Comparative study of frozen and permanent section for diagnosis of toxic epidermal necrolysis

Background Toxic epidermal necrolysis (TEN) is a severe, life-threatening mucocutaneous reaction, causing widespread sloughing of skin and mucosal surfaces. Accurate and prompt diagnosis is essential for optimal management and subsequent outcome. In this study, frozen sections were used as a rapid examination for initial diagnosis of TEN, and the frozen section diagnoses were assessed compared with permanent sections. Methods One hundred patients of suspected TEN were referred to our burn unit, and 67 had sufficient clinical findings for frozen and permanent biopsies. The accuracy of frozen section relative to permanent section was evaluated by calculating diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). And McNemar’s tests were used to analyze the difference between the two methods. Results Fifty-two specimens were classified as TEN by frozen section, 51 of which were confirmed by permanent biopsy. The exception was diagnosed as bullous pemphigoid on permanent section. Fifteen specimens were read as negative for TEN on frozen slides but 4 were changed to positive by permanent biopsy. Overall, the diagnostic accuracy of frozen section was 92.5%, with sensitivity and specificity 92.7% and 91.7% respectively. The positive predictive value, or coherence of positive diagnosis between the two methods, was as high as 98.1%, and the negative predictive value was 73.3%. The p-value of McNemar’s tests was 0.375, indicating there was no significant difference between the two biopsy methods. Conclusion The data suggest that as a rapid histological assessment, frozen section is a reliable tool in the early diagnosis of TEN.

Impact of intraoperative margin clearance on survival following pancreatoduodenectomy for pancreatic cancer: a systematic review and meta-analysis

The use of intraoperative margin revision to achieve margin clearance in patients undergoing pancreatoduodenectomy for pancreatic cancer is controversial. We performed a systematic review and meta-analysis to summarize the evidence of intraoperative margin revisions of the pancreatic neck and its impact on overall survival (OS). Nine studies with 4501 patients were included. Patient cohort was stratified in an R0R0-group (negative margin on frozen and permanent section), R1R0-group (revised positive margin on frozen section which turned negative on permanent section), and R1R1-group (positive margin on frozen and permanent section despite margin revision). OS was higher in the R1R0-group (HR 0.83, 95% CI 0.72–0.96, P = 0.01) compared to the R1R1-group but lower compared to the R0R0-group (HR 1.20; 95% CI 1.05–1.37, P = 0.008), respectively. Subgroup analyses on the use of different margin clearance definitions confirmed an OS benefit in the R1R0-group compared to the R1R1-group (HR 0.81; 95% CI 0.65–0.99, P = 0.04). In conclusion, intraoperative margin clearance of the pancreatic neck margin is associated with improved OS while residual tumor indicates aggressive tumor biology. Consensus definitions on margin terminologies, clearance, and surgical techniques are required.

Breast Sentinel Lymph Node Frozen Section Practice: An Enterprise Audit as a Guide for Moving Forward

Context.— In recent years, there has been a shift to less aggressive surgical management of the axilla in breast cancer. Consequently, sentinel lymph node evaluation by frozen section (FS) has declined. Additionally, there has been an impetus to decrease efforts in identifying small sentinel lymph node metastases. Objectives.— To critically evaluate our enterprise performance in evaluating axillary sentinel lymph node submitted for FS prior to considering changes in processing. Design.— A retrospective review (August 1, 2017–July 31, 2019) was conducted to identify sentinel and nonsentinel lymph nodes from 1 academic institution and 2 community sites. Cases were evaluated for grossing technique and discordance between FS and permanent section (PS) due to sampling and/or interpretive error. Clinicopathologic features were assessed. Results.— Lymph nodes from 426 patients with 432 neoplasms were sent for FS. Serial sectioning at 2-mm intervals was adhered to in 338 of 432 (78.2%). Serial sectioning was significantly lower at the community sites (14 of 60; 23.3%) versus at the academic institution (324 of 372; 87.1%; P < .001). Discordant cases were all false negatives (21 of 432; 4.8%). A total of 7 of 21 false negatives (33.3%) had macrometastatic (>2 mm) disease; of these, 3 were post–neoadjuvant chemotherapy, 3 were neither serially sectioned nor posttherapy, and 1 was a small (0.3-cm) focus. A total of 15 of 16 false negatives due to sampling error were detected on the first permanent section level. Conclusions.— Standard serial sectioning of sentinel lymph node at 2-mm intervals resulted in infrequent false negatives due to macrometastatic disease. A single additional permanent section level is reasonable, given adherence to serial sectioning.

Stimulated Raman histology for rapid and accurate intraoperative diagnosis of CNS tumors: prospective blinded study

OBJECTIVEIn some centers where brain tumor surgery is performed, the opportunity for expert intraoperative neuropathology consultation is lacking. Consequently, surgeons may not have access to the highest quality diagnostic histological data to inform surgical decision-making. Stimulated Raman histology (SRH) is a novel technology that allows for rapid acquisition of diagnostic histological images at the bedside.METHODSThe authors performed a prospective blinded cohort study of 82 consecutive patients undergoing resection of CNS tumors to compare diagnostic time and accuracy of SRH simulation to the gold standard, i.e., frozen and permanent section diagnosis. Diagnostic accuracy was determined by concordance of SRH-simulated intraoperative pathology consultation with a blinded board-certified neuropathologist, with official frozen section and permanent section results.RESULTSOverall, the mean time to diagnosis was 30.5 ± 13.2 minutes faster (p < 0.0001) for SRH simulation than for frozen section, with similar diagnostic correlation: 91.5% (κ = 0.834, p < 0.0001) between SRH simulation and permanent section, and 91.5% between frozen and permanent section (κ = 0.894, p < 0.0001).CONCLUSIONSSRH-simulated intraoperative pathology consultation was significantly faster and equally accurate as frozen section.