The current state of digital cytology and artificial intelligence (AI): global survey results from the American Society of Cytopathology Digital Cytology Task Force.

INTRODUCTION: The integration of whole slide imaging (WSI) and artificial intelligence (AI) with digital cytology has been growing gradually. Therefore, there is a need to evaluate the current state of digital cytology. This study aimed to determine the current landscape of digital cytology via a survey conducted as part of the American Society of Cytopathology (ASC) Digital Cytology White Paper Task Force. MATERIALS AND METHODS: A survey with 43 questions pertaining to the current practices and experiences of WSI and AI in both surgical pathology and cytology was created. The survey was sent to members of the ASC, the International Academy of Cytology (IAC), and the Papanicolaou Society of Cytopathology (PSC). Responses were recorded and analyzed. RESULTS: In total, 327 individuals participated in the survey, spanning a diverse array of practice settings, roles, and experiences around the globe. The majority of responses indicated there was routine scanning of surgical pathology slides (n = 134; 61%) with fewer respondents scanning cytology slides (n = 150; 46%). The primary challenge for surgical WSI is the need for faster scanning and cost minimization, whereas image quality is the top issue for cytology WSI. AI tools are not widely utilized, with only 16% of participants using AI for surgical pathology samples and 13% for cytology practice. CONCLUSIONS: Utilization of digital pathology is limited in cytology laboratories as compared to surgical pathology. However, as more laboratories are willing to implement digital cytology in the near future, the establishment of practical clinical guidelines is needed.

Digital cytology part 1: digital cytology implementation for practice: a concept paper with review and recommendations from the American Society of Cytopathology Digital Cytology Task Force.

Digital cytology and artificial intelligence (AI) are gaining greater adoption in the cytopathology laboratory. However, peer-reviewed real-world data and literature are lacking regarding the current clinical landscape. The American Society of Cytopathology in conjunction with the International Academy of Cytology and the Digital Pathology Association established a special task force comprising 20 members with expertise and/or interest in digital cytology. The aim of the group was to investigate the feasibility of incorporating digital cytology, specifically cytology whole slide scanning and AI applications, into the workflow of the laboratory. In turn, the impact on cytopathologists, cytologists (cytotechnologists), and cytology departments were also assessed. The task force reviewed existing literature on digital cytology, conducted a worldwide survey, and held a virtual roundtable discussion on digital cytology and AI with multiple industry corporate representatives. This white paper, presented in 2 parts, summarizes the current state of digital cytology and AI practice in global cytology practice. Part 1 of the white paper presented herein is a review and offers best practice recommendations for incorporating digital cytology into practice. Part 2 of the white paper provides a comprehensive review of AI in cytology practice along with best practice recommendations and legal considerations. Additionally, the results of a global survey regarding digital cytology are highlighted.

Digital cytology part 2: artificial intelligence in cytology: a concept paper with review and recommendations from the American Society of Cytopathology Digital Cytology Task Force.

Digital cytology and artificial intelligence (AI) are gaining greater adoption in the cytology laboratory. However, peer-reviewed real-world data and literature are lacking in regard to the current clinical landscape. The American Society of Cytopathology in conjunction with the International Academy of Cytology and the Digital Pathology Association established a special task force comprising 20 members with expertise and/or interest in digital cytology. The aim of the group was to investigate the feasibility of incorporating digital cytology, specifically cytology whole slide scanning and AI applications, into the workflow of the laboratory. In turn, the impact on cytopathologists, cytologists (cytotechnologists), and cytology departments were also assessed. The task force reviewed existing literature on digital cytology, conducted a worldwide survey, and held a virtual roundtable discussion on digital cytology and AI with multiple industry corporate representatives. This white paper, presented in 2 parts, summarizes the current state of digital cytology and AI practice in global cytology practice. Part 1 of the white paper is presented as a separate paper which details a review and best practice recommendations for incorporating digital cytology into practice. Part 2 of the white paper presented here provides a comprehensive review of AI in cytology practice along with best practice recommendations and legal considerations. Additionally, the cytology global survey results highlighting current AI practices by various laboratories, as well as current attitudes, are reported.

Distinct profile of driver mutations and clinical features in immunomarker-defined subsets of pulmonary large-cell carcinoma.

Pulmonary large-cell carcinoma-a diagnostically and clinically controversial entity-is defined as a non-small-cell carcinoma lacking morphologic differentiation of either adenocarcinoma or squamous cell carcinoma, but suspected to represent an end stage of poor differentiation of these tumor types. Given the recent advances in immunohistochemistry to distinguish adenocarcinoma and squamous cell carcinoma, and the recent insights that several therapeutically relevant genetic alterations are distributed differentially in these tumors, we hypothesized that immunophenotyping may stratify large-cell carcinomas into subsets with distinct profiles of targetable driver mutations. We therefore analyzed 102 large-cell carcinomas by immunohistochemistry for TTF-1 and ΔNp63/p40 as classifiers for adenocarcinoma and squamous cell carcinoma, respectively, and correlated the resulting subtypes with nine therapeutically relevant genetic alterations characteristic of adenocarcinoma (EGFR, KRAS, BRAF, MAP2K1/MEK1, NRAS, ERBB2/HER2 mutations and ALK rearrangements) or more common in squamous cell carcinoma (PIK3CA and AKT1 mutations). The immunomarkers classified large-cell carcinomas as variants of adenocarcinoma (n=62; 60%), squamous cell carcinoma (n=20; 20%) or marker-null (n=20; 20%). Genetic alterations were found in 38 cases (37%), including EGFR (n=1), KRAS (n=30), BRAF (n=2), MAP2K1 (n=1), ALK (n=3) and PIK3CA (n=1). All molecular alterations characteristic of adenocarcinoma occurred in tumors with immunoprofiles of adenocarcinoma or marker-null, but not in tumors with squamous immunoprofiles (combined mutation rate 50% vs 30% vs 0%, respectively; P<0.001), whereas the sole PIK3CA mutation occurred in a tumor with squamous profile (5%). Furthermore, marker-null large-cell carcinomas were associated with significantly inferior disease-free (P<0.001) and overall (P=0.001) survival. In conclusion, the majority (80%) of large-cell carcinomas can be classified by immunomarkers as variants of adenocarcinoma or squamous cell carcinoma, which stratifies these tumors into subsets with a distinct distribution of driver mutations and distinct prognoses. These findings have practical implications for diagnosis, predictive molecular testing and therapy selection.

Comparison of multiplanar reformatted CT lung tumor measurements to axial tumor measurement alone: impact on maximal tumor dimension and T stage.

OBJECTIVE: The purpose of this study was to compare measurements of lung tumor size between axial and multiplanar reformatted CT images, as well as to establish whether the difference between these measurements leads to a change in T stage. MATERIALS AND METHODS: Patients with lung tumors who underwent chest CT up to 31 days before lung resection between December 2010 and March 2012 were included. Axial, sagittal, and coronal CT images were evaluated by two independent readers (1 and 2) who were blinded to clinical data. In 89 patients, lung tumors categorized as T1a (54%), T1b (19%), T2a (24%), or T2b (3%) were analyzed. The longest tumor diameter using multiplanar reformatted CT was compared and correlated with axial CT alone and pathologic T stage. Statistical analysis included a Wilcoxon rank sum test to evaluate differences between measurements, intraclass correlation coefficient (ICC), and kappa statistic to assess agreement. RESULTS: Prediction of T stage using axial CT alone compared with multiplanar reformatted CT agreed in 82% of patients for reader 1 (κ = 0.660 [95% CI, 0.531-0.789]) and 80% of patients for reader 2 (κ = 0.695 [95% CI, 0.572-0.818]). Prediction of T stage using multiplanar reformatted CT resulted in upstaging in 18% and 20% of patients (for readers 1 and 2, respectively). Interobserver agreement (ICC [95% CI]) was 0.900 (0.803-0.954) for axial, 0.874 (0.772-0.946) for sagittal, and 0.754 (0.556-0.921) for coronal planes. CONCLUSION: Radiologic measurement of lung tumor T stage was higher using multiplanar reformatted CT as compared with axial CT alone. When available, multiplanar reformatted CT should be used to measure tumor dimension and thus assign an accurate lung cancer T stage.

Melanotic medullary thyroid carcinoma: A case report with review of the literature.

Melanotic medullary thyroid carcinoma is morphologically defined by the presence of melanin deposits in the cytoplasm of tumor cells. It is an extremely rare variant with only 15 cases described in the literature to date and only one report of diagnosis by fine needle aspiration (FNA) biopsy. A 51-year-old woman presented with neck swelling. An ultrasound examination revealed a single solid nodule in the right thyroid lobe that measured 5.4 × 4.7 × 4.3 cm. Laboratory examination revealed elevated levels of serum calcitonin (8643.0 pg/ml), carcinoembryonic antigen (CEA) (86.2 ng/ml), and chromogranin A (123.2 ng/ml). An FNA biopsy of the thyroid nodule revealed predominantly single plasmacytoid cells with round to oval eccentric nuclei and dark brown intracytoplasmic granules. Immunohistochemical studies with Melan-A performed on a cell block slide confirmed that the granules contained melanin. The tumor cells were also positive for calcitonin, CEA, synaptophysin, AE1/AE3, CAM5.2, and HMB-45(focal); the tumor cells were negative for chromogranin, thyroglobulin, PAX8 and TTF-1. The diagnosis was reported as melanotic variant of medullary thyroid carcinoma. The patient underwent a total thyroidectomy which revealed tumor cell expression of insulinoma-associated protein 1 and confirmed neuroendocrine differentiation. Shortly after she presented with tumor recurrence in the thyroidectomy bed. The tumor cells were positive for only S100, SOX10, and Melan-A. Molecular analysis with the SEMA4 Solid Tumor Panel revealed mutations in the HRAS, PIK3CA, PIK3R1, MYC, and CCND3 genes. The final diagnosis was reported as melanocytic medullary thyroid carcinoma with high grade transformation and loss of epithelial and neuroendocrine expression.

The World Health Organization Reporting System for Lung Cytopathology.

The International Academy of Cytology has joined with the International Agency for Research on Cancer (IARC) to bring together a group of experts in lung cytopathology to develop a WHO Reporting System for Lung Cytopathology (WHO System). This WHO System defines five categories for reporting lung cytopathology, that is, "Insufficient"/"Inadequate"/"Non-diagnostic," "Benign," "Atypical," "Suspicious for malignancy," and "Malignant," each with a clear descriptive term for the category, a definition, a risk of malignancy and a suggested management algorithm. The key diagnostic cytopathology features of each of the lesions within each category have been established by consensus and will be presented more fully in a subsequent IARC e-book and published hard cover book.The WHO System provides the best practice application of ancillary testing, including immunocytochemistry and molecular pathology, and provides a review to guide sampling and processing techniques to optimize the handling and preparation of the cytopathology sample emphasizing the cytomorphological differential diagnosis to aid low-resourced settings. The authors recognize that local medical and pathology resources will vary, particularly in low- and middle-income countries, and have developed the WHO System to make it applicable worldwide based on cytomorphology with options for further diagnostic management of the patient.The online WHO System provides a direct link to the WHO Tumour Classification for Thoracic Tumours 5th Edition. It will raise the profile and use of cytopathology by increasing awareness of its current role and its potential role in the era of personalized medicine based on molecular pathology utilizing "small biopsies." Ultimately, the System will improve patient care and outcomes.This System aims to improve and standardize the reporting of cytopathology, facilitate communication between cytopathologists and clinicians and improve patient care. The System is based on the current role of lung cytopathology and synthesizes the existing evidence while highlighting areas requiring further research and the future potential role of lung cytopathology.

A comparative study of the genotype profiles of high-risk human papillomavirus infection in male and female HIV-positive patients and their correlation with anal cytology and biopsy.

INTRODUCTION: Although anal cancer is more common in women, most of the studies on the role of high-risk human papillomavirus (hrHPV) infection in anal squamous lesions have focused on high-risk male patients. Therefore, we compared the genotype profile and clinicopathologic correlation of hrHPV infection in human immunodeficiency virus-positive (HIV+) men and women. MATERIALS AND METHODS: We retrospectively analyzed 2254 HIV+ patients (1931 men and 323 women) who had undergone anal Papanicolaou tests at our institution; 1189 of them also had follow-up biopsy data available. HPV genotyping was performed using the Roche Cobas system and correlated with the cytologic and histologic diagnosis. RESULTS: Compared with the HIV+ men, the HIV+ women had a significantly lower rate of hrHPV infection (67.5% versus 78.5%; P < 0.0001) but a significantly higher rate of high-grade squamous intraepithelial lesions (HSILs) on anal Papanicolaou tests (4.6% versus 2.5%; P < 0.05). Other high-risk HPV (ohrHPV), as a group, is much more common than HPV16 or HPV18 in both genders. HIV+ women had significantly lower HPV16 and ohrHPV infection rates than did HIV+ men. However, the HPV18 infection rates were similar between HIV+ women and HIV+ men. For both genders, the rates of HSILs or high-grade anal intraepithelial neoplasia (AIN2-3) were significantly increased when coinfection of ohrHPV with either HPV16 or HPV18 was present. CONCLUSIONS: Although both HIV+ men and HIV+ women have an increased risk of hrHPV infection, HIV+ women have different hrHPV genotype profiles and higher rates of high-grade lesions. Coinfection with different genotypes of hrHPV can significantly increase the risk of HSILs or AIN2-3 in both genders and could requires vigilant clinical and laboratory follow-up.

Core needle lung biopsy specimens: adequacy for EGFR and KRAS mutational analysis.

OBJECTIVE: The purpose of this study was to prospectively compare the adequacy of core needle biopsy specimens with the adequacy of specimens from resected tissue, the histologic reference standard, for mutational analysis of malignant tumors of the lung. SUBJECTS AND METHODS: The first 18 patients enrolled in a phase 2 study of gefitinib for lung cancer in July 2004 through August 2005 underwent CT- or fluoroscopy-guided lung biopsy before the start of gefitinib therapy. Three weeks after gefitinib therapy, the patients underwent lung tumor resection. The results of EGFR and KRAS mutational analysis of the core needle biopsy specimens were compared with those of EGFR and KRAS mutational analysis of the surgical specimens. RESULTS: Two specimens were unsatisfactory for mutational analysis. The results of mutational assay results of the other 16 specimens were the same as those of analysis of the surgical specimens obtained an average of 31 days after biopsy. CONCLUSION: Biopsy with small (18- to 20-gauge) core needles can yield sufficient and reliable samples for mutational analysis. This technique is likely to become an important tool with the increasing use of pharmacotherapy based on the genetics of specific tumors in individual patients.

Building a smart FNA cart: When Google meets cytology.

BACKGROUND: The appropriate management of a fine needle aspiration (FNA) supply cart and equipment set up is essential to ensure the smooth and optimal operation of a busy FNA clinic. We applied Lean strategies such as value stream mapping (VSM), the 5S method (Sort, Set in order, Shine, Standardize, Sustain), and Kanban to remove waste and improve patient flow in an FNA clinic. METHODS: The workflow analysis suggested that existent problems such as suboptimal inventory management and unavailability of standard operating procedures (SOPs) caused a 10% to 85% increase in total procedure time. To improve inventory management, we created a 2-bin Kanban system. We used the "Scan to Web" app and a Google Drive form to create a cost-effective electronic inventory management system. We distributed the essential SOPs in the format of video clips using our YouTube channel and leveraged barcode technology to access the links. RESULTS: Upon completion of our process improvement project, we succeeded to eliminate the stock-out events and maintain a process cycle efficiency of 87%. The 5S audit checklist result increased from 6% to 100% implementation, which is consistent with focused improvement. The developed inventory system enabled us to track the supply usage, forecast demands, and improve the accuracy of orders. CONCLUSIONS: Lean methods such as VSM, 5S, and Kanban combined with open source technologies can be implemented to ensure material availability, track inventory, and provide immediate access to SOPs on demand. The developed system also led to increased efficiency and improved flow, as well as responsiveness to changes in demand.

EGFR mutations in lung adenocarcinomas: clinical testing experience and relationship to EGFR gene copy number and immunohistochemical expression.

Lung adenocarcinomas responsive to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors possess EGFR mutations and often increased EGFR copy number. We prospectively studied 334 clinical cases using polymerase chain reaction-based assays to detect deletions within exon 19 and the L858R mutation in exon 21, which together account for approximately 90% of EGFR mutations. Seventy-eight (23%) of these tumors had an EGFR mutation, with 55 (71%) exon 19 deletions and 23 (29%) exon 21 L858R mutations. We were able to compare mutant and normal EGFR alleles and found a preferential amplification of the mutant allele. The association of mutations with EGFR amplification (determined by chromogenic in situ hybridization) and EGFR expression (determined by immunohistochemistry) was further examined in a subset of 60 tumors. EGFR amplification (> or =5 EGFR signals per nucleus) was seen in 15 of 29 (52%) EGFR-mutated tumors but in only five of 31 (6%) non-mutated tumors (P = 0.006). EGFR overexpression was strongly associated with amplification but was statistically independent of EGFR mutation. Most patients with EGFR mutations (17 of 29, 59%) never smoked compared with 13% (four of 31) of patients lacking such mutations (P = 0.0003). The association of amplification with smoking status was marginal and was nonexistent with EGFR expression. Thus, these results indicate that EGFR amplification, preferentially of the mutant allele, often accompanies EGFR mutation, whereas EGFR immunohistochemical staining associates with amplification but cannot predict EGFR mutation status.

Global gene expression profiling of pleural mesotheliomas: overexpression of aurora kinases and P16/CDKN2A deletion as prognostic factors and critical evaluation of microarray-based prognostic prediction.

Most gene expression profiling studies of mesothelioma have been based on relatively small sample numbers, limiting their statistical power. We did Affymetrix U133A microarray analysis on 99 pleural mesotheliomas, in which multivariate analysis showed advanced-stage, sarcomatous histology and P16/CDKN2A homozygous deletion to be significant independent adverse prognostic factors. Comparison of the expression profiles of epithelioid versus sarcomatous mesotheliomas identified many genes significantly overexpressed among the former, including previously unrecognized ones, such as uroplakins and kallikrein 11, both confirmed by immunohistochemistry. Examination of the gene expression correlates of survival showed that more aggressive mesotheliomas expressed higher levels of Aurora kinases A and B and functionally related genes involved in mitosis and cell cycle control. Independent confirmation of the negative effect of Aurora kinase B was obtained by immunohistochemistry in a separate patient cohort. A role for Aurora kinases in the aggressive behavior of mesotheliomas is of potential clinical interest because of the recent development of small-molecule inhibitors. We then used our data to develop microarray-based predictors of 1 year survival; these achieved a maximal accuracy of 68% in cross-validation. However, this was inferior to prognostic prediction based on standard clinicopathologic variables and P16/CDNK2A status (accuracy, 73%), and adding the microarray model to the latter did not improve overall accuracy. Finally, we evaluated three recently published microarray-based outcome prediction models, but their accuracies ranged from 63% to 67%, consistently lower than reported. Gene expression profiling of mesotheliomas is an important discovery tool, but its power in clinical prognostication has been overestimated.

Pulmonary toxicity associated with erlotinib.

Interstitial lung disease (ILD) related to therapy with the drug gefitinib has been well reported. The adverse pulmonary effects of erlotinib are less well known. We report a case of fatal pulmonary toxicity in a patient with advanced non-small cell lung cancer who received erlotinib. He had been found to have pathologic findings of usual interstitial pneumonia (UIP) on the resected lung cancer specimen prior to receiving erlotinib. This case and other published evidence should alert physicians to the possibility of fatal erlotinib-induced ILD. Similar to reports in patients receiving gefitinib, those with pathologic findings of UIP on resected lung specimens or known pulmonary fibrosis may be at particular risk for erlotinib pulmonary toxicity.

Clinical course of patients with non-small cell lung cancer and epidermal growth factor receptor exon 19 and exon 21 mutations treated with gefitinib or erlotinib.

PURPOSE: In patients with non-small cell lung cancer (NSCLC), mutations in the epidermal growth factor receptor (EGFR) tyrosine kinase domain have been associated with sensitivity to erlotinib and gefitinib. We undertook this study to explore the relationship between EGFR mutation type and clinical variables, including treatment with gefitinib and erlotinib. EXPERIMENTAL DESIGN: In patients with NSCLC, EGFR exon 19 deletion mutations and EGFR L858R point mutations were analyzed by nonsequencing PCR-based methods from paraffin blocks of tissue obtained before treatment. The results were correlated with clinical information (sex, pathologic subtype, race/ethnicity, treatment, and overall survival). RESULTS: The two most common EGFR mutations were identified in 24% (70 of 291; 95% confidence interval, 26%-38%) of tumors from patients with NSCLC. EGFR mutation was associated with Asian ethnicity (P = 0.0023) and being a "never smoker" (P = 0.0001). Among patients with EGFR mutations, 39% (27 of 70) had EGFR L858R, whereas 61% (43 of 70) had an EGFR exon 19 deletion. After treatment with erlotinib (n = 12) or gefitinib (n = 22), patients with EGFR mutations had a median overall survival of 20 months. After treatment with erlotinib or gefitinib, patients with EGFR exon 19 deletions had significantly longer median survival than patients with EGFR L858R (34 versus 8 months; log-rank P = 0.01). CONCLUSIONS: EGFR mutations in exons 19 or 21 are correlated with clinical factors predictive of response to gefitinib and erlotinib. Those with EGFR exon 19 deletion mutations had a longer median survival than patients with EGFR L858R point mutation. These observations warrant confirmation in a prospective study and exploration of the biological mechanisms of the differences between the two major EGFR mutations.

Novel D761Y and common secondary T790M mutations in epidermal growth factor receptor-mutant lung adenocarcinomas with acquired resistance to kinase inhibitors.

PURPOSE: In patients whose lung adenocarcinomas harbor epidermal growth factor receptor (EGFR) tyrosine kinase domain mutations, acquired resistance to the tyrosine kinase inhibitors (TKI) gefitinib (Iressa) and erlotinib (Tarceva) has been associated with a second-site EGFR mutation, which leads to substitution of methionine for threonine at position 790 (T790M). We aimed to elucidate the frequency and nature of secondary EGFR mutations in patients with acquired resistance to TKI monotherapy. EXPERIMENTAL DESIGN: Tumor cells from patients with acquired resistance were examined for secondary EGFR kinase domain mutations by molecular analyses. RESULTS: Eight of 16 patients (50% observed rate; 95% confidence interval, 25-75%) had tumor cells with second-site EGFR mutations. Seven mutations were T790M and one was a novel D761Y mutation found in a brain metastasis. When combined with a drug-sensitive L858R mutation, the D761Y mutation modestly reduced the sensitivity of mutant EGFR to TKIs in both surrogate kinase and cell viability assays. In an autopsy case, the T790M mutation was found in multiple visceral metastases but not in a brain lesion. CONCLUSIONS: The T790M mutation is common in patients with acquired resistance. The limited spectrum of TKI-resistant mutations in EGFR, which binds to erlotinib in the active conformation, contrasts with a wider range of second-site mutations seen with acquired resistance to imatinib, which binds to ABL and KIT, respectively, in closed conformations. Collectively, our data suggest that the type and nature of kinase inhibitor resistance mutations may be influenced by both anatomic site and mode of binding to the kinase target.

Analytic inquiry: Molecular testing in lung cancer.

Non-small cell lung cancer is a different disease from what it was a decade ago. The last 10 years were based on remarkable advances in the understanding of key genetic alterations that function as oncogenic drivers and serve as therapeutic targets, thereby defining new molecular subsets. These changes have had an impact on clinical care, patient outcomes, and pathologic diagnosis and present new challenges in the approach of the cytopathologist to this still deadly disease. To meet these new challenges and appropriately train the next generation of cytopathologists, the complex molecular background underlying this disease and the implications that cytologic and histologic diagnoses have on treatment must be understood. Herein, the author reviews the background leading to this new approach and explains how, why, and what cytologists need to know to successfully contribute to the care of the patient with lung cancer. Cancer Cytopathol 2017;125(6 suppl):470-6. © 2017 American Cancer Society.

Cytopathologic analysis of thyroid lesions in the pediatric population.

Fine-needle aspiration (FNA) of the thyroid is seldom performed in the pediatric population. Therefore, the clinical utility of thyroid FNA in this patient group has not been adequately addressed. A 15 yr retrospective review of the cytopathology archives at the participating institutions was performed to identify cases of thyroid FNA performed in pediatric patients. The medical records of these cases were reviewed, including the surgical pathology reports of those patients who had subsequently undergone surgical resection. One hundred one specimens from 82 patients were identified. Of these, 40 had a cytopathologic diagnosis of carcinoma, "suspicious" for carcinoma, neoplasm, or atypia, 48 were benign, and 13 were unsatisfactory. Of the 82 patients, 45 underwent partial or total thyroidectomy. Twenty-two (49%) of these were found to harbor a malignant neoplasm (18 papillary carcinomas). The diagnostic sensitivity for identifying a lesion was 87% (26/30) and the diagnostic specificity was 92% (47/51). There were four false-positives and four false-negatives in the review, yielding a positive predictive value of 87% and a negative predictive value of 92%. We conclude that FNA is a useful adjunct to the management of thyroid lesions in the pediatric population, with good diagnostic accuracy. Although thyroid neoplasms are relatively rare in children, our experience demonstrated that 40% of thyroid masses referred for FNA had an interpretation that caused concern, ranging from "atypical" to carcinoma. Additionally, a benign diagnosis by FNA may avoid unnecessary surgery with its potential complications, a significant consideration for this age group.

Morphologic Accuracy in Differentiating Primary Lung Adenocarcinoma From Squamous Cell Carcinoma in Cytology Specimens.

CONTEXT: -The National Cancer Care Network and the combined College of American Pathologists/International Association for the Study of Lung Cancer/Association for Molecular Pathology guidelines indicate that all lung adenocarcinomas (ADCs) should be tested for epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements. As the majority of patients present at a later stage, the subclassification and molecular analysis must be done on cytologic material. OBJECTIVE: -To evaluate the accuracy and interobserver variability among cytopathologists in subtyping non-small cell lung carcinoma using cytologic preparations. DESIGN: -Nine cytopathologists from different institutions submitted cases of non-small cell lung carcinoma with surgical follow-up. Cases were independently, blindly reviewed by each cytopathologist. A diagnosis of ADC or squamous cell carcinoma was rendered based on the Diff-Quik, Papanicolaou, and hematoxylin-eosin stains. The specimen types included fine-needle aspiration from lung, lymph node, and bone; touch preparations from lung core biopsies; bronchial washings; and bronchial brushes. A major disagreement was defined as a case being misclassified 3 or more times. RESULTS: -Ninety-three cases (69 ADC, 24 squamous cell carcinoma) were examined. Of 818 chances (93 cases × 9 cytopathologists) to correctly identify all the cases, 753 correct diagnoses were made (92% overall accuracy). Twenty-five of 69 cases of ADC (36%) and 7 of 24 cases of squamous cell carcinoma (29%) had disagreement (P = .16). Touch preparations were more frequently misdiagnosed compared with other specimens. Diagnostic accuracy of each cytopathologist varied from 78.4% to 98.7% (mean, 91.7%). CONCLUSION: -Lung ADC can accurately be distinguished from squamous cell carcinoma by morphology in cytologic specimens with excellent interobserver concordance across multiple institutions and levels of cytology experience.

KRAS mutations and primary resistance of lung adenocarcinomas to gefitinib or erlotinib.

BACKGROUND: Somatic mutations in the gene for the epidermal growth factor receptor (EGFR) are found in adenocarcinomas of the lung and are associated with sensitivity to the kinase inhibitors gefitinib (Iressa) and erlotinib (Tarceva). Lung adenocarcinomas also harbor activating mutations in the downstream GTPase, KRAS, and mutations in EGFR and KRAS appear to be mutually exclusive. METHODS AND FINDINGS: We sought to determine whether mutations in KRAS could be used to further enhance prediction of response to gefitinib or erlotinib. We screened 60 lung adenocarcinomas defined as sensitive or refractory to gefitinib or erlotinib for mutations in EGFR and KRAS. We show that mutations in KRAS are associated with a lack of sensitivity to either drug. CONCLUSION: Our results suggest that treatment decisions regarding use of these kinase inhibitors might be improved by determining the mutational status of both EGFR and KRAS.