Achieving disease free distal ureteral margin at the time of radical cystectomy: Why and for whom? (an overview of literature)

OBJECTIVE

Achieving negative status of distal ureteral margin at the time of radical cystectomy (RC), and its therapeutic benefit, remains controversial. The aim of this review was to evaluate frequency, reliability and impact of positive distal ureteral margin after radical cystectomy for bladder cancer on upper tract recurrence, cancer specific and overall survival, and to identify best candidates for intraoperative frozen section analyses.

MATERIAL AND METHODS

A systemic review was performed following the PRISMA guideline. PubMed/Medline (with following terms; bladder cancer or cystectomy and frozen section or ureteral margin), and Cochrane Library were searched up to April 2020, to identify all papers evaluating distal ureteral margin and discussing clinical interest. Previous reviews and single case reports were excluded.

RESULTS

In total, thirty-two relevant studies were identified. Mean rate of positive ureteral frozen section after RC was close to 10% [1.1-25.4%]. Frozen section (FS) achieved a very good specificity [83-100%] and reserved sensibility [45-100%]. In many cases, an initial positive margin on FS can be converted to negative. Positive FS and/or PS (permanent section) were associated with upper urinary tract recurrence (UUTR). Conversion from positive FS to negative PS was associated with low UUTR frequency and better cancer survival in large retrospective studies. The relevant prognostic factor associated with positive FS and/or PS was CIS within the bladder.

CONCLUSION

FS should be recommended for patients with CIS within the bladder. Achieving negative FS/PS might be associated with lower rates of UUTR and better survival, for patients with higher life expectancy. Prospective randomized controlled studies need to be performed to provide definitive recommendations in this area.

Acute Invasive Fungal Sinusitis: A 30-Year Review of Pathology Practice and Possible Utility of the DiffQuik® Stain

Acute invasive fungal rhinosinusitis (AIFRS) is a fulminant disease with a high mortality rate. Here, we review the clinical and pathologic features of AIFRS over a 30-year period at a tertiary-care academic center focusing on diagnostic practice, especially the use of intra-operative consultation (IOC). A 1-year trial of intraoperative staining with DiffQuik® (DQ) was also assessed. There were 202 cases from 104 patients with AIFRS. The incidence of AIFRS increased over time (6.8 per year in the past decade versus 1.9 before 2009) as did the number of IOCs per case (2.4 per case in the past decade versus 0.6 before 2009). Disagreement between final diagnosis and IOC was seen in 8.3 % of patients, and the block-by-block error rate was 14.9 %. Fusarium was the most common fungus identified. An attempt to categorize the fungal organism based on histopathology was performed in 85.6 % of patients, with 91 % agreement with microbial cultures or PCR. Fungal hyphae were subjectively easier to identify on DQ stained cryostat sections compared to on routine hematoxylin and eosin stained sections and hyphae were identified in all 5 blocks in which organisms were present. The increasing incidence of AIFRS and expanding use of IOC indicate a need to improve and standardize the diagnostic protocol. The use of DQ as visual aid in IOC for AIFRS may be useful.

Patients with no recurrence of infection five years after two-stage revision hip arthroplasty may be classified as periprosthetic infection 'in remission'

AIMS

We aimed to report the mid- to long-term rates of septic and aseptic failure after two-stage revision surgery for periprosthetic joint infection (PJI) following total hip arthroplasty (THA).

METHODS

We retrospectively reviewed 96 cases which met the Musculoskeletal Infection Society criteria for PJI. The mean follow-up was 90 months (SD 32). Septic failure was assessed using a Delphi-based consensus definition. Any further surgery undertaken for aseptic mechanical causes was considered as aseptic failure. The cumulative incidence with competing risk analysis was used to predict the risk of septic failure. A regression model was used to evaluate factors associated with septic failure. The cumulative incidence of aseptic failure was also analyzed.

RESULTS

There were 23 septic failures at final follow-up, with a cumulative incidence of 14% (95% confidence interval (CI) 8% to 22%) at one year, 18% (95% CI 11% to 27%) at two years, 22% (95% CI 14% to 31%) at five years, and 23% (95% CI 15% to 33%) at ten years. Having at least one positive culture (hazard ratio (HR) 2.38 (interquartile range (IQR) 1.19 to 4.74); p = 0.013), or a positive intraoperative frozen section (HR 2.55 (IQR 1.06 to 6.15); p = 0.037) was significantly associated with septic failure after reimplantation. With dislocation being the most common cause of aseptic revision (5.2%), the cumulative incidence of aseptic failure was 1% (95% CI 0% to 5%) at one year, 6% (95% CI 1% to 8%) at five years, and 8% (95%CI 3% to 17%) at ten years.

CONCLUSION

If there is no recurrent infection in the five years following reimplantation, the chances of further infection thereafter are remote. While the results of a frozen section may be a reliable guide to the timing of reimplantation, intraoperative culture has, currently, only prognostic value. Surgeons should be aware that instability remains a potential indication for further revision surgery. Cite this article: Bone Joint J 2021;103-B(1):79-86.

Effects of brain tissue section processing and storage time on gene expression

The pre-processing of samples is important factors that affect the results of the RNA-sequencing (RNA-seq) data. However, the effects of frozen sections storage conditions on the integrity of RNA and sequencing results haven't been reported. The study of frozen section protection schemes can provide reliable experimental results for single-cell and spatial transcriptome sequencing. In this study, RNA was isolated to be studied for RNA from brain section at different temperatures (RT: room temperature, -20 °C) and storage time (0 h, 2 h, 4 h, 8 h, 12 h, 16 h, 24 h, 7day, 3week, 6month). The stability of reference genes was validated using reverse transcription quantitative real-time polymerase chain reaction (qRT-PCR). The results showed that the storage at room temperature significantly affected RNA integrity number (RIN), and the RIN value was lower with the prolongation of storage, while the storage at -20 °C exerted less effect on the RIN value. Cresyl violet staining for brain tissue sections had little effect on RNA integrity. 1925, 899 and 3390 differential expression genes (DEGs) were screened at 2 h, 4 h and 8 h at room temperature, respectively. A total of 892, 478 and 619 genes were shown to be differentially expressed at -20 °C for 7d, 3w and 6 m, respectively. Among them, the expression of glycoprotein m6a (Gpm6a), calmodulin 1 (Calm1), calmodulin 1 (Calm2), thymosin, beta 4, X chromosome (Tmsb4x), ribosomal protein S21 (Rps21) and so on were correlated with RNA quality. According to the expression stability of 4 reference genes (Actb: beta-actin; Gapdh: glyceraldehyde-3-phosphate dehydrogenase; 18S: 18S ribosomal; Hprt1: hypoxanthine phosphoribosyltransferase 1), 18S is the most stable reference gene in the brain. In conclusion, the storage temperature and time of frozen sections have significant effects on RNA integrity and sequencing results. But there are still some genes that are stable and not affected by worsening of overall RNA integrity ie the decrease of RIN value. In addition, 1% cresyl violet staining can protect RNA.

Improved survival after pancreatic re-resection of positive neck margin in pancreatic cancer patients. A systematic review and network meta-analysis

The oncological benefit of achieving a negative pancreatic neck margin through re-resection after a positive frozen section (FS) is debated. Aim of this network meta-analysis is to evaluate the survival benefit of re-resection after intraoperative FS neck margin examination following pancreatectomy for ductal adenocarcinoma. A systematic search of studies comparing different strategies for the management of positive FS was performed. Patients were classified in three groups based on FS and permanent section (PS): Group A (FS-, PS-R0), Group B (FS+, PS-R0), Group C (FS±, PS-R1). A frequent random-effects network-meta-analysis was made reporting the surface under the cumulative ranking (SUCRA). Primary endpoint was overall survival (OS). Secondary endpoints were pathological outcomes. Seven retrospectives studies with 4205 patients were included and 99.1% of the pancreatic resections were pancreatoduodenectomies. Group A had the highest probability of better OS (SUCRA = 90%), compared to Group B (SUCRA = 48.7%) and Group C, which was the worst prognostic scenario (SUCRA = 11.3%). Group B had still a probability of longer OS compared to Group C (SUCRA = 48.7% vs 11.3%). Pathological features were more favourable in Group A, with the highest SUCRA for T1-T2 tumors (92.6%), N0 status (89.4%), absence of perineural invasion (92.3%). Heterogeneity was low (τ-value <0.1) for OS, and moderate (τ-values: 0.1-0.6) for pT, pN, and perineural invasion. In conclusion, negative neck margin after primary resection (FS negative) or re-resection of a positive FS was associated with improved survival compared with PS-R1. However, any intraoperative positive FS can be considered as a prognostic factor associated with a more aggressive disease.

Matrix-Assisted Laser Desorption/Ionization-Mass Spectrometry Imaging of Lipids in the Ischemic Rat Brain Section: A Practical Approach

Matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) of lipids is considered one of the shotgun lipidomic techniques that explores the in situ distribution of lipids in tissue sections. To successfully perform this task, knowledge and experience in the conventional cryosection, tissue section collection and handling, and mass spectrometry data analysis and signal processing are needed. A MALDI-MSI protocol covering from the fresh organ collection, cryosection and tissue processing, matrix application, MSI data acquisition, to the final MSI display of lipid distribution in the brain section of an ischemic stroke rat is described to exemplify this technique. Due to the multidisciplinary nature of this approach, plenty of preparation, practice, and familiarization to several critical steps ahead of the engagement with actual biological samples are needed to ensure a successful MALDI-MSI presentation of lipids in situ.

Accuracy and Reproducibility of Intraoperative Assessment on Tumor Spread Through Air Spaces in Stage 1 Lung Adenocarcinomas

INTRODUCTION

Tumor spread through air spaces (STAS) is associated with worse prognosis in early-stage lung adenocarcinomas, particularly in sublobar resection. Intraoperative consultation for STAS has been advocated to guide surgical management. However, data on accuracy and reproducibility of intraoperative assessment of STAS remain limited. We evaluated diagnostic yield, interobserver agreement (IOA), and intraobserver agreement (ITA) for STAS detection on frozen section (FS).

METHODS

A panel of three pathologists evaluated stage 1 lung adenocarcinomas (n = 100) for the presence or absence of STAS and artifacts as reference. Five pulmonary pathologists independently reviewed all cases in two rounds, detecting STAS and artifacts in FS and the corresponding FS permanent and non-FS permanent, with a consensus conference between rounds.

RESULTS

The FS had low sensitivity (44%), high specificity (91%), relatively high accuracy (71%), and overall area under the receiver operating characteristic curve of 0.67 for detecting STAS. The average ITA was moderate for both STAS (κ_mean: 0.598) and artifact (κ_mean: 0.402) detection on FS. IOA was moderate for STAS (κ_round-1: 0.453; κ_round-2: 0.506) and fair for artifact (κ_round-1: 0.300; κ_round-2: 0.204) detection on FS. IOA for STAS improved in FS permanent and non-FS permanent, whereas ITA was similar across section types. On multivariable logistic regression, the only significant predictor of diagnostic discordance was the presence of artifacts.

CONCLUSIONS

FS is highly specific but not sensitive for STAS detection in stage 1 lung adenocarcinomas. IOA on STAS is moderate in FS and improved only marginally after a consensus conference, raising concerns regarding global implementation of intraoperative assessment of STAS and warranting more precise criteria for STAS and artifacts.

Does diagnostic accuracy of surgeon's perception outweigh frozen section analysis in determining intraoperative clear mucosal surgical margins in oral squamous cell carcinoma patients?

Introduction:

The lucrativeness of the frozen section for intraoperative margin assessment in head and neck squamous cell carcinoma is debatable till date. The purpose of this study was to evaluate whether surgeon's perception by gross examination (GE) of margin is an alternative to frozen section.

Aim:

The aim was to compare the diagnostic accuracy (DA) of surgeon's perception of tumor-free mucosal and soft-tissue surgical margins intraoperatively assessed by GE and frozen section analysis (FSA).

Methodology:

A prospective, observational study was conducted on 59 histologically proven cases of oral squamous cell carcinoma. Two hundred and thirty-six mucosal margins were assessed by an experienced surgeon (ES) and thereafter subjected subsequently to FSA. These results were compared with the gold standard histopathology (HPE). The sensitivity (SS), specificity (SP), positive predictor value (PPV), negative predictor value (NPV), and DA of surgeon's perception by GE were calculated and subsequently compared with FSA and HPE using descriptive and inferential statistics.

Results:

The SS, SP, PPV, NPV, and DA of ES by GE were 80%, 99.12%, 80%, 99.12%, and 98.30%, respectively when compared to HPE, and the SS of 90%, SP of 98.32%, PPV, NPV, and DA were 69.23%, 99.57%, and 97.98%, respectively when compared with HPE. The results of the surgeon's perception by GE were comparable to the results of FSA.

Conclusion:

The study concludes that surgeon's perception by GE is upfront reliable alternative intraoperative method to FSA in places where FS is not available.

Frozen section in thyroid gland follicular neoplasms: It's high time to abandon it!

Thyroid nodules are a very common clinical condition. The 2015 American Thyroid Association (ATA) guidelines recommend surgical excision for Bethesda IV nodules. The use of intraoperative frozen section (FS) has been recommended as a strategy to tailor the extent of the initial surgery. We critically evaluated the literature that discusses the utility and cost-effectiveness of FS to make an intraoperative decision in patients with thyroid nodules classified as follicular neoplasm. FS should not be recommended as a routine intraoperative test to assess for malignancy in thyroid follicular patterned lesions due to its low performance; the high number of deferred results; the inability to adequately assess histologically defining features; the improvements in risk stratification guiding total thyroidectomy; and the low cost-effectiveness of FS.

Factors associated with discrepancy between fresh frozen and permanent biopsy from medical thoracoscopy: single center analysis of 172 medical flexible thoracoscopy cases

Background

Frozen sections prepared during medical thoracoscopy (MT) have precise diagnostic ability in pleural pathology and may assist in decision-making before pleurodesis. The present study evaluated the diagnostic sensitivity of frozen sections from flex-rigid MT, and further evaluated clinical parameters for their association with a discrepancy between frozen sections and permanent paraffin sections.

Methods

This retrospective study evaluated 172 patients who underwent flex-rigid MT between February 2017 and November 2019 at Incheon Saint Mary's Hospital.

Results

Of the 172 patients, 85 were pathologically diagnosed with malignancy based on permanent paraffin sections. An accurate diagnosis by fresh frozen section was feasible in 88.2% of the cases compared to the permanent paraffin sections. Among the 85 patients, 75 had malignancies in frozen sections, while 10 patients showed otherwise. In the 85 malignant cases, age, sex, the volume of effusion, thoracoscopic findings, as well as the final pathological diagnosis (lung vs. non-lung origin) were included in univariate analysis for an association with non-malignant frozen section results. High adhesion grade and malignancy other than lung cancer were significant factors associated with frozen section negative cases in a multivariable analysis.

Conclusions

Taking fresh frozen sections during MT using a flex-rigid bronchoscope is a useful diagnostic modality with reliable sensitivity for malignancy. However, if the pre-procedural diagnosis is likely to be a malignancy other than lung cancer, and if severe adhesions are present in the pleural cavity, the final pathological confirmation should be determined based on permanent paraffin sections, not only on fresh frozen sections.

Improved detection of sentinel lymph node metastases allows reliable intraoperative identification of patients with extended axillary lymph node involvement in early breast cancer

An improved procedure that allows accurate detection of negative sentinel lymph node (SLN) and of SLN macrometastases during surgery would be highly desirable in order to protect patients from further surgery and to avoid unnecessary costs. We evaluated the accuracy of an intraoperative procedure that combines touch imprint cytology (TIC) and subsequent frozen section (FS) analysis. 2276 SLNs from 1072 patients with clinical node-negative early breast cancer were evaluated during surgery using TIC. Only cytologically-positive SLN were subsequently analysed with a single FS, preserving cytologically-negative SLN for the final postoperative histological diagnosis. Sensitivity, specificity and the accuracy of this approach were analysed by comparing the results from intra- and postoperative SLN and axillary node evaluation. This intraoperative method displayed 100% specificity for SLN metastases and was significantly more sensitive for prognostically relevant macrometastases (85%) than for micrometastases (10%). Sensitivity was highest for patients with two or more positive LNs (96%) than for those with only one (72%). 98% of the patients with final pN2a-pN3a were already identified during surgery. Patients who received primary axillary lymph node dissection had significantly more frequent metastases in further LNs (44.6%). Sensitivity was highest for patients with luminal-B, HER2+ and triple negative breast cancer and for any subtype if Ki-67 > 40%. TIC and subsequent FS of cytologically-positive SLNs is highly reliable for detection of SLN macrometastases, and allows accurate identification of patients with a high risk of extended axillary involvement during surgery, as well as accurate histological diagnosis of negative SLN.

Toluidine blue versus frozen section for assessment of mucosal tumor margins in oral squamous cell carcinoma

BACKGROUND

When the resected specimen is sent for intraoperative margin assessment, all margins are grossly checked, and selected margins undergo a frozen section (FS) examination. Therefore, there is a possibility of sampling error. This study evaluated the effectiveness of using toluidine blue (TB) as an intraoperative triage screening tool to detect positive mucosal margins of the resected specimens of oral squamous cell carcinoma (OSCC) and serve as a guide for FS sampling.

METHODS

Surgical samples of 30 consecutive patients with biopsy-proven OSCC were included in the study. A total of 140 mucosal margins were analyzed intraoperatively by TB and FS, the results were compared with the final histopathology.

RESULTS

Of the 140 examined mucosal tumor margins, 14 stained positives with TB, six were true-positives, eight were false-positives, and there were no false-negatives, as confirmed by final histopathology of the same margins. The diagnostic performance measures were sensitivity 100.0%; specificity 94.0%; positive predictive value (PPV) 42.9%; negative predictive value (NPV) 100.0%; and accuracy 94.3% (95% CI: 89.0-97.5%). For FS, there were three true-positives, three false-negatives, and no false-positives. The diagnostic performance measures were sensitivity 50.0%; specificity 100.0%; PPV 100.0%; NPV 97.8%; and accuracy 97.9% (95% CI: 93.9-99.6%).

CONCLUSION

TB is less specific but more sensitive than FS for detecting positive mucosal margins of resected OSCC. Screening the tumor mucosal margins with TB before FS sampling may help identify more tumor-bearing margins.

TRIAL REGISTRATION

This trial was registered at ClinicalTrials.gov. Registration number: NCT03554967 . Registration date: June 13, 2018.

[Extent of resection in intrathyroidal medullary thyroid cancer]

Improvements in preoperative diagnostic modalities in conjunction with highly sensitive calcitonin assays, ultrasound and functional imaging modalities and differentiated genetic testing for detection of hereditary forms, have enabled detection and resection of medullary thyroid carcinoma at an increasingly earlier stage. These developments open up possibilities to deescalate primary surgery adapted to these stages and avoid surgical overtreatment in locally limited tumor growth: thus, promoting a shift from routinely recommended total thyroidectomy with bilateral central lymph node dissection in favor of limited unilateral thyroid resection. Prerequisites for limited thyroid resection include clinical evidence that the tumor is sporadic, unifocal and confined to the thyroid. Corresponding calcitonin levels should also indicate that a biochemical cure will be achieved after unilateral resection. A decisive structural prerequisite for such a limited concept is the low threshold availability of intraoperative frozen section analysis that reliably detects and evaluates a medullary thyroid carcinoma and can assess a breach of the thyroid capsule and desmoplasia with certainty.

Impact of histological components on selecting limited lymphadenectomy for lung adenocarcinoma ≤ 2 cm

OBJECTIVES

There is still some dispute regarding the performance of limited mediastinal lymphadenectomy (LML) even for lung adenocarcinoma ≤ 2 cm. We aimed to recognize the potential candidates who can benefit from LML based on the percentage of histological components (PHC).

METHODS

We analyzed 1160 surgical patients with invasive lung adenocarcinoma ≤ 2 cm from seven institutions between January 2012 and December 2015. All histological subtypes were listed in 5% increments by pathological slices. To test the accuracy of frozen section in judging PHC, frozen section slides from 140 cases were reviewed by three pathologists.

RESULTS

There were 882 patients with systematic mediastinal lymphadenectomy (SML) and 278 with LML. Multivariable analysis indicated that, the total percentage of micropapillary and solid components (PHC_MIP+S) > 5 % was the independent predictor of N2 metastasis (P < 0.001). Overall, recurrence-free survival (RFS) and overall survival (OS) favored SML compared with LML, but the subgroup analysis revealed LML and SML had similar prognosis in the group of PHC_MIP+S ≤ 5 %. Moreover, multivariable Cox analysis showed LML (vs. SML) was independently associated with worse prognosis for patients with PHC_MIP+S > 5 % (RFS, HR = 2.143, P < 0.001; OS, HR=1.963, P < 0.001), but not for those with PHC_MIP+S ≤ 5 % (RFS, P = 0.398; OS, P = 0.298). The sensitivity and specificity of frozen section to intraoperatively identify PHC_MIP+S ≤ 5 % were 97.6 % and 84.2 %, respectively.

CONCLUSIONS

PHC_MIP+S showed the predictive value for N2 metastasis and procedure-specific outcome (LML vs. SML). It may serve as a feasible indicator for identifying proper candidates of LML by using intraoperative frozen section.

[Intraoperative rapid frozen section-when meaningful, when necessary?]

Intraoperative frozen sections can significantly improve the results of numerous visceral surgical operations. For this a close cooperation between surgery and pathology is a basic prerequisite. The main indications are the diagnostics of unclear intraoperative findings and the assessment of resection margins. Just as in any other procedure, there are also limiting factors to be considered in frozen section examinations.

Accuracy of preoperative endometrial biopsy and intraoperative frozen section in predicting the final pathological diagnosis of endometrial cancer

BACKGROUND

Histotype and grade of endometrial cancer (EC) are prognostic factors of nodal involvement and thus of survival. Preoperative biopsy (PB) and intraoperative frozen section (FS) are usually used to guide surgical staging on which the choice of adjuvant therapy will be based successively.

OBJECTIVE

The aim of this study was to assess the agreement rate between PB and FS with final diagnosis (FD) in a series of surgically resected EC.

MATERIALS

All patients submitted to hysterectomy for EC or atypical endometrial hyperplasia in the Reggio Emilia Province hospitals from 2007 to 2018 were included. Concordance rate differences in histotype, grading, myoinvasion, risk of recurrence between PB, FS and FD were assessed with Fisher's exact test and Mc Nemar contingency test.

RESULTS

A total of 352 patients were identified. For 345 patients it was possible to compare PB and FD results. FS examination was performed in 201/352 (57%) cases, while for 21/352 (6%) patients only an intraoperative macroscopic evaluation was done; in the remaining women, FS-exam was omitted. In 14/201 (7%) cases the tumor wasn't grossly identifiable and the random FS-sampling wasn't able to find the tumor site. High diagnostic concordance of tumor type between PB and FD was observed: no significant differences were registered in type 1 and type 2-endometrial cancer identification (83%, 73%, p = 0.121). Significant differences (p = 0.005) were observed comparing FS and FD results: 95% of type 1-ECs were correctly diagnosed by FS, while only 76% of type 2-ECs received a correct diagnosis on FS. PB showed a concordance with FD among tumor grading close to 55% whilst concordance achieved 71% grouping low grade (G1-G2) EC. No significant differences in FS and FD concordance rate were observed between tumor grades. Concordance for low grade was significantly higher than for high grade ECs (89% vs 50%, respectively, p value = 0.014). The concordance rate in evaluating the myoinvasion status between FS and FD was 80% (n: 199 patients), reaching 99% after combining the first 2 groups (0-49% vs ≥ 50%). Twenty-two cases underwent only intraoperative macroscopic evaluation of the myoinvasion, with an accuracy of 91%: only in 1 case the invasion of the cervical stroma was not detected (Stage II), and 1 case the patient was overstaged as Ib. Discrepancies were observed in FS capacity to correctly predict the final ESMO risk group in stage I patients: FS resulted particularly reliable in predicting a low-risk (concordance with FD: 91%) while the accuracy sharply decreased for intermediate- and high-risk patients (62% and 40%, respectively). To investigate the usefulness of FS in EC management, we compared patients who underwent FS (FS-group) or not (no-FS-group). Especially for low risk patients, the FS significantly increased the adequacy of surgical treatment from 53% (no-FS-group) to 72% (FS-group) (p = 0.016).

CONCLUSIONS

FS remains a useful tool to tailor surgery in EC-patients, avoiding secondary surgery to complete staging particularly in patients with AH + AHBA, low and intermediate risk ECs that could benefit from adjuvant therapy.

[Borderline ovarian tumours: CNGOF Guidelines for clinical practice - Biopathology of ovarian borderline tumors]

OBJECTIVES

Ovarian borderline tumors (OBT) represent a heterogeneous group of lesions with specific management for each histological subtype. Thus, the correct histological diagnosis is mandatory.

MATERIAL AND METHODS

References were searched by PubMed from January 2000 to January 2018 and original articles in French and English literature were selected.

RESULTS AND CONCLUSIONS

OBT should be classified according to the last WHO classification. Any micro-invasion (foci<5mm) or microcarcinoma (foci<5mm with nuclear atypia and desmoplastic stromal reaction) should be indicated in the pathology report. In case of serous OBT, variants (classical or the micropapillary/cribriform) should be indicated (grade C). The peritoneal implants associated with OBT, should be classified as invasive or noninvasive, according to the extension into the underlying adipous tissue. If no adipous tissue is seen the term undetermined should be used (grade B). In case of mucinous OBT bilateral and/or with peritoneal implants or peritoneal pseudomyxoma a search for primitive gastrointestinal, appendiceal or biliopancreatic tumor should be performed (grade C). In case of OBT, a thorough sampling of the tumor is recommended, with 1 block/cm and 2 blocks/cm in case of mucinous OBT, serous OBT micropapillary variant, OBT with intraepithelial carcinoma or/and micro-invasion. Peritoneal implants should be examined in toto. Omentum without macroscopic lesion should be sampled in 4 to 6 blocks (grade C). In case of ovarian cyst suspicious for OBT, fine needle aspiration is not recommended (grade C). In case of ovarian tumor suspicious for OBT, intraoperative examination should be performed by a gynecological pathologist (grade C).

Margin Practices in Oral Cavity Cancer Resections: Survey of American Head and Neck Society Members

OBJECTIVES/HYPOTHESIS

To investigate the definition of a clear margin and the use of frozen section (FS) among practicing head and neck surgeons in oral cancer management.

STUDY DESIGN

Cross-sectional survey.

METHODS

We designed a survey that was sent to American Head and Neck Society (AHNS) members via an email link.

RESULTS

A total of 185 (13% of 1,392) AHNS members completed our survey. Most surgeons surveyed (96.8%) use FS to supplement oral cavity squamous cell carcinoma resections. Fifty-five percent prefer a specimen-based approach. The majority of respondents believe FS is efficacious in guiding re-resection of positive margins, with 81% considering the new margin to be negative. More than half of respondents defined a distance of >5 mm on microscopic examination as a negative margin.

CONCLUSIONS

To avoid oral cancer resections that result in positive margins on final analysis, and thus the need for additional therapy, most surgeons surveyed use FS. A majority of surveyed surgeons now prefer a specimen-based approach to margin assessment. Although there is a debate on what constitutes a negative margin, most surgeons surveyed believe it to be >5 mm on microscopic examination.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:782-787, 2021.

Signet-ring cell appearance of atrophic fat cells

Cells with 'signet-ring' appearance were found at post-mortem examination of a man with a history of chronic illness, weight loss and multiple regions of 'bowel thickening' during life. Due to the decedent's history, the finding raised the possibility of disseminated signet-ring adenocarcinoma. However, the vacuoles did not stain for mucin and the cells did not stain for keratin. The cells did stain for calretinin and so a diagnosis of signet ring mesothelioma was considered. However, it was suggested that the cells with a cytoplasmic vacuole displacing the nucleus to one side producing the signet-ring appearance were instead atrophic fat cells. This was subsequently proven by Oil Red O staining.

Real-Time Intraoperative Consultation Reporting in the Electronic Health Record

Objectives

We sought to make pathologists’ intraoperative consultation (IOC) results immediately available to the surgical team, other clinicians, and laboratory medicine colleagues to improve communication and decrease postanalytic errors.

Methods

We created an IOC report in our stand-alone laboratory information system that could be signed out prior to, and independent of, the final report, and transfer immediately to the electronic health record (EHR) as a preliminary diagnosis. We evaluated two metrics: preliminary (IOC) result review in the EHR by clinicians and postanalytic errors.

Results

We assessed 2,886 IOC orders from the first 22 months after implementation. Clinicians reviewed 1,956 (68%) of the IOC results while in preliminary status, including 1,399 (48%) within the first 24 hours. We evaluated 150 cases preimplementation and 300 cases postimplementation for discrepancies between the pathologist’s IOC result and the IOC result recorded by the surgeon in the operative note. Discrepancies dropped from 12 of 150 preimplementation to 6 of 150 and 7 of 150 in postimplementation years 1 and 2. One of the 25 discrepancies had a major clinical impact.

Conclusions

Real-time reporting of IOC results to the EHR reliably transmits results immediately to clinical teams. This strategy reduces but does not eliminate postanalytic interpretive errors by clinical teams.

Four-Year Experience of Digital Slide Telepathology for Intraoperative Frozen Section Consultations in a Two-Site French Academic Department of Pathology

OBJECTIVES

To share our experience with digital slide telepathology for intraoperative frozen section consultations (IOCs) and to describe its evolution over time by reporting performance metrics and addressing organizational and economic aspects.

METHODS

Since 2013, a technician has been alone at the surgical site. At the other site, the pathologist opens the digital slide from a local server via the intranet. Three periods were compared: a 6-month period of conventional IOC (period 1), a 24-month period of telepathology at 6 months after implementation (period 2), and a 12-month period of telepathology at 3.5 years after implementation (period 3).

RESULTS

In total, 87 conventional IOCs and 464 and 313 IOCs on digital slides were performed respectively during periods 1, 2, and 3; mean turnaround time was 27, 36, and 38 minutes, respectively, and there were a mean number of 1.1, 1.1, and 1.3 slides, respectively, per IOC. Diagnostic accuracy was achieved in 95.4%, 92.7%, and 93.9%, respectively, of IOCs (not significant). The additional cost is in the same range as the cost of urgent transport by courier.

CONCLUSIONS

Developing IOC with digital slides is a challenge but is necessary to optimize medical time in the current context of pathologist shortage and budget restrictions.

Rule-based automatic diagnosis of thyroid nodules from intraoperative frozen sections using deep learning

Frozen sections provide a basis for rapid intraoperative diagnosis that can guide surgery, but the diagnoses often challenge pathologists. Here we propose a rule-based system to differentiate thyroid nodules from intraoperative frozen sections using deep learning techniques. The proposed system consists of three components: (1) automatically locating tissue regions in the whole slide images (WSIs), (2) splitting located tissue regions into patches and classifying each patch into predefined categories using convolutional neural networks (CNN), and (3) integrating predictions of all patches to form the final diagnosis with a rule-based system. To be specific, we fine-tune the InceptionV3 model for thyroid patch classification by replacing the last fully connected layer with three outputs representing the patch's probabilities of being benign, uncertain, or malignant. Moreover, we design a rule-based protocol to integrate patches' predictions to form the final diagnosis, which provides interpretability for the proposed system. On 259 testing slides, the system correctly predicts 95.3% (61/64) of benign nodules and 96.7% (148/153) of malignant nodules, and classify 16.2% (42/259) slides as uncertain, including 19 benign and 16 malignant slides, which are a sufficiently small number to be manually examined by pathologists or fully processed through permanent sections. Besides, the system allows the localization of suspicious regions along with the diagnosis. A typical whole slide image, with 80, 000 × 60, 000 pixels, can be diagnosed within 1 min, thus satisfying the time requirement for intraoperative diagnosis. To the best of our knowledge, this is the first study to apply deep learning to diagnose thyroid nodules from intraoperative frozen sections. The code is released at https://github.com/PingjunChen/ThyroidRule.

Sentinel lymph node mapping and intraoperative assessment in a prospective, international, multicentre, observational trial of patients with cervical cancer: The SENTIX trial

BACKGROUND

SENTIX (ENGOT-CX2/CEEGOG-CX1) is an international, multicentre, prospective observational trial evaluating sentinel lymph node (SLN) biopsy without pelvic lymph node dissection in patients with early-stage cervical cancer. We report the final preplanned analysis of the secondary end-points: SLN mapping and outcomes of intraoperative SLN pathology.

METHODS

Forty-seven sites (18 countries) with experience of SLN biopsy participated in SENTIX. We preregistered patients with stage IA1/lymphovascular space invasion-positive to IB2 (4 cm or smaller or 2 cm or smaller for fertility-sparing treatment) cervical cancer without suspicious lymph nodes on imaging before surgery. SLN frozen section assessment and pathological ultrastaging were mandatory. Patients were registered postoperatively if SLN were bilaterally detected in the pelvis, and frozen sections were negative.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT02494063).

RESULTS

We analysed data for 395 preregistered patients. Bilateral detection was achieved in 91% (355/395), and it was unaffected by tumour size, tumour stage or body mass index, but it was lower in older patients, in patients who underwent open surgery, and in sites with fewer cases. No SLN were found outside the seven anatomical pelvic regions. Most SLN and positive SLN were localised below the common iliac artery bifurcation. Single positive SLN above the iliac bifurcation were found in 2% of cases. Frozen sections failed to detect 54% of positive lymph nodes (pN1), including 28% of cases with macrometastases and 90% with micrometastases.

INTERPRETATION

SLN biopsy can achieve high bilateral SLN detection in patients with tumours of 4 cm or smaller. At experienced centres, all SLN were found in the pelvis, and most were located below the iliac vessel bifurcation. SLN frozen section assessment is an unreliable tool for intraoperative triage because it only detects about half of N1 cases.

Pretracheal-laryngeal lymph nodes in frozen section predicting contralateral paratracheal lymph nodes metastasis

BACKGROUND

There has been an ongoing debate concerning the predictors of contralateral paratracheal lymph nodes metastasis (LNM) in unilateral papillary thyroid cancer (PTC). This study aimed to explore the value of pretracheal-laryngeal lymph nodes (LNs) in frozen section in predicting contralateral paratracheal LNM.

METHODS

A total of 242 patients with unilateral PTC were enrolled in this prospective study. Patients who underwent total thyroidectomy and bilateral central lymph nodes dissection (LND) were divided into two groups according to positive or negative contralateral paratracheal LNs. Patients' demographics and clinicopathological features were compared between the two groups. Validity indexes and consistency of pretracheal-laryngeal LNs in frozen sections were calculated.

RESULTS

LNM rates in central, ipsilateral paratracheal, pretracheal-laryngeal, and contralateral paratracheal regions were 55.37%, 47.03%, 23.55% and 14.05%, respectively. Only pretracheal-laryngeal LNM, regardless of whether detected in frozen or paraffin sections, were independent risk factors for contralateral paratracheal LNM (OR = 2.707; 95% CI 1.062-6.902; P = 0.037 in frozen section; OR = 3.072; 95% CI 1.248-7.560; P = 0.015 in paraffin section). The sensitivity, specificity, false-negative rate, false-positive rate, accuracy rate, and Kappa value of pretracheal-laryngeal LNM in frozen sections for predicting pretracheal-laryngeal LNM were 87.72%, 100%, 12.28%, 0%, 97.11% and 0.916 respectively, while those for predicting contralateral paratracheal LNM were 85,29%, 89.90%, 14.71%, 10.10%, 89.22%, and 0.618 respectively.

CONCLUSION

Pretracheal-laryngeal LNs in frozen section accurately predicted contralateral paratracheal LNM, which could allow the identification of patients who can benefit from an extended central LND.

An Update on Surgical Margins in the Head Neck Squamous Cell Carcinoma: Assessment, Clinical Outcome, and Future Directions

PURPOSE OF REVIEW

Failure to achieve tumor-free margins is the single largest cause of death for head neck cancer patients. At the same time, it is the only factor that is in complete control of the surgeon. This review summarizes evidence for the definition, clinical implications, and methods to achieve optimal margins.

RECENT FINDINGS

The previous universally followed definition of adequate margin (5 mm in final histopathology) has been disputed. Various biological, optical, and imaging adjuncts can aid in achieving optimal margins. Extent of resection and margins in human papilloma virus (HPV)-positive oropharyngeal cancers and following induction chemotherapy remain controversial. Though practiced widely, frozen section-guided margin revision has not conclusively shown improved local control rates. The role of molecular assessment of margins is promising but not established. The definition of adequate margin differs according to the site in the head neck region. Currently, the 5-mm margin at final histopathology is the most commonly accepted definition of an "adequate" margin.