Cytologic-histologic Correlation Research Articles

Application of the Milan System for Reporting Salivary Gland Cytopathology: A Single Institutional Experience of 354 Cases with Cytologic-Histologic Correlation

Background: Evaluation of salivary gland lesions is routinely done preoperatively by fine-needle aspiration cytology (FNAC). The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC), with diagnostic categories I–VI, has been recommended to standardize the reporting of salivary gland lesions by FNAC. We aimed to reclassify archival salivary gland FNAC samples using MSRSGC, correlate the samples with surgical resections, and calculate the risk of malignancy (ROM) for each category. Methods: A total of 354 salivary gland FNAC samples (2013–2018) were reviewed. All FNAC results were retrospectively classified according to the MSRSGC. All cases had surgical follow-up. Histology was used to calculate the ROM, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy. Results: The 354 aspirates were classified as: nondiagnostic (ND) 17.0% (60), non-neoplastic (NN) 1.4% (5), atypia of undetermined significance (AUS) 11.0% (39), benign neoplasm (BN) 49.4% (175), salivary gland neoplasms of unknown malignant potential (SUMP) 10.7% (38), suspicious for malignancy (SM) 3.4% (12), and malignant (M) 7.1% (25). The ROM was as follows: ND 22%, NN 20%, AUS 15%, BN 2%, SUMP 53%, SM 75%, and M 96%. The diagnostic accuracy for separating benign versus malignant neoplasms was 96%. Cytologic-histologic correlation yielded a false-negative rate of 2.7%, false-positive rate of 10.5%, PPV of 89%, NPV of 97%, sensitivity of 87%, and specificity of 98%. Conclusion: MSRSGC helps standardize cytology reports, provides useful information for appropriate clinical management, and ensures the best care of patients with salivary gland lesions.

Malignant Cells in Urine Cytology: Not Always High-Grade Urothelial Carcinoma

Abstract The main purpose of urine cytology is the detection of high-grade urothelial carcinoma (HGUC). When malignant cells of nonurothelial origin are present, it is often misdiagnosed as HGUC due to the rarity of this event and difficulty in distinguishing subtle cytomorphologic differences. To arrive at the appropriate diagnosis, evaluation of urine cytology specimens requires correlation with clinical and radiologic findings and utilization of cytologic-histologic correlation. We present the case of a 64-year-old woman with gross hematuria. Imaging located an infiltrative mass involving the left renal pelvis, highly suggestive of urothelial carcinoma. Lymphadenopathy and multiple bony lesions in the spine were concerning for metastatic disease. Urine cytology specimens taken during cystoscopy contained malignant cells, which were interpreted as HGUC. The workup of a subsequent lymph node biopsy showed a metastatic high grade carcinoma of renal origin with SMARCB1 loss. This finding led to the reexamination of the urine cytology specimens, revealing the malignant cells were not HGUC but rather renal carcinoma. This case highlights a potential pitfall in the evaluation of urine cytology and the importance of cytologic-histologic correlation.

Current State of Cytologic-Histologic Correlation Implementation for North American and International Laboratories: Results of the College of American Pathologists Cytopathology Committee Laboratory Practices in Gynecologic Cytology Survey.

The College of American Pathologists (CAP) updated the Laboratory Accreditation Program Cytopathology Checklist to assist laboratories in meeting and exceeding the Clinical Laboratory Improvement Amendments standards for gynecologic cytologic-histologic correlation (CHC). To survey the current CHC practices. Data were analyzed from a survey developed by the committee and distributed to participants in the CAP Gynecologic Cytopathology PAP Education Program mailing. Worldwide, CHC practice is nearly universally adopted, with an overall rate of 87.0% (568 of 653). CHC material was highly accessible. CHC was commonly performed real time/concurrently at the time the corresponding surgical pathology was reviewed. Investigation of CHC discordances varied with North American laboratories usually having a single pathologist review all discrepant histology and cytology slides to determine the reason for discordance, while international laboratories have a second pathologist review histology slides to determine the reason for discordance. The cause of CHC discordance was primarily sampling issues. The more common statistical metrics for CHC monitoring were the total percentage of cases that correlated with subsequent biopsies, screening error rate by cytotechnologist, and interpretative error rate by cytotechnologist. Many laboratories have adopted and implemented the CHC guidelines with identifiable differences in practices between North American and international laboratories. We identify the commonalities and differences between North American and international institutional practices including where CHC is performed, how CHC cases are identified and their accessibility, when CHC is performed, who investigates discordances, what discordances are identified, and how the findings affect quality improvement.

Application of the Milan System for Reporting Salivary Gland Cytopathology in pediatric patients: An international, multi-institutional study.

Pediatric salivary gland fine-needle aspiration (FNA) is uncommon with a higher frequency of inflammatory lesions and a small proportion of malignancies. This international, multi-institutional cohort evaluated the application of the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) and the risk of malignancy (ROM) for each diagnostic category. Pediatric (0- to 21-year-old) salivary gland FNA specimens from 22 international institutions of 7 countries, including the United States, England, Italy, Greece, Finland, Brazil, and France, were retrospectively assigned to an MSRSGC diagnostic category as follows: nondiagnostic, nonneoplastic, atypia of undetermined significance (AUS), benign neoplasm, salivary gland neoplasm of uncertain malignant potential (SUMP), suspicious for malignancy (SM), or malignant. Cytology-histology correlation was performed where available, and the ROM was calculated for each MSRSGC diagnostic category. The cohort of 477 aspirates was reclassified according to the MSRSGC as follows: nondiagnostic, 10.3%; nonneoplastic, 34.6%; AUS, 5.2%; benign neoplasm, 27.5%; SUMP, 7.5%; SM, 2.5%; and malignant, 12.4%. Histopathologic follow-up was available for 237 cases (49.7%). The ROMs were as follows: nondiagnostic, 5.9%; nonneoplastic, 9.1%; AUS, 35.7%; benign neoplasm, 3.3%; SUMP, 31.8%; SM, 100%; and malignant, 100%. Mucoepidermoid carcinoma was the most common malignancy (18 of 237; 7.6%), and it was followed by acinic cell carcinoma (16 of 237; 6.8%). Pleomorphic adenoma was the most common benign neoplasm (95 of 237; 40.1%). The MSRSGC can be reliably applied to pediatric salivary gland FNA. The ROM of each MSRSGC category in pediatric salivary gland FNA is relatively similar to the ROM of each category in adult salivary gland FNA, although the reported rates for the different MSRSGC categories are variable across institutions.

Cervical Cytology-Histology Correlation Based on the American Society of Cytopathology Guideline (2017) at the Russian National Medical Research Center for Obstetrics, Gynecology, and Perinatology.

Recent evidence suggests that a cytology–histology correlation (CHC) with discrepancy detection can both evaluate errors and improve the sensitivity and specificity of the cytologic method. We aimed to analyze the errors in cytologic–histologic discrepancies according to the CHC protocol guideline of the American Society of Cytopathology (2017). This retrospective study included 273 patients seen at the National Medical Research Center of Obstetrics, Gynecology and Perinatology (Moscow, Russia) between January 2019 and September 2021. The patients’ mean age was 34 ± 8.1 years. The cytology–histology agreement was noted in 158 cases (57.9%). Major discrepancies were found in 21 cases (7.6%), while minor discrepancies were noted in 93 cases (34.1%). The reason for 13 (4.8%) discrepancies was a colposcopy sampling error and, in 46 (16.8%) cases, the reason was a Papanicolaou (PAP) test sampling error. The discrepancy between primary and reviewed cytology was due interpretive errors in 13 (4.8%) cases and screening errors in 42 (15.4%) cases. We demonstrated that the ASC guidelines facilitate cervical CHC. A uniform application of these guidelines would standardize cervical CHCs internationally, provide a scope for the inter-laboratory comparison of data, and enhance self-learning and peer learning.

Successful integration of thyroid cytopathology and surgical pathology education in an E-module format

ContextThe shift to digital learning in medicine is well underway and in fact spurred by the COVID-19 pandemic. The didactic portion of our institution's cytotechnology (CT) education program is online and delivered to learners across the nation. With CT education elevating to the master’s degree level, there is a need to expand cytologic correlation with surgical resection specimens. We also wanted to afford pathology residents the same. MethodsWe developed an online cytologic–histologic correlation digital learning module (e-module) addressing thyroid fine needle aspirations (FNAs) and surgical thyroidectomy specimens which was administered as part of coursework in the CT education and pathology residency programs. The module was 35 min long and consisted of guided narration with both formative and summative interactive quizzes. After completion of the module, participants were invited to fill a brief survey comprised of multiple choice, Likert, and free response questions. This study was approved by the institutional review board. ResultsThe 29 respondents were comprised of 22 CT students and 7 residents. CT students had minimal experience thyroid pathology prior to the module; residents were mixed. Twenty-three (79.3%) ranked the highest tiers for learning cytopathology through this module, 24 (82.8%) for learning thyroid surgical pathology, and 25 (86.2%) for cytologic–histologic correlation. All respondents stated they would like similar activities in the future. ConclusionsTeaching cytology–histology correlation for thyroid in an electronic format was effective and well-received by participants. There is a demand for these activities among current learners, suggesting that expanding the available repertoire will be beneficial.

Accuracy of the Milan System for Detecting Neoplastic vs Non-Neoplastic Salivary Gland Lesions: A Retrospective Review

Abstract Introduction/Objective Overlapping morphology and heterogeneity of salivary gland tumors (SGT) poses a diagnostic challenge. FNA is commonly used diagnostic tool for evaluation of superficial and deep lesions of any site, but above limitations restrict its maximum utility. To standardize reporting and to address above limitations, Milan system (MS) of reporting salivary gland cytology, has been developed and implemented by labs. We conducted a retrospective study, applying MS to salivary gland lesions (SGL) to evaluate its accuracy and usefulness in discriminating between neoplastic and non-neoplastic conditions, and thus directing patient management (PM) Methods/Case Report 10 yr retrospective review was performed to include patients with FNA for SGL, cytology diagnosis categorized using MS, cytology-histology (CH) correlation performed, and patients’ charts reviewed for follow up. Attention given to diagnostic discrepancies between MS categories and the histologic diagnosis Results (if a Case Study enter NA) 152 patients (20-88yrs) were retrieved, peak incidence 40-49 yrs; M:F ratio 1.2:1. Distribution of the cases in the MS categories: Non-diagnostic (ND) 24, Non-neoplastic (NN) 33, Atypia of Undetermined Significance (AUS) 4, Neoplasm (N) 71, Suspicious for malignancy (SUN) 7, and Malignant (M) 10. 60 cases identified with follow-up histology, of which 51 cases were correlated, distributed as 4 ND, 4 NN, 0 AUS, 37 N, 3 SUN, and 3 M. The uncorrelated 9 cases were distributed as 4 ND due to scant sampling; 2 NN, histologically Warthin’s tumor and sialolipoma; 2 AUS, histologically basal cell neoplasm and infarcted Warthin’s tumor; 1 malignant, histologically cystic mucoepidermoid carcinoma; 0 cases for neoplastic and suspicious for malignancy categories Conclusion Milan System is a useful cytologic tool for diagnosing and segregating patients with salivary gland pathologies, however, our study shows MS to be more reliable diagnostic tool with higher accuracy (combined 98%) in N, SUN & M categories as compared to ND, NN & AUS categories (combined 50%)

Are We Still Learning from the CLIA-mandated Cytology-histology Correlation in Gynecological Pathology? Is it Time to Revisit This Mandate?

Are We Still Learning from the CLIA-mandated Cytology-histology Correlation in Gynecological Pathology? Is it Time to Revisit This Mandate?

Human telomerase RNA component (hTERC) gene expression and chromosome 7 ploidy correlate positively with histological grade of cervical intraepithelial neoplasia.

Cervical cancer screening by primary human papilloma virus detection and cytology is fraught with low specificity and variable sensitivity, respectively. Cytology-histology correlation remains modest. Biomarkers associated with early genetic events in cervical squamous carcinogenesis and detectable in cytology material are likely to be relevant. Human telomerase RNA component (hTERC) gene overexpression and aneuploidy are promising candidates in view of their reported early and consistent association with cervical squamous oncogenesis. We analysed hTERC gene expression and chromosome 7 ploidy by fluorescent in-situ hybridisation (FISH) in 50 women with cytological precursor squamous intraepithelial lesions and available histology outcomes. Results were expressed as percentages of cells showing ≥3 signals, mean signals/nucleus, and maximum amplitude across various cytology and histology categories. Proportions of positive cases were calculated from threshold values derived from 6 controls. Distribution of above indices with respect to ≥cervical intraepithelial neoplasia 2 (CIN2) was explored. For both genetic aberrations, there was significant positive correlation (for all indices) between the proportion of positive cases and worsening cytological and histological outcomes (P<.05), with significant intergroup differences (P<.05). High-grade lesions (≥CIN2) had significantly higher results compared to <CIN2 lesions (P≤.001). In five discordant cases with ≥CIN2 under- or overdiagnosed on cytology, FISH supported the histological diagnosis. HTERC gene amplification and chromosome 7 ploidy showed positive association with cervical squamous carcinogenesis and could be relevant in settings of discrepant cytology-histology correlation.

Pediatric fine-needle aspiration cytology: An audit of 266 cases of pediatric tumors with cytologic-histologic correlation.

Objectives:Fine-needle aspiration cytology (FNAC), a well-accepted minimally invasive diagnostic technique utilized in adults, is gradually gaining ground for pediatric patients as well. However, there are very few comprehensive reports in the literature on utility of FNA in pre-operative diagnosis of pediatric tumors.Material and Methods:An observational study was conducted at a cancer research center and a pediatric tertiary care hospital over a 5-year period. A cytologic-histologic correlation was performed for FNACs performed in pediatric patients for a clinical diagnosis of neoplastic lesions at both the centers. Relevant clinical details and histopathology, wherever available, were retrieved. Sensitivity, specificity, and accuracy of FNAC in diagnosis of malignant lesion were calculated from the cases with available histologic correlation.Results:Of the 266 cases included, there was a slight male predominance with lymphadenopathy being the most common presentation and non-Hodgkin’s lymphoma as the most frequent diagnosis in cases clinically suspected to have a neoplasm. Histologic correlation was available in 112 cases with 100% concordance in liver and kidney tumors. Few rare cytologic diagnoses such as papillary renal cell carcinoma, mesenchymal hamartoma of the liver, and thymolipoma could be accurately rendered on FNAC smears in conjunction with the clinic-radiologic features. The sensitivity, specificity, and accuracy of FNA in diagnosing malignant pediatric tumors were found to be 100%, 92.6%, and 97.7%, respectively.Conclusion:The present study underscores the high sensitivity and accuracy of FNAC in diagnosis of pediatric tumors, both in superficial and deep-seated locations. Awareness of the cytomorphologic features and clinic-radiologic correlation may assist the cytopathologists in rendering a precise diagnosis of rare pediatric tumors as well.

Cytology-Histology Correlation of Hydatid Cyst: A Case Study and Literature Review

Abstract Casestudy: Hydatid cyst results when humans get infected by ingesting the eggs of Echinococcus Granulosus. Upon release, the six-hooked oncospheres penetrate the intestinal wall and migrate via circulation to various organs, mostly liver and lung. Here, they develop into hydatid cyst. The cyst enlarges gradually and is filled with daughter cysts and protoscolices. We report the case of a 69-year old female, native of Uzbekistan, who presented with right upper quadrant pain. Imaging showed a 20 cm liver cyst and multiple pelvic cysts with a stage of CE2 implying that they were most likely functional. Serum Echinococcal antibody was positive. After 2 months of Albendazole treatment, there was no radiological change. The patient underwent laparoscopic puncture aspiration and injection with 20% saline (PAIR) and pericystectomy of the pelvic cysts. The aspirate revealed scattered scolices, inflammatory cells and abundant amorphous debris consistent with hydatid cyst. Bilateral 5-cm pelvic cysts had pale yellow, soft to firm walled, multiple cavities. Microscopy revealed a fibrofatty outermost layer with chronic inflammation and a two-layered cyst wall including a thin germinal epithelium covered by a thick acellular outer membrane. Multiple parasites, some degenerate (dense eosinophilic) were present, confirming the cytologic diagnosis of cystic echinococcosis. Following further treatment with Albendazole, she underwent a robotic assisted PAIR and partial peri-cystectomy of the liver cyst with repair of the duct to cyst communication. The liver cyst contained daughter cysts of Echinococcus and brood capsule with protoscolices. After 2 months more of Albendazole her Elisa was intermediate. A prior study reported cytopathologic diagnosis of hydatid cyst in 17 patients evaluated for various masses. Our case highlights the role of cytology sampling in confirming the diagnosis of hydatid disease. Potentially fatal in untreated patients, this entity has to be considered in the differential diagnosis of cystic lesions.

Retrospective Analysis of Pleural Fluid Cytology Specimens in an Academic Hospital Center: Cytologic-Histologic Correlation and Discrepancy Analysis

Retrospective Analysis of Pleural Fluid Cytology Specimens in an Academic Hospital Center: Cytologic-Histologic Correlation and Discrepancy Analysis

Peritoneal Fluid Cytology: A Single Institutional Experience with Focus on Cytology-Histology Correlation and Incorporation of the International System for the Reporting of Serous Fluid Cytopathology

Peritoneal Fluid Cytology: A Single Institutional Experience with Focus on Cytology-Histology Correlation and Incorporation of the International System for the Reporting of Serous Fluid Cytopathology

Urinary tract cytology: a cytologic-histopathologic correlation with The Paris System, an institutional study

Urothelial carcinoma (UC) requires lifelong monitoring, commonly through urinary cytology and cystoscopy. Urine cytology has a relatively high sensitivity for detecting high-grade urothelial carcinoma (HGUC); however, its sensitivity for low-grade urothelial neoplasm (LGUN) is significantly lower with wide interobserver variability. The Paris System (TPS) was proposed to create standardized diagnostic categories with defined cytomorphologic criteria. We attempt to evaluate diagnostic efficacy of identifying UC using TPS through cytologic-histologic correlation. A retrospective search identified 170 cases of urine cytology cases with concurrent biopsies collected during a 2-year time period at University of Rochester Medical Center. Patient age, sex, smoking history, prior malignancy diagnoses, cystoscopy findings, specimen collection method, UroVysion results, and 1-year follow-up of surgical pathology cases were included. Cytologic-histologic correlation was identified in 59% of cases, with 18% true positives and 41% true negatives. Discordant results were identified in 41% of cases; of these, 4% were false positives, 11% false negatives, 12% potential sampling bias, and 14% were low-grade urothelial carcinoma (LGUC). The analysis of this 2-year study finds a positive predictive value of urine cytology for HGUC to be 81%, a negative predictive value of 79%, a sensitivity of 61%, a specificity of 91%, and an accuracy of 79%. Our results support TPS's ability to improve the reliability and accuracy of interpretations in urine cytology for HGUC. Nevertheless, additional studies are essential to improve the diagnostic accuracy of LGUN, and urine adequacy, in order to improve patient care and early detection, while identifying potential sampling bias.

An overview of thyroid fine-needle aspiration practice in Myanmar.

Fine-needle aspiration cytology (FNAC) of the thyroid is a widely accepted method for aiding the diagnosis of thyroid nodules. In Myanmar, it has been done since the early 1990s, and mainly performed by surgeons and otorhinolaryngologists. The interpretation of cytology is solely made by pathologists. Although some of the experts particularly those from specialist hospitals use the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC), many still prefer the British five-tier cytopathology report. Available local publications addressing the accuracy of FNAC and cytologic-histologic correlations were queried. Ten studies performed in 1991-2018 on 540 thyroid nodules were included. Cytologic-histologic correlations showed a range of sensitivity from 64.29% to 100%, specificity from 93% to 100%, and diagnostic accuracy from 94% to 100%. The adoption of TBSRTC by pathologists is still slow and should be encouraged via seminars and training programs. Further multihospital-based large cohort studies with uniform design and adequate follow-up are needed to better promote and assess utility of thyroid FNAC in Myanmar.

The Milan System for Reporting Salivary Gland Cytopathology: Benefits and Cautions

Abstract Fine-needle aspiration (FNA) is a well-established procedure for the diagnosis and management of salivary gland lesions despite challenges imposed by their diversity, complexity, and cytomorphological overlap. Until recently, the reporting of salivary gland FNA specimens was inconsistent among different institutions throughout the world, leading to diagnostic confusion among pathologists and clinicians. In 2015, an international group of pathologists initiated the development of an evidence-based tiered classification system for reporting salivary gland FNA specimens, the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC). A corresponding MSRSGC Atlas was published in February 2018. The MSRSGC consists of 6 diagnostic categories that incorporate the morphologic heterogeneity and overlap among various nonneoplastic, benign, and malignant lesions of the salivary glands. In addition, each diagnostic category is associated with a risk of malignancy and management recommendations. The main goal of the MSRSGC is to improve communication between cytopathologists and treating clinicians, while also facilitating cytologic-histologic correlation, quality improvement, and sharing of data from different laboratories for research. Herein, we review the benefits and the limitations of the MSRSGC, as well as the challenges of implementing this new reporting system in routine practice.

The importance of risk of neoplasm as an outcome in cytologic-histologic correlation studies on thyroid fine needle aspiration.

The introduction of noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) altered the practice of thyroid pathology and reduced the risk of malignancy (ROM) associated with the indeterminate categories in the Bethesda system for reporting thyroid cytopathology (TBSRTC). It has been proposed that the evaluation of the risk of neoplasm (RON) is important in cytologic-histologic correlation studies. A total of 5224 thyroid aspirates were performed at our institution during an 8-year period. Of the 1475 cases (28%) with surgical follow-up, the histologic diagnoses comprised benign non-neoplastic (BNN, n = 669), follicular adenoma (FA, n = 188), NIFTP (n = 42), papillary microcarcinoma (PMC) (n = 223), and malignant neoplasm excluding PMC (n = 353). The RON was calculated to include neoplasia with low risk biologic behavior (FA, NIFTP, PMC) and malignant neoplasms. In contrast, the ROM was reserved for malignant neoplasms excluding PMC. The RON for each TBSRTC category was: nondiagnostic (ND) 38.3%, benign 20.9%, atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) 63.2%, follicular neoplasm or suspicious for follicular neoplasm (FN/SFN) 83.9%, suspicious for malignancy (SFM) 94%, and malignant 100%. The ROM excluding PMC was: ND 14%, benign 1.6%, AUS/FLUS 17.8%, FN/SFN 28.4%, SFM 84.4%, and malignant 99.5%. The RON and ROM support the recommended management guidelines from TBSRTC for all categories, except for FN/SFN. Histopathologic follow-up of FN/SFN aspirates in our study contain a very high rate of neoplasm (83.9%), which might support the management preference of conservative surgery.

Targeted education as a method for reinforcing Paris System criteria and reducing urine cytology atypia rates

The Paris System for Urine Cytology (TPS) provides well-defined diagnostic criteria for the category of atypical urothelial cells (AUC). The current study compares the rate of AUC diagnoses at a large academic medical center before and after an educational intervention (EI) by a urine cytology expert. An expert in TPS delivered an educational intervention consisting of an interactive microscope session and a didactic session that focused on the AUC diagnostic category. The number of urine cytology cases, the AUC rate, and the false-negative percentage were calculated before and after the EI, using the electronic medical records and cytologic-histologic correlation records. A total of 4026 urine cytology cases were signed out in the 25 months prior to the educational intervention and 1585 cases were signed out in the 10 months after the intervention. EI had a significant impact on diagnostic categorization, including a reduction in AUC (19.6% versus 12.5%) and suspicious for high-grade urothelial carcinoma (3.9% versus 3.1%) diagnoses. The cytotechnologists also placed fewer cases into the AUC category during primary screening (27.6% versus 23.0%). Although a higher percentage of cases was reported as negative for high-grade urothelial carcinoma, the false-negative rate did not significantly change after the intervention (1.8% versus 2.0% of negative cases, P = 0.65). Focused educational sessions for pathologists and cytotechnologists on the diagnostic criteria for AUC as defined by TPS can significantly reduce the rate of atypical diagnoses without a significant increase in the rate of false negatives.

The value and practical utility of intraoperative touch imprint cytology of sentinel lymph node(s) in patients with breast cancer: A retrospective cytology-histology correlation study.

Objective:Intraoperative evaluation of sentinel lymph nodes (SLNs) for patients with breast cancer is widely performed with frozen section (FS), cytology, or a combination of both. Touch imprint cytology (TIC) reportedly has an equivalent sensitivity to FS. We studied its diagnostic utility to detect SLN metastases.Materials and Methods:Cases of 367 patients with breast cancer who underwent intraoperative valuation of SLNs (507 LNs) were evaluated. All FS and corresponding TIC slides of SLNs of each case were reviewed microscopically for the presence of metastases of any size. If present, the metastatic focus was measured on the FS.Results:Of these 507 SLNs, 82 LNs (16.2%) from 69 women were found to have metastases in the FS and consisted of 5 LNs of isolated tumor cells, 15 of micrometastasis, and 62 of macrometastasis. TIC identified metastases in 69 of these 82 SLNs (sensitivity: 84.1%, specificity: 100%, and accuracy: 97.4%). All macrometastases could be detected by TIC, whereas TIC identified approximately 50% of micrometastases and none of isolated tumor cells. The size detection limit of metastatic foci, defined as the smallest dimension of metastasis detected without false negatives, was 2 mm. The smallest metastatic focus identified was 0.8 mm.Conclusions:TIC of SLNs is of great use given its negative predictive value of 100% for identification of macrometastasis in our study. For intraoperative evaluation of SLNs, based on our data, a practical two-step approach is proposed: SLN evaluation should be initially performed by TIC and then proceed to FS histological analysis only when cytologically positive to determine the size of metastatic focus.

Current status of cytopathology practices in Korea: annual report on the Continuous Quality Improvement program of the Korean Society for Cytopathology for 2018.

BackgroundThe Korean Society for Cytopathology has conducted the Continuous Quality Improvement program for cytopathology laboratories in Korea since 1995. In 2018 as part of the program, an annual survey of cytologic data was administered to determine the current status of cytopathology practices in Korea. MethodsA questionnaire was administered to 211 cytopathology laboratories. Individual laboratories submitted their annual statistics regarding cytopathology practices, diagnoses of gynecologic samples, inadequacy rates, and gynecologic cytology-histology correlation review (CHCR) data for 2018. In addition, proficiency tests and sample adequacy assessments were conducted using five consequent gynecologic slides. ResultsOver 10 million cytologic exams were performed in 2018, and this number has almost tripled since this survey was first conducted in 2004 (compounded annual growth rate of 7.2%). The number of non-gynecologic samples has increased gradually over time and comprised 24% of all exams. The overall unsatisfactory rate was 0.14%. The ratio of the cases with atypical squamous cells to squamous intraepithelial lesions accounted for up to 4.24. The major discrepancy rate of the CHCR in gynecologic samples was 0.52%. In the proficiency test, the major discrepancy rate was approximately 1%. In the sample adequacy assessment, a discrepancy was observed in 0.1% of cases. ConclusionsThis study represents the current status of cytopathology practices in Korea, illustrating the importance of the Continuous Quality Improvement program for increasing the accuracy and credibility of cytopathologic exams as well as developing national cancer exam guidelines and government projects on the prevention and treatment of cancer.