Tumor spread through air spaces in lung cancer: prospective analysis of the accuracy of intraoperative frozen section examination.

OBJECTIVE: To establish the accuracy of frozen section examination in identifying tumor spread through air spaces (STAS), as well as to propose a reproducible technical methodology for frozen section analysis. We also aim to propose a method to be incorporated into the decision making about the need for conversion to lobectomy during sublobar resection. METHODS: This was a nonrandomized prospective study of 38 patients with lung cancer who underwent surgical resection. The findings regarding STAS in the frozen section were compared with the definitive histopathological study of paraffin-embedded sections. We calculated a confusion matrix to obtain the positive predictive value (PPV), negative predictive value (NPV), sensitivity, specificity and accuracy. RESULTS: The intraoperative frozen section analysis identified 7 STAS-positive cases that were also positive in the histopathological examination, as well as 3 STAS-negative cases that were positive in the in the histopathological examination. Therefore, frozen section analysis was determined to have a sensitivity of 70%, specificity of 100%, PPV of 100%, NPV of 90.3%, and accuracy of 92% for identifying STAS. CONCLUSIONS: Frozen section analysis is capable of identifying STAS during resection in patients with lung cancer. The PPV, NPV, sensitivity, and specificity showed that the technique proposed could be incorporated at other centers and would allow advances directly linked to prognosis. In addition, given the high accuracy of the technique, it could inform intraoperative decisions regarding sublobar versus lobar resection.

Development and validation of a predictive model for assessing the risk of follicular carcinoma in thyroid nodules identified as suspicious by intraoperative frozen section.

Introduction: Follicular thyroid carcinoma (FTC) is the second most common thyroid malignancy and is characterized by a higher risk of distant metastasis compared to papillary thyroid cancer. Intraoperative frozen section (IOFS) diagnosis of FTC is challenging due to its limited sensitivity and accuracy, leading to uncertainty in intraoperative surgical decision-making. In response, we developed a predictive model to assess the risk of follicular carcinoma in thyroid nodules identified as suspicious for follicular neoplasm by IOFS. Methods: This model was derived from preoperative clinical and ultrasound data of 493 patients who underwent thyroid surgery at Ningbo Medical Center Lihuili Hospital. It identified five significant predictors of follicular carcinoma: nodule size, thyroglobulin (Tg) level, hypoechogenicity, lobulated or irregular margins, and thick halo. Results: The model demonstrated robust discrimination and calibration, with an area under the curve (AUC) of 0.83 (95% CI: 0.77-0.90) in the training set and 0.78 (95% CI: 0.68-0.88) in the validation set. In addition, it achieved a sensitivity of 81.63% (95% CI: 69.39-91.84) and 68.00% (95% CI: 48.00--4.00), a specificity of 77.42% (95% CI: 72.18-82.66) and 72.51% (95% CI: 65.50-78.96), an accuracy of 78.1% (95% CI: 73.4-82.4) and 71.9% (95% CI: 65.3-78.6), a positive predictive value (PPV) of 41. 67% (95% CI: 35.65-48.84) and 26.79% (95% CI: 19.40-34.33), respectively, and a negative predictive value (NPV) of 95.61% (95% CI: 92.86-97.99) and 94.07% (95% CI: 90.44-97.08) in the training and validation sets, respectively. Conclusion: The model can accurately rule out FTC in low-risk nodules, thereby providing surgeons with a practical tool to determine the necessary extent of surgical intervention for nodules flagged as suspicious by IOFS.

Establishing of 3D-FISH on frozen section and its applying in chromosome territories analysis in Populus trichocarpa.

KEY MESSAGE: Fluorescence in situ hybridization with frozen sections of root tips showed difference of chromosome territories distribution between autosome and sex-chromosome homologous pairs in Populus trichocarpa. The spatial organization of chromatin within the interphase nucleus and the interactions between chromosome territories (CTs) are essential for various biologic processes. Three-dimensional fluorescence in situ hybridization (3D-FISH) is a powerful tool for analyzing CTs, but its application in plants is limited. In this study, we established a 3D-FISH technique using frozen sections of Populus trichocarpa root tips, which was an improvement over the use of paraffin sections and enabled us to acquire good FISH signals. Using chromosome-specific oligo probes, we were able to analyze CTs in interphase nuclei in three dimensions. The distribution of chromosome pairs 17 and 19 in the 3D-preserved nuclei of P. trichocarpa root tip cells were analyzed and showed that the autosome pair 17 associated more often than sex chromosome 19. This research lays a foundation for further study of the spatial position of chromosomes in the nucleus and the relationship between gene expression and spatial localization of chromosomes in poplar.

Outcomes of Intraoperative Frozen Section Examination of Surgical Resection Margins of the Penis in Penile Cancer.

INTRODUCTION: Frozen section examination (FSE) of the tumor resection margins is important during penile-preserving surgery (PPS) in penile cancer. The margin status will impact on how much penile or urethral tissue is excised. We aim to evaluate the outcomes of intraoperative FSE of resection margins in PPS. PATIENTS AND METHODS: A retrospective analysis of patients with penile squamous cell carcinoma (SCC) who underwent a FSE of resection margins between 2010 and 2022 was conducted. FSEs were compared with the final histopathological analysis and the Diagnostic Testing Accuracy (DTA): sensitivity, specificity, positive (PPV) and negative predictive values (NPV) were calculated. RESULTS: Overall, 137 FSE were performed. The median (IQR) age was 65 (53-75) years. 118 (86.1%) patients had negative FSE margins, 16 (11.7%) had positive FSE margins and 3 (2.2%) had equivocal (atypical cells) results. The sensitivity, specificity, PPV, NPV and diagnostic accuracy of penile FSE were 66.7%, 100%, 100%, 93.2% and 94% respectively. 18 patients underwent further resection in the same episode due to a positive or equivocal FSE and 12 (66.7%) achieved negative margins. Limitations include the retrospective nature of the study and lack of control arm to compare with. CONCLUSIONS: Intraoperative FSE performed at our center for the assessment of penile SCC margins is 66.7% sensitive and 100% specific. FSE should be considered in PPS, as it's an essential and a reliable diagnostic tool in minimizing over-treatment.

Pathology diagnosis of intraoperative frozen thyroid lesions assisted by deep learning.

BACKGROUND: Thyroid cancer is a common thyroid malignancy. The majority of thyroid lesion needs intraoperative frozen pathology diagnosis, which provides important information for precision operation. As digital whole slide images (WSIs) develop, deep learning methods for histopathological classification of the thyroid gland (paraffin sections) have achieved outstanding results. Our current study is to clarify whether deep learning assists pathology diagnosis for intraoperative frozen thyroid lesions or not. METHODS: We propose an artificial intelligence-assisted diagnostic system for frozen thyroid lesions that applies prior knowledge in tandem with a dichotomous judgment of whether the lesion is cancerous or not and a quadratic judgment of the type of cancerous lesion to categorize the frozen thyroid lesions into five categories: papillary thyroid carcinoma, medullary thyroid carcinoma, anaplastic thyroid carcinoma, follicular thyroid tumor, and non-cancerous lesion. We obtained 4409 frozen digital pathology sections (WSI) of thyroid from the First Affiliated Hospital of Sun Yat-sen University (SYSUFH) to train and test the model, and the performance was validated by a six-fold cross validation, 101 papillary microcarcinoma sections of thyroid were used to validate the system's sensitivity, and 1388 WSIs of thyroid were used for the evaluation of the external dataset. The deep learning models were compared in terms of several metrics such as accuracy, F1 score, recall, precision and AUC (Area Under Curve). RESULTS: We developed the first deep learning-based frozen thyroid diagnostic classifier for histopathological WSI classification of papillary carcinoma, medullary carcinoma, follicular tumor, anaplastic carcinoma, and non-carcinoma lesion. On test slides, the system had an accuracy of 0.9459, a precision of 0.9475, and an AUC of 0.9955. In the papillary carcinoma test slides, the system was able to accurately predict even lesions as small as 2 mm in diameter. Tested with the acceleration component, the cut processing can be performed in 346.12 s and the visual inference prediction results can be obtained in 98.61 s, thus meeting the time requirements for intraoperative diagnosis. Our study employs a deep learning approach for high-precision classification of intraoperative frozen thyroid lesion distribution in the clinical setting, which has potential clinical implications for assisting pathologists and precision surgery of thyroid lesions.

Sensitivity of frozen section analysis in patients with ovarian adult granulosa cell tumor, a multi-center study.

INTRODUCTION: We aimed to demonstrate the sensitivity of frozen section for patients with adult granulosa cell tumor (AGCT) and analyze the clinico-pathological factors that may be associated with sensitivity. MATERIAL METHODS: This is a multicenter study including data of 10 Gynecological Oncology Departments. Frozen-section results of patients who had ovarian AGCT at the final pathology report were retrospectively analyzed. The relation between clinico-pathological characteristics such as age, tumor size, Ca-125 level, presence of ascites, omental metastasis, menopausal status and peritoneal cytology, and the sensitivity of frozen section in patients with AGCT were evaluated. The sensitivity of frozen section diagnosis was determined by comparing the frozen section result with the final pathological diagnosis. RESULTS: Frozen section results of 274 patients with AGCT were obtained. The median age of the patients was 52 years (range, 17-82 years). Totally, 144 (52.7%, n = 273) patients were postmenopausal. The median tumour size was 90 mm (range, 9-700 mm). The median preoperative Ca-125 level was 23 IU/mL (range, 2-995 IU/mL). The sensitivity of frozen section for detecting AGCT was 76.3%. Any association between the sensitivity of frozen section and menopausal status, presence of ascites, positive cytology, omental metastasis, tumor size, Ca-125 level, age could not be shown. CONCLUSION: It is important to know the diagnosis of AGCT intraoperatively, and we demonstrated the sensitivity of frozen-section for these tumors as 76.3%.

Intraoperative margin assessment during radical prostatectomy: is microscopy frozen in time or ready for digital defrost?

Intraoperative frozen section (IFS) is used with the intention to improve functional and oncological outcomes for patients undergoing radical prostatectomy (RP). High resource requirements of IFS techniques such as NeuroSAFE may preclude widespread adoption, even if there are benefits to patients. Recent advances in fresh-tissue microscopic digital imaging technologies may offer an attractive alternative, and there is a growing body of evidence regarding these technologies. In this narrative review, we discuss some of the familiar limitations of IFS and compare these to the attractive counterpoints of modern digital imaging technologies such as the speed and ease of image generation, the locality of equipment within (or near) the operating room, the ability to maintain tissue integrity, and digital transfer of images. Confocal laser microscopy (CLM) is the modality most frequently reported in the literature for margin assessment during RP. We discuss several imitations and obstacles to widespread dissemination of digital imaging technologies. Among these, we consider how the 'en-face' margin perspective will challenge urologists and pathologists to understand afresh the meaning of positive margin significance. As a part of this, discussions on how to describe, categorize, react to, and evaluate these technologies are needed to improve patient outcomes. Limitations of this review include its narrative structure and that the evidence base in this field is relatively immature but developing at pace.

Centralized prostatectomy with intraoperative NeuroSAFE margin assessment improves surgical margin control.

AIMS: To investigate the surgical margin status in patients with prostate cancer who underwent robot-assisted radical prostatectomy (RARP) with intraoperative neurovascular structure-adjacent frozen-section analysis (NeuroSAFE) and evaluate differences compared to patients who underwent radical prostatectomy without NeuroSAFE. PATIENTS AND METHODS: Between September 2018 and January 2021, 962 patients underwent centralized RARP with NeuroSAFE. A secondary resection was performed in case of a positive surgical margin (PSM) on intraoperative frozen section (IFS) analysis to convert a PSM into a negative surgical margin (NSM). A retrospective cohort consisted of 835 patients who had undergone radical prostatectomy in a tertiary centre without NeuroSAFE between January 2000 and December 2017. We performed multivariable logistic regression to evaluate differences in risk of PSM between cohorts after controlling for clinicopathological variables. RESULTS: Patients operated with NeuroSAFE in the centralized clinic had 29% PSM at a definitive pathological RP examination. The median cumulative length of definitive PSM was 1.1 mm (interquartile range: 0.4-3.8). Among 275 men with PSM, 136 (49%) had a cumulative length ≤1 mm and 198 (72%) ≤3 mm. After controlling for PSA, Grade group, cribriform pattern, pT-stage, and pN-stage, patients treated in the centralized clinic with NeuroSAFE had significantly lower odds on PSM (odds ratio [OR]: 0.70, 95% confidence interval [CI]: 0.56-0.88; P = 0.002), PSM length >1 mm (OR: 0.14, 95% CI: 0.09-0.22; P < 0.001), and >3 mm (OR: 0.21, 95% CI: 0.14-0.30; P < 0.001). CONCLUSION: This study provides a detailed overview of surgical margin status in a centralized RP NeuroSAFE cohort. Centralization with NeuroSAFE was associated with lower PSM rates and significantly shorter PSM cumulative lengths, indicating improved control of surgical margin status.

[Common issues and solutions in intraoperative frozen pathological diagnosis of small pulmonary nodules].

With the development of chest CT screening, surgically resected lung tumors have shifted from predominantly large masses to predominantly small nodules. The intraoperative frozen diagnosis of pulmonary small nodules faces many challenges, such as the accurate understanding about the concepts of adenocarcinoma in situ, minimally invasive adenocarcinoma and lepidic adenocarcinoma, as well as their differential diagnosis with small size invasive adenocarcinoma, benign tumors (such as bronchiolar adenoma, sclerosing pneumocytoma, etc.), metastatic tumors and so on. This study summarizes some common problems encountered in the intraoperative frozen diagnosis of small pulmonary nodules in daily practice, focusing on the diagnosis and differential diagnosis of adenocarcinoma, in order to make the accurate intraoperative frozen diagnosis of small pulmonary nodules and diminish misdiagnosis.

Agreement between frozen section and histopathology to detect malignancy in adnexal masses according to size and morphology by ultrasound.

Objective: Management of suspect adnexal masses involves surgery to define the best treatment. Diagnostic choices include a two-stage procedure for histopathology examination (HPE) or intraoperative histological analysis - intraoperative frozen section (IFS) and formalin-fixed and paraffin-soaked tissues (FFPE). Preoperative assessment with ultrasound may also be useful to predict malignancy. We aimed at determining the accuracy of IFS to evaluate adnexal masses stratified by size and morphology having HPE as the diagnostic gold standard. Methods: A retrospective chart review of 302 patients undergoing IFS of adnexal masses at Hospital de Clínicas de Porto Alegre, between January2005 and September2011 was performed. Data were collected regarding sonographic size (≤10cm or >10cm), characteristics of the lesion, and diagnosis established in IFS and HPE. Eight groups were studied: unilocular lesions; septated/cystic lesions; heterogeneous (solid/cystic) lesions; and solid lesions, divided in two main groups according to the size of lesion, ≤10cm or >10cm. Kappa agreement between IFS and HPE was calculated for each group. Results: Overall agreement between IFS and HPE was 96.1% for benign tumors, 96.1% for malignant tumors, and 73.3% for borderline tumors. Considering the combination of tumor size and morphology, 100% agreement between IFS and HPE was recorded for unilocular and septated tumors ≤10cm and for solid tumors. Conclusion: Stratification of adnexal masses according to size and morphology is a good method for preoperative assessment. We should wait for final HPE for staging decision, regardless of IFS results, in heterogeneous adnexal tumors of any size, solid tumors ≤10cm, and all non-solid tumors >10cm.

Intraoperative Pathology Consultation in Patients With p16-Positive Unknown Primary Squamous Cell Carcinoma.

Importance: Current guidelines recommend intraoperative frozen section(s) during diagnostic surgery for squamous cell carcinoma for unknown primary tumors (SCCUP). Objective: To determine the utility of intraoperative pathology consultation during transoral robotic surgery (TORS) in localizing primary tumors and influencing need for adjuvant therapy. Design, Setting, and Participants: A retrospective case series including 47 adult patients with human papillomavirus (HPV)-associated SCCUP who underwent TORS/oropharyngectomy between January 2016 and February 2023 was carried out at a single tertiary care hospital. The analysis took place on May 13, 2024. Exposures: Nodal stage, tonsillectomy history, extranodal extension (ENE). Main Outcomes and Measures: Intraoperative pathology consultation and final pathology results were compared with surgical outcomes, including margin revision, need for second procedure and/or radiation with or without chemotherapy. Results: This study included 47 adult patients. Mean (range) age was 61 (41-79) years; patients were mostly men (37 [79%]). Overall, primary tumors were identified in 37 patients (79%), including all cases with positive nodes involving more than 1 neck level. Patients whose primary tumor was not found tended to have tobacco use history (8/10 vs 13/37 [35%]; difference, 45%; 95% CI, 16%-74%) and absence of ENE (8/10 vs 15/37 [41%]; difference, 39%; 95% CI, 10%-68%). Primary tumor was identified intraoperatively in 18 of 37 patients (49%). SCCs identified intraoperatively were significantly larger than SCCs found on permanent sections only: mean (SE), 1.2 (0.13) cm vs 0.5 (0.1) cm (difference, 0.7 cm; 95% CI, 0.53-1.94). The sensitivity, specificity, positive predictive value, and negative predictive value of intraoperative consultation was 49% (95% CI, 33%-64%), 100% (95% CI, 100%-100%), 100%, and 34% (95% CI, 19%-53%), respectively. Margins were revised in 11 of 18 patients (61%) whose primary tumor was identified intraoperatively (during original procedure) and in 3 of 19 patients (16%) whose primary tumor was identified on permanent pathologic findings only (during a second procedure) (11/18 [61%] vs 3/19 [16%]; difference, 45%; 95% CI, 17%-73%). However, there was no significant difference in the use of adjuvant radiotherapy with or without chemotherapy or need for a second procedure based on intraoperative primary tumor localization. Conclusion and Relevance: In this case series study, the sensitivity and negative predictive value of intraoperative pathology consultation among 47 patients was less than 50%. Given the lack of influence on the need for radiotherapy with or without chemotherapy or second procedure, the practical utility of routine intraoperative frozen section requires further scrutiny.

Intraoperative frozen section evaluation of ovarian sex cord-stromal tumours and their mimics: a study of 121 cases with emphasis on potential diagnostic pitfalls.

Ovarian sex cord-stromal tumours (SCSTs) present diagnostic difficulties during frozen section (FS) consultations due to their diverse morphology. This study aimed to evaluate the accuracy of FS evaluation of SCSTs in our institution, as well as to examine the reasons leading to incorrect FS diagnosis. Cases mimicking SCSTs and diagnosed as such during FS were also highlighted. We analysed 121 ovarian SCST cases and their mimics which underwent FS consultations over a 10-year period, to evaluate FS accuracy, reasons for deferrals and discrepancies. FS diagnoses were concordant, deferred and discrepant compared to the final diagnosis in 50 (41.3%), 39 (32.2%) and 32 (26.5%) cases, respectively. Major discrepancies (9/121, 7.4%) were mostly related to the diagnosis of adult granulosa cell tumour (AGCT). A fibromatous AGCT was misinterpreted as fibroma on FS, while a cystic AGCT was called a benign cyst. Conversely, a mesonephric-like adenocarcinoma, a sertoliform endometrioid carcinoma and a thecoma were misinterpreted as AGCT on FS. Another discrepant case was a Krukenberg tumour with prominent fibromatous stroma in which malignant signet ring cells were overlooked and misinterpreted as fibroma. Minor discrepancies were primarily associated with fibroma (21/23, 91.3%), wherein minor but potentially impactful details such as cellular fibroma and mitotically active cellular fibroma were missed due to sampling issues and misinterpretation as leiomyoma. FS evaluation for ovarian SCSTs demonstrated an overall accuracy of 78.5%, 81.0% and 81.8% for benign, uncertain/low malignant potential and malignant categories, respectively. There was no FS-related adverse clinical impact in all cases with available follow-up information (120/121 cases). Intraoperative FS evaluation of ovarian SCSTs is challenging. A small number of cases were misinterpreted, with AGCTs being the primary group where errors occur. Awareness of common diagnostic pitfalls and difficulties, alongside application of a stepwise approach, including (1) obtaining comprehensive clinical information, (2) thorough macroscopic examination and directed sampling, (3) meticulous microscopic examination with consideration of pitfalls and mimics, (4) effective communication with surgeons in difficult cases, and (5) consultation of subspecialty colleagues in challenging cases, will enhance pathologists' reporting accuracy and management of such cases in the future.

Intraoperative diagnosis of breast cancer metastasis in axillary lymph nodes: Cytological Smear vs. Frozen Section.

BACKGROUND: Intraoperative evaluation of axillary lymph nodes is sometimes required to determine the extent of surgery. In this study, we wished to assess the reliability of cytologic smear (CS) in determining lymph node involvement with tumor. Theoretically, CS provides more substance for examination than touch-imprint cytology and is faster to perform than frozen section (FS). We hypothesized that CS sensitivity for tumor cell detection in the lymph nodes would be similar to FS, at least 0.90. METHODS: This was a retrospective observational study at the Rambam Health Care Campus (January, 2013-June, 2020). Lymph nodes underwent intraoperative evaluation using either CS or FS, based on the availability of a cytologist at the time of the examination. Both intraoperative evaluations were compared to the final pathology following fixation with formalin. RESULTS: Eighty-eight patients undergoing intraoperative analysis were analyzed (51 CS, 37 FS). False-negative tests were recorded in only 1 patient evaluated by each of the 2 methods. This resulted in sensitivity 0.91 (95%CI 0.59, 1.00) for CS and 0.88 (95%CI 0.47, 1.00) for FS, specificity 1.00 (95%CI 0.91, 1.00) for CS and 1.00 (95%CI 0.88, 1.00) for FS, positive predictive value 1.00 (95%CI 0.69, 1.00) for CS and 1.00 (95%CI 0.59, 1.00) for FS, and negative predictive value 0.98 (95%CI 0.87, 1.00) for CS and 0.97 (95%CI 0.83, 1.00) for FS. CONCLUSIONS: The sensitivity of the CS in this study is comparable to that of FS and due to shorter analysis time required is the preferred method at our institution.

The Prevalence of Sentinel Lymph Node Positivity and Implications for the Utility of Frozen Section Diagnosis Following Neoadjuvant Systemic Therapy in Patients with Clinically Node-Negative HER2-Positive or Triple-Negative Breast Cancer.

BACKGROUND: Axillary dissection is the standard of care for patients with positive sentinel lymph nodes (SLNs) following neoadjuvant systemic therapy. Frozen section can provide intraoperative information regarding the need for axillary dissection during the index operation. However, there are limited data on the utility of frozen section in patients with clinically node-negative (cN0) HER2-positive or triple-negative breast cancer. METHODS: We conducted a single-institution observational cohort study including patients with non-inflammatory, cN0, HER2-positive or triple-negative breast cancer treated with neoadjuvant systemic therapy between 2015 and 2019. We estimated the prevalence of SLN positivity and the diagnostic test characteristics of SLN frozen section. RESULTS: Overall, 662 patients were eligible for inclusion, and 44 patients had one or more positive SLNs (prevalence: 6.6%, 95% confidence interval [CI] 4.9-8.8). There were 490 (74.0%) patients who had intraoperative frozen section, and 19 (3.9%) tested positive among 33 (6.7%) with positive final pathology. Frozen section sensitivity was 57.6% (95% CI 39.2-74.5), specificity was 100% (95% CI 99.2-100), positive predictive value was 100% (95% CI 82.4-100), and negative predictive value was 97.0% (95% CI 95.1-98.4). The sensitivity of frozen section for detection of micrometastases or isolated tumor cells was 35.3% (95% CI 14.2-61.7). CONCLUSION: In patients with cN0 HER2-positive or triple-negative breast cancer who have been treated with neoadjuvant therapy, positive SLNs are uncommon and frozen section sensitivity is modest. Decisions to defer SLN evaluation to final pathology, which may be reasonable in many settings, can be informed, in part, by these findings.

Impact of frozen section on long-term outcomes in robot-assisted laparoscopic prostatectomy.

OBJECTIVES: To compare 1-year functional and 5-year oncological outcomes of men undergoing robot-assisted laparoscopic prostatectomy (RALP) with neurovascular structure-adjacent frozen-section examination (NeuroSAFE) with those in men undergoing RALP without NeuroSAFE (standard of care [SOC]). SUBJECTS AND METHODS: Men undergoing RALP in our centre between 1 January 2009 and 30 June 2018 were enrolled from a prospectively maintained database. Patients were excluded if they had undergone preoperative therapy or postoperative adjuvant therapy or were enrolled in clinical trials. Patients were grouped based on use of NeuroSAFE. Follow-up was censored at 5 years. The primary outcome was difference in time to biochemical recurrence (BCR) on multivariable analysis, defined as prostate-specific antigen (PSA) >0.2 ng/L on two consecutive measurements. Secondary outcomes were difference in 1-year erectile dysfunction and incontinence. RESULTS: In the enrolment period, 1199 consecutive men underwent RALP, of whom 1140 were eligible, including 317 with NeuroSAFE and 823 with SOC. The median PSA follow-up was 60 months in both groups. Rates of 5-year BCR were similar on Kaplan-Meier survival curve analysis (11% vs 11%; P = 0.9), as was time to BCR on multivariable Cox proportional hazards modelling (hazard ratio 1.2; P = 0.6). Compared with the SOC group at 1 year, the NeuroSAFE group had similar unadjusted rates of incontinence (5.1% vs 7.7%) and lower unadjusted impotence (57% vs 80%). On multivariable analysis, NeuroSAFE patients had equivalent risk of incontinence (odds ratio [OR] 0.59, 95% CI 0.17-1.6; P = 0.4) but significantly reduced risk of erectile dysfunction (OR 0.37, 95% CI 0.22-0.60; P < 0.001). CONCLUSIONS: For men undergoing RALP, compared with SOC, NeuroSAFE patients had equivalent time to BCR and risk of 1-year incontinence, and significantly lower risk of 1-year erectile dysfunction.

Predictive factors of frozen section in transoral microlaryngeal surgery for suspicious glottic lesions.

OBJECTIVE: Frozen biopsy may guide surgical intraoperative decisions. We evaluated the accuracy of frozen biopsy for diagnosing benign, dysplastic and malignant laryngeal lesions, compared to paraffin section (gold standard). METHODS: Retrospective review of the charts of all patients presenting with laryngeal lesions suspicious of malignancy, who underwent laryngeal microsurgery with frozen biopsy in our institution, between 2015 and 2020. Results of frozen biopsy and paraffin section examinations were compared. RESULTS: Among 113 samples of 89 patients, paraffin section diagnosed 23 benign, 31 dysplastic and 59 malignant lesions. The accuracy of the frozen biopsy in identifying dysplasia or malignancy was 80.5% (91/113), and greater for lesions >5 mm (78.8% × 51.5%; p = 0.009). The positive and negative predictive values, sensitivity and specificity were 95.9%, 51.3%, 78.9% and 86.9%, respectively. CONCLUSIONS: Frozen section is a reliable tool when malignancy is detected, but almost half of benign results exhibit dysplasia or malignancy in paraffin section. Other clinical parameters should be considered in intraoperative decisions to prevent undertreatment.

Comparison of staining quality between rapid and routine hematoxylin and eosin staining of frozen breast tissue sections: an observational study.

OBJECTIVE: To compare the staining quality between rapid hematoxylin and eosin (H&E) staining and routine H&E staining of frozen breast tissue sections. METHODS: In this cross-sectional observational study, 120 frozen breast tissue sections were randomly assigned to rapid or routine H&E staining (n = 60 per group). Rapid H&E staining used a 7:1 mixture of modified Gill's hematoxylin and alcohol-soluble 1% eosin Y. The staining quality of each section was evaluated and scored. A score of >7 was considered excellent, a score of 6 to 7 good, and a score of ≤5 poor. RESULTS: The staining time for rapid staining was approximately 3 minutes, whereas that of routine staining was approximately 12 minutes. There were no significant differences in the staining quality scores or proportions of sections in each grade between the two staining methods. The proportions of sections that were classified as excellent or good were 96.7% and 98.3% for rapid and routine staining, respectively. CONCLUSIONS: In frozen breast tissue sections, rapid H&E staining may provide staining quality that is comparable to that of routine staining, while markedly reducing the staining time.

Immunofluorescence staining of chloroplast proteins with frozen sections of plant tissues.

KEY MESSAGE: Immunofluorescence staining with frozen sections of plant tissues and a nest tube is convenient and effective, and broadens the applicability of immunofluorescence staining. Immunofluorescence staining is an indispensable and extensively employed technique for determining the subcellular localization of chloroplast division proteins. At present, it is difficult to effectively observe the localization of target proteins in leaves that are hard, or very thin, or have epidermal hair or glands with the current immunofluorescence staining methods. Moreover, signals of target proteins were predominantly detected in mesophyll cells, not the cells of other types. Thus, the method of immunofluorescence staining was further explored for improvement in this study. The plant tissue was embedded with 50% PEG4000 at -60℃, which was then cut into sections by a cryomacrotome. The sections were immediately immersed in fixation solution. Then, the sample was transferred into a special nested plastic tube, which facilitated the fixation and immunofluorescence staining procedures. The use of frozen sections in this method enabled a short processing time and reduced material requirements. By optimizing the thickness of the sections, a large proportion of the cells could be well stained. With this method, we observed the localization of a chloroplast division protein FtsZ1 in the wild-type Arabidopsis and various chloroplast division mutants. Meanwhile, the localization of FtsZ1 was also observed not only in mesophyll cells, but also in guard cells and epidermal cells in a lot of other plant species, including many species with hard leaf tissues. This method is not only easy to use, but also expands the scope of applicability for immunofluorescence staining.