Frozen Section in Ovarian Tumor Removal
Frozen section should be performed during ovarian tumor surgery to guide the extent of surgical staging and resection, as it allows real-time determination of whether comprehensive staging procedures (including lymphadenectomy) are needed. 1
Primary Role and Clinical Utility
Frozen section enables intraoperative decision-making about the extent of surgery required, particularly determining whether:
- Comprehensive surgical staging with lymphadenectomy is necessary 1
- Fertility-sparing surgery is appropriate for young women desiring preservation 1
- Radical cytoreductive procedures should be performed 1
The technique has high overall accuracy (97-99%) for distinguishing benign, borderline, and malignant ovarian tumors. 2, 3, 4
Performance Characteristics
For Benign Tumors
- Sensitivity: 95-100% 2, 3, 4
- Specificity: 97-100% 2, 3, 4
- Frozen section reliably identifies benign lesions, preventing unnecessary radical surgery 3, 4
For Malignant Tumors
- Sensitivity: 84-96% 2, 3, 4
- Specificity: 94-100% 2, 3, 4
- Post-test positive probability of 95% when frozen section suggests cancer requiring lymph node staging 5
- When frozen section indicates malignancy requiring comprehensive staging, this diagnosis is highly reliable and should guide immediate surgical management 5
For Borderline Tumors
- Sensitivity: 50-89% (significantly lower than other categories) 2, 3, 4, 6
- Specificity: 85-98% 2, 3, 4
- This is the major limitation of frozen section 1
Critical Limitations and Pitfalls
Diagnostic Challenges
The main limitation is distinguishing very well-differentiated adenocarcinomas from borderline tumors, which requires close collaboration between surgeon and pathologist. 1
Mucinous tumors are particularly problematic on frozen section, with higher rates of misdiagnosis compared to other histologic types. 3, 6
Under-diagnosis occurs more frequently than over-diagnosis, particularly:
- Borderline tumors may be called benign 2, 3
- When frozen section suggests only peritoneal staging is needed, malignancy is underestimated in 44% of cases 5
Technical Factors Affecting Accuracy
- Large ovarian lesions (>8-10 cm) reduce diagnostic accuracy 1
- Inadequate sampling contributes to errors—multiple blocks (1-5 depending on tumor size) should be examined 2
- Pathologist expertise matters: Gynecologic pathologists achieve higher accuracy (97.1% overall) compared to general pathologists, particularly for borderline tumors (89.5% vs 50% sensitivity) 6
When Frozen Section Should Be Used
Frozen section should only be performed when the surgical strategy would be altered by the result, such as deciding whether to proceed with:
- Nodal staging procedures 1
- Radical cytoreductive surgery 1
- Fertility-sparing versus comprehensive surgery 1
Frozen section is essential for fertility-sparing decisions in young women, as it determines whether unilateral salpingo-oophorectomy alone is appropriate or if more extensive surgery is required. 1, 7
Specimen Handling Requirements
The excised tissue must be transported intact and unopened to the laboratory as rapidly as possible to maintain diagnostic quality. 1
A medical summary with clinical details must accompany the specimen, as interpretation requires knowledge of patient age, imaging findings, and clinical presentation. 1
Meticulous macroscopic examination must precede histological analysis, with attention to tumor size, laterality, capsule integrity, and presence of solid components. 1
Avoiding Common Errors
Do not biopsy a normal-appearing contralateral ovary during fertility-sparing surgery unless there is visible suspicion of involvement, as this can cause unnecessary ovarian damage. 7
Avoid tumor rupture during removal, as spillage alters FIGO staging from IA to IC and worsens prognosis—this risk is potentially increased with minimally invasive approaches. 1
When frozen section is indeterminate or deferred, proceed with comprehensive staging rather than conservative surgery, as under-staging leads to missed malignancy in approximately 30% of cases. 8
Recognize that negative frozen section does not exclude malignancy—if clinical suspicion remains high (elevated CA-125, imaging findings, intraoperative appearance), proceed with appropriate staging procedures. 5