery:
    • Cystectomy: Removal of the cyst alone, preserving ovarian tissue.
    • Oophorectomy: Removal of the ovary; often indicated for large or suspicious cysts, especially in postmenopausal women.
Key Points
  • Ovarian Cysts can be functional (e.g., follicular, corpus luteum) or pathologic (e.g., dermoid, endometrioma, cystadenoma).
  • Diagnosis primarily involves pelvic ultrasound, with CA-125 testing in postmenopausal women to assess malignancy risk.
  • Management involves observation for small, simple cysts, hormonal therapy for preventing recurrent functional cysts, and surgery for symptomatic, large, or suspicious cysts.
  • Complications like torsion and rupture present with acute abdominal pain and may require prompt surgical intervention.

Related Tutorials