Laboratory Testing for a 15-Year-Old with Complex Ovarian Cyst
In a 15-year-old female with a complex ovarian cyst, measure CA-125, alpha-fetoprotein (AFP), and beta-hCG before any surgical intervention. 1
Primary Tumor Markers Required
CA-125
- CA-125 should be measured in all patients with suspected ovarian pathology before surgery, regardless of age. 1
- The normal threshold is ≤35 U/mL, though this marker has critical limitations in adolescents 1, 2
- CA-125 is elevated in only 50% of stage I ovarian cancers, so a normal level does not exclude malignancy 1, 2
- In premenopausal women (including adolescents), CA-125 can be falsely elevated by menstruation, endometriosis, and pelvic inflammatory disease 2
Germ Cell Tumor Markers (Critical in Adolescents)
- Alpha-fetoprotein (AFP) and beta-hCG must be measured in all women under age 35 with ovarian masses to exclude germ cell tumors. 1
- Germ cell tumors are the most common malignant ovarian neoplasms in adolescents and young women, making these markers essential in this age group 1
Additional Marker When CA-125 is Normal
- Measure CA 19-9 if CA-125 is normal and imaging suggests clear cell, mucinous, or endometrioid features 1
Integration with Imaging
- Never interpret tumor markers in isolation—always correlate with transvaginal or transabdominal ultrasound findings with color Doppler. 1, 2
- Ultrasound is superior to CA-125 alone for distinguishing benign from malignant lesions 3, 1
- If imaging shows an indeterminate mass with elevated markers, MRI with IV contrast is the next step for characterization 1
Critical Pitfalls to Avoid
- Do not rely on CA-125 alone to make surgical decisions, as it lacks sufficient sensitivity for early disease 1
- Do not assume a normal CA-125 excludes ovarian cancer, particularly in premenopausal patients or early-stage disease 1, 2
- Do not forget AFP and beta-hCG in young patients—this is the most common error in adolescent ovarian mass workup 1
- Do not order CA-125 as an initial screening test without ultrasound correlation 2
Clinical Context
- At age 15, the most common ovarian neoplasm is a benign cystic teratoma (dermoid), which can be diagnosed by ultrasound in most cases 3
- However, malignant germ cell tumors, while rare, occur in this age group and require the specific markers (AFP, beta-hCG) for detection 1
- The combination of all three markers (CA-125, AFP, beta-hCG) with ultrasound provides the best preoperative assessment 1, 4