Intraoperative Surgical Margin Clearance - Correlation of Touch Imprint Cytology, Frozen Section Diagnosis, and Histopathological Diagnosis

Diagnostic accuracy of intraoperative frozen section for margin evaluation of oral cavity squamous cell carcinoma

OBJECTIVES

Intraoperative frozen-section evaluation is a valuable technique for detecting positive margins intraoperatively for oral squamous cell carcinoma. We conducted this study to determine the diagnostic accuracy of frozen section in detecting margin status and the effect of tumor grade and stage on diagnostic accuracy.

RESULTS

A total of 251 biopsy-proven cases of oral squamous cell carcinoma were included in this study. The tissue specimen resected during surgery was sent to the laboratory for frozen section evaluation. The frozen section results were then compared with the permanent section results to determine the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy. The mean age of the patients included in the study was 51.65 ± 10.03 years, with male predominance (55.4%). The overall sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of frozen section were 88.81%, 94.84%, 95.20%, 88.10%, and 91.63%, respectively. We conclude that frozen section is a useful technique in determining the margin status intraoperatively in oral cancers, with high diagnostic accuracy. Moreover, certain clinical parameters such as age, gender, disease duration, and tumor stage and grade appear to affect the diagnostic accuracy of frozen section.

Role of Intraoperative Pathology Consultation by Imprint and Scrape Cytology in Soft Tissue Tumors and Tumor-Like Lesions

Intraoperative pathologic consultation plays an essential role in therapeutic decision making, possibly avoiding under or overtreatment of the patient. Common indications for intraoperative consultation include obtaining a diagnosis in an unknown pathology, ruling out malignancy, confirming a provisional diagnosis, and assessing margin status. Fifty patients undergoing surgery for soft tissue tumors or tumor-like lesions were included in the present prospective study to evaluate the role of intraoperative pathologic consultation by imprint and scrape cytology. Careful and quick gross examination of the specimen was performed, followed by processing for imprint and scrape smears. The prepared smears were evaluated by three pathologists and the cytological diagnosis compared subsequently with final histopathological diagnosis. Intraoperative consultation was primarily requested to make or confirm preoperative diagnosis. In 44.0% cases, no previous tissue/cytological diagnosis was available. In 56.0% cases, previous pathological diagnosis was available, but the reports were inconclusive or were reported from outside our institute. The diagnostic yield of imprint smears was 24% (5 malignant, 6 benign, and 1 inconclusive), and scrape smears was 100% (10 malignant, 38 benign, and 2 inconclusive). Paraffin-embedded sections yielded diagnosis in 100% cases (11 malignant, 38 benign, and 1 nonneoplastic). Imprint smears alone were not of much help in intraoperative diagnosis. Scrape smears were found to be superior to imprint smears in terms of diagnostic yield and accuracy. Combined imprint and scrape smear cytology did not provide any advantage in intraoperative provisional tissue diagnosis in soft tissue tumors.