Subtyping of non-small cell lung carcinoma: a comparison of small biopsy and cytology specimens

One procedure-one report: the Re-Imagine Cytopathology Task Force position paper on small tissue biopsy triage in anatomic pathology

INTRODUCTION

Endoscopic biopsy procedures increasingly generate multiple tissue samples from multiple sites, and frequently retrieve concurrent cytologic specimens and small core needle biopsies. There is currently lack of consensus in subspecialized practices as to whether cytopathologists or surgical pathologists should review such samples, and whether the pathology findings should be reported together or separately.

MATERIALS AND METHODS

In December 2021, the American Society of Cytopathology convened the Re-Imagine Cytopathology Task Force to examine various workflows that would facilitate unified pathology reporting of concurrently obtained biopsies and improve clinical care.

RESULTS AND CONCLUSIONS

This position paper summarizes the key points and highlights the advantages, challenges, and resources available to support the implementation of such workflows that result in "one procedure-one report".

Non-small cell lung carcinoma subtyping in conventional cytology: Results of the IASLC Cytology Working Group survey to determine specific cytomorphological criteria for adenocarcinoma and squamous cell carcinoma

INTRODUCTION

Accurate subtyping of non-small cell lung carcinomas (NSCLC) into lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) is the cornerstone of NSCLC diagnosis. Cytology samples show higher rates of classification failures, i.e., subtyping as non-small cell carcinoma, not otherwise specified (NSCC-NOS), as compared to histology. This study aims to identify specific algorithms based on known cytomorphological features that aid accurate and successful subtyping of NSCLC on cytology.

METHODS

Thirteen expert cytopathologists participated anonymously in an online survey to subtype 119 NSCLC cytology cases (gold standard diagnoses being LUAD in 80 and LUSC in 39) enriched for non-keratinising LUSC. They selected from 23 pre-defined cytomorphological features that they used in subtyping. Data were analysed using machine learning algorithms based on Random Forest Method and regression trees.

RESULTS

From 1474 responses recorded, concordant cytology typing was achieved in 53.7% (792/1474) responses. NSCC-NOS rates on cytology were similar among gold standard LUAD (36%) and LUSC (38%) cases. Misclassification rates were higher in gold standard LUSC (17.6%) than gold standard LUAD (5.5%; P<0.0001). Keratinisation, when present, recognised LUSC with high accuracy. In its absence, the ML algorithms developed based on experts' choices were unable to reduce cytology NSCC-NOS rates without increasing misclassification rates.

CONCLUSION

Suboptimal recognition of LUSC in the absence of keratinisation remains the major hurdle in improving cytology subtyping accuracy with such cases either failing classification (NSCC-NOS) or misclassifying as LUAD. NSCC-NOS appears to be an inevitable morphological diagnosis emphasizing that ancillary IC is necessary to achieve accurate subtyping on cytology.

Correlation between cytological and histopathological diagnosis of non-small cell lung cancer and accuracy of cytology in the diagnosis of lung cancer

Background/Aim. Lung cancer is one of the most com-mon cancer types worldwide. More than 70% of patients are diagnosed with lung cancer in the advanced stages of the disease, with limited therapeutic options based on cytological and histopathological material. The value of cytology in diagnosing and subtyping non-small cell lung cancer (NSCLC) is very important for modern personalized therapies. The aim of this study was to find out the concordance between cytological and histopathological diagnosis of NSCLC and the accuracy, sensitivity, specificity, and the positive and negative predictive value of cytology in diagnosing lung cancer. Methods. A two-year retrospective study included 169 patients with cytological diagnosis of NSCLC, who, at the same time, had small biopsy and surgical specimens for histopathological diagnoses confirmation that were compared with cytological one. Histopathological diagnosis on surgical specimens was the golden standard for evaluation concordance to the cytological diagnosis of NSCLC and evaluation accuracy, specificity, sensitivity, and the positive and negative prognostic value of cytology as a diagnostic method for detecting lung cancer. Results. This study included 129 (76.3%) male and 40 (23.7%) female patients, aged between 39 and 83, with the average of 62.53 ? 7.6. There was no statistically significant difference between the ages of different genders (p = 0.207). The most frequent diagnosis among cytological diagnoses was NSCLC in 99 (58.58%) patients. Concordance between cytological and histopathological diagnoses of surgical specimens was 61.48%. There was no statistically significant difference between cytological diagnoses and histopathological diagnoses of small biopsies specimens (p = 0.856). The sensitivity, specificity, positive and negative prognostic value, and accuracy of cytology as a diagnostic method of lung cancer were 94.98%, 98.60%, 95.72%, 98.35%, and 97.71%, respectively. Conclusion. Cytological diagnosis of NSCLC is accurate, with high sensitivity, specificity, and benefits for patients. Most patients are diagnosed with advanced cancer when there is no surgical therapy option, and the only available diagnostic material is a small biopsy sampled during bronchoscopy.

3D-PulCNN: Pulmonary cancer classification from hyperspectral images using convolution combination unit based CNN

Pulmonary cancer is one of the most common malignancies worldwide. Accurate classification of its subtypes is required in differential diagnosis. However, existing algorithms are mostly based on color images, and the improvement of accuracy is quite challenging. In this study, we propose a convolution combination unit (CCU)-based three-dimensional convolutional neural network (3D-PulCNN) for classifying pulmonary cancer presented in microscopic hyperspectral image with both spatial and spectral information. CCU is designed to fuse the features acquired by different convolution scales. Compared with VGGNet, only two fully connected layers are used in this model, reducing the network parameters and model complexity. Experimental results show that 3D-PulCNN achieves overall average (OA) of 0.962 and Precision, Recall, and Kappa of more than 0.920, superior to 2D-VGGNet. Then, 3D-UNet is leveraged to segment cancer cells, and their morphological characteristics are calculated to supply quantitative virtual analysis data for classification results explanation and prognosis assessment.

Can cytology reliably subtype non-small cell lung carcinomas?

Cytology specimens play an important role in the diagnosis and predictive testing of lung cancer. While morphological characterisation of small cell and non-small cell lung carcinomas (NSCLC) on cytology is possible, further subtyping of NSCLC into adenocarcinoma and squamous cell carcinoma morphology is also mandatory in the current era of personalised medicine. Notably, cytology specimens in different forms (fine needle aspiration, exfoliative, and cell block) with or without immunocytochemistry are reliable sources for accurate diagnosis of adenocarcinoma and squamous cell carcinoma as evidenced by numerous studies present in the literature. However, there are instances where subtyping of NSCLC based on morphology alone is challenging on cytology samples, especially non-cell block preparations. In this paper, we will discuss current concepts, advances, and challenges of subtyping NSCLC in cytology specimens.

Molecular cytology of the respiratory tract and pleura

There is growing evidence that molecular testing is feasible on all types of cytological preparation, which is fortunate as more diagnostic markers and biomarkers for targeted therapies are discovered for use in pulmonary and pleural malignancies. In this article we will discuss the pre-analytic, analytic, and post-analytic (interpretive) considerations for successful implementation of molecular tests for diagnostic and predictive markers in respiratory and pleural cytology. The vast majority of laboratories are familiar with, and have validated their molecular protocols for, formalin-fixed paraffin-embedded surgical specimens, which are not directly applicable to cytology specimens. Thus, rigorous validation must be performed for each type of fixative and cytology preparation before it is implemented in the clinical setting.

Advances in cytology of lung cancer

Cytopathology has emerged as a promising platform in precision oncology especially after the revolutionary change in our understanding of the concept of lung cancer etiopathogenesis. With increasing use of minimally invasive techniques for sample acquisition, it becomes almost mandatory to utilize precious cytology samples maximally and judiciously by appropriate triaging of the specimen and timely action of the cytopathology team. Existing patient management protocols require accurate morphologic and molecular diagnosis of the lung cancer specimens which needs knowledge about evolving techniques related to specimen procurement, updates of genomic variants of lung cancer and recently developed molecular testing platforms and algorithms which are capable enough to use even miniscule amount of diagnostic material. This review provides a brief knowledge about advances in cytology of lung cancer which are helpful for developing correct clinical management strategies.

Utility of liquid-based cytology on residual needle rinses collected from core needle biopsy for lung nodule diagnosis

BACKGROUND

Core needle biopsy (CNB) has become the most common tissue sampling modality for pathological diagnosis of peripheral lung nodules. However, approximately 10% of pulmonary CNB specimens cannot be unambiguously diagnosed, even with auxiliary techniques. This retrospective study investigated the diagnostic value of liquid-based cytology on residual pulmonary CNB material collected from needle rinses.

METHODS

Computed tomography-guided pulmonary CNB specimens and relevant cytology of CNB needle rinses (CNR) from July 2017 to June 2020 were reviewed. A total of 406 patients, each of whom underwent a CNB procedure, were included in the study.

RESULTS

Of the 406 cases, a more serious diagnosis was rendered by CNR in 6.4% (n = 26) of cases. Furthermore, among these 26 cases, 13 malignancies were confirmed only from CNR. Of the remaining 13 patients with uncertain lesions identified from CNR, six were diagnosed with definite benign lesions from tissue samples, five were found to harbor malignant neoplasms through repeated CNB or follow-up examination, and two had tuberculosis. The sensitivity (320/332, 96.4%) of combined CNR/CNB (both CNR and CNB) in distinguishing malignancies from benign lesions was higher than that of CNB alone (307/332, 92.5%). A total of 320 malignant neoplasms included 198 cases of primary lung adenocarcinoma and 71 cases of primary lung squamous cell carcinoma.

CONCLUSIONS

CNR with higher nuclear and cytoplasmic resolution than CNB exhibited a high diagnostic efficacy for differentiating malignant from benign lesions in the lung. Moreover, combined CNR/CNB achieved optimal results in reducing the false-negative rate and the subtyping of non-small cell lung cancer.

Cytology samples and molecular biomarker testing in lung cancer-advantages and challenges

This review presents an overview on molecular diagnostic in lung cancer using cytologic samples. Every patient with advanced non-small cell lung cancer (NSCLC) should be tested for targetable driver mutations and gene arrangements. If a mutation is found, this may open an option for targeted therapy. As most of the NSCLC patients in advanced stage of disease are no candidates for surgery, these tests have to be performed on small biopsies or cytology samples. The most common and treatable gene alterations should be tested in every patient: EGFR, ALK, ROS1. A growing number of other genetic changes with targetable mutations may become treatable in the near future. To find patients who might profit from inclusion into clinical studies, relevant additional markers may be tested in an appropriate context. Another important approach for treatment is immunotherapy of lung cancer, which is guided by status of PD-L1 expression on tumour cells. The use of cytology samples carries considerable advantages: often, DNA of high quality is extracted thus enabling easy and precise analysis, and samples may be easily obtained. In case of effusions, effusion fluid seldom is not aspirated for immediate patient relief, so no additional dedicated procedure is needed. Some challenges exist: If the tumour cell count is low, mutations with a low allelic frequency may be missed. In cellblocks formalin-induced DNA, damage may obviate any DNA analysis. In very cellular smears, FISH may be impossible due to massive overlapping of nuclei. Autofluorescence may impede FISH analysis. Although there is no real universal test for genomic profiling for lung cancer, the pathology laboratory must be prepared to offer different assays on different specimens in order to address turnaround time and optimise detections of difficult tumour alterations such as gene fusions. The data from the literature demonstrate that cytology show consistent results, and it is a good alternative for lung cancer molecular testing.

Diagnostic utility of fine needle aspiration cytology and core biopsy histopathology with or without immunohistochemical staining in the subtyping of the non-small cell lung carcinomas: Experience from an academic centre in Turkey

INTRODUCTION

This retrospective morphological study compared the results of fine needle aspiration (FNA) cytology, haematoxylin-eosin (HE)-stained samples and immunohistochemical (IHC)-stained core needle biopsy (CNB) histology samples for primary non-small cell lung cancer (NSCLC) subtyping. We assessed the diagnostic utility of these methods to investigate the contribution of each method to NSCLC subtyping. We also identified the point at which NSCLC subtyping could be performed using histomorphology alone without IHC.

METHODOLOGY

Concurrent FNA and CNB specimens obtained via a single computed tomography-guided procedure and diagnosed as NSCLC in the Pathology Department of our university within 3 years were reviewed. The results of FNA samples, HE-stained biopsies and IHC-stained biopsies were compared according to subtype.

RESULTS

A total of 141 subjects were enrolled in the study. For subtyping, FNA provided an accurate diagnosis in 70 (55.1%) of 127 eligible subjects after the exclusion of 14 cases determined as not otherwise specified. CNB histology without IHC achieved a diagnosis in 53 (41.7%) of 127 subjects, which was a significant difference (P < .05). The compatibility rate between HE-stained biopsy samples and IHC-stained biopsy samples was 41.7% (53/127).

CONCLUSION

The diagnosis rates achieved using FNA, HE-stained CNB samples and IHC-stained CNB samples were 54.6% (77/141), 37.6% (53/141) and 90.1% (127/141), respectively. The subtype was identified in 55.1% of the subjects evaluated using FNA and 41.7% of subjects assessed using HE-stained biopsy samples without IHC. FNA provided a better result for squamous cell carcinoma than adenocarcinoma (55.1% vs 47.6%), but the diagnosing of adenocarcinoma and squamous cell carcinoma using HE-stained biopsy samples was similar (42% vs 41.7%).

Insulinoma-associated Protein 1 (INSM1) Is a Better Marker for the Diagnosis and Prognosis Estimation of Small Cell Lung Carcinoma Than Neuroendocrine Phenotype Markers Such as Chromogranin A, Synaptophysin, and CD56

To diagnose small cell lung carcinoma (SCLC), neuroendocrine (NE) phenotype markers such as chromogranin A, synaptophysin, and CD56 are helpful. However, because they are dispensable, SCLCs occur without apparent NE phenotypes. Insulinoma-associated protein 1 (INSM1) is a transcription factor for NE differentiation and has emerged as a single practical marker for SCLC. Using the surgical samples of 141 pulmonary NE tumors (78 SCLCs, 44 large cell NE carcinomas, and 19 carcinoids), and 246 non-NE carcinomas, we examined the immunohistochemical expression and prognostic relevance of INSM1 in association with NE phenotype markers. We evaluated its sensitivity and specificity for SCLC diagnosis, as well as its usefulness to diagnose SCLC without NE marker expression and to estimate the prognosis. INSM1 was expressed in SCLCs (92%, 72/78), large cell NE carcinomas (68%, 30/44), and carcinoids (95%, 18/19). In addition, among SCLCs with no expression of NE phenotype markers (n=12), 9 (75%) were positive for INSM1. These data suggest the superiority of INSM1 to the phenotype markers. Only 7% of adenocarcinomas (9/134) and 4% of squamous cell carcinomas (4/112) were positive for INSM1. SCLC with low-INSM1 expression (n=28) had a significantly better prognosis (P=0.040) than the high-INSM1 group (n=50). Our study revealed that INSM1 is highly sensitive and specific to detect SCLC and can estimate prognosis. INSM1 will be a promising marker for SCLC.

Diagnostic patterns of non-small-cell lung cancer at Princess Margaret Cancer Centre

Background

Accurate classification of lung cancer subtypes has become critical in tailoring lung cancer treatment. Our study aimed to evaluate changes in diagnostic testing and pathologic subtyping of advanced non-small-cell lung cancer (nsclc) over time at a major cancer centre.

Methods

In a review of patients diagnosed with advanced nsclc at Princess Margaret Cancer Centre between 2007-2009 and 2013-2015, diagnostic method, sample type and site, pathologic subtype, and use of immunohistochemistry (ihc) staining and molecular testing were abstracted.

Results

The review identified 238 patients in 2007-2009 and 283 patients in 2013-2015. Over time, the proportion of patients diagnosed with adenocarcinoma increased to 73.1% from 60.9%, and diagnoses of nsclc not otherwise specified (nos) decreased to 6.4% from 18.9%, p < 0.0001. Use of diagnostic bronchoscopy decreased (26.9% vs. 18.4%), and mediastinal sampling procedures, including endobronchial ultrasonography, increased (9.2% vs. 20.5%, p = 0.0001). Use of ihc increased over time to 76.3% from 41.6% (p < 0.0001). Larger surgical or core biopsy samples and those for which ihc was performed were more likely to undergo biomarker testing (both p < 0.01).

Conclusions

Customizing treatment based on pathologic subtype and molecular genotype has become key in treating patients with advanced lung cancer. Greater accuracy of pathology diagnosis is being achieved, including through the routine use of ihc.

Genetic Markers in Lung Cancer Diagnosis: A Review

Lung cancer is the most often diagnosed cancer in the world and the most frequent cause of cancer death. The prognosis for lung cancer is relatively poor and 75% of patients are diagnosed at its advanced stage. The currently used diagnostic tools are not sensitive enough and do not enable diagnosis at the early stage of the disease. Therefore, searching for new methods of early and accurate diagnosis of lung cancer is crucial for its effective treatment. Lung cancer is the result of multistage carcinogenesis with gradually increasing genetic and epigenetic changes. Screening for the characteristic genetic markers could enable the diagnosis of lung cancer at its early stage. The aim of this review was the summarization of both the preclinical and clinical approaches in the genetic diagnostics of lung cancer. The advancement of molecular strategies and analytic platforms makes it possible to analyze the genome changes leading to cancer development-i.e., the potential biomarkers of lung cancer. In the reviewed studies, the diagnostic values of microsatellite changes, DNA hypermethylation, and p53 and KRAS gene mutations, as well as microRNAs expression, have been analyzed as potential genetic markers. It seems that microRNAs and their expression profiles have the greatest diagnostic potential value in lung cancer diagnosis, but their quantification requires standardization.

Lung cancer cytology and small biopsy specimens: diagnosis, predictive biomarker testing, acquisition, triage, and management

In the 21st century, there has been a dramatic shift in the management of advanced-stage lung carcinoma, and this has coincided with an increasing use of minimally invasive tissue acquisition methods. Both have had significant downstream effects on cytology and small biopsy specimens. Current treatments require morphologic, immunohistochemical, and/or genotypical subtyping of non-small cell lung carcinoma. To meet these objectives, standardized classification of cytology and small specimen diagnoses, immunohistochemical algorithms, and predictive biomarker testing guidelines have been developed. This review provides an overview of current classification, biomarker testing, methods of small specimen acquisition and triage, clinical management strategies, and emerging technologies.

EGFR mutation exists in squamous cell lung carcinoma

Whether EGFR mutation occurs in lung squamous cell carcinoma (SCC) remains a controversial issue. Although numerous trials have shown positive response to tyrosine kinase inhibitors in SCC, these observations have not been well correlated with presence or absence of EGFR mutation. A complicating issue is that adenosquamous carcinoma, a mimic of SCC, frequently harbours EGFR mutations. We evaluated the EGFR mutation status of 191 cases initially diagnosed as SCC of lung origin in years 2000-2011, and performed a panel of markers including p40, p63, CK5/6, TTF-1, mucicarmine on the tissue microarray or tissue blocks from each case, to ascertain the squamous differentiation of each case. Four cases were found to have EGFR mutations, with three showing typical squamous morphological features and immunohistochemical profile on all available tumour blocks, and one reclassified as adenosquamous carcinoma. Mixed responses were noted for two of the patients with EGFR-mutated SCC treated with tyrosine kinase inhibitors. In conclusion, we report that a small subset of rigorously proven SCC harbours EGFR mutation. It also appears in our cohort that EGFR-mutated tumours, in the context of SCC, may have relatively poor response to tyrosine kinase inhibitors.

Lung Adenocarcinoma has a Higher Risk of Lymph Node Metastasis than Squamous Cell Carcinoma: A Propensity Score-Matched Analysis

BACKGROUND

Controversy still exists in which subtype of non-small-cell lung cancer [squamous cell carcinoma (SCC) or adenocarcinoma] is more likely to have lymph node (LN) metastasis. The aim of this study is to compare the pattern of LN metastasis in two cohorts of matched patients surgically treated for SCC or adenocarcinoma.

METHODS

A retrospective analysis of patients undergoing lobectomy or segmentectomy with systematic lymphadenectomy without preoperative treatment for lung SCC or adenocarcinoma was conducted in this study. Data for analysis consisted of age, gender, tumor size, lobe-specific tumor location, tumor location (peripheral or central), and pathologic findings. We conducted the propensity score-matched (PSM) analysis to eliminate potential bias effects of possible confounding factors.

RESULTS

From January 2015 to December 2016 in our department, we finally included a total of 387 patients (including 63 patients with SCC and 324 patients with adenocarcinoma) for analysis. For the unmatched cohort, there was no sufficient evidence of significantly different number of positive LNs (P = 0.90) and rate of LN metastasis (P = 0.23) between SCC patients and adenocarcinoma patients. However, potential confounding factors, for example gender, tumor size, tumor location, tumor differentiation, and total number of dissected LNs, were significantly different between patients with SCC and those with adenocarcinoma. In the analysis of matched cohort after PSM analysis, those above confounding factors were comparable between the two groups. However, patients with adenocarcinoma had significantly more mean positive LNs (2.2 and 0.7; P = 0.008) and a higher rate of LN metastasis (53% and 29%; P = 0.016) than those with SCC.

CONCLUSIONS

Lung adenocarcinoma had a higher risk of LN metastasis than SCC, suggesting that different therapeutic modalities may be indicated for the two different subtypes of lung cancer.

Immune-enrichment of non-small cell lung cancer baseline biopsies for multiplex profiling define prognostic immune checkpoint combinations for patient stratification

Background

Permanence of front-line management of lung cancer by immunotherapies requires predictive companion diagnostics identifying immune-checkpoints at baseline, challenged by the size and heterogeneity of biopsy specimens.

Methods

An innovative, tumor heterogeneity reducing, immune-enriched tissue microarray was constructed from baseline biopsies, and multiplex immunofluorescence was used to profile 25 immune-checkpoints and immune-antigens.

Results

Multiple immune-checkpoints were ranked, correlated with antigen presenting and cytotoxic effector lymphocyte activity, and were reduced with advancing disease. Immune-checkpoint combinations on TILs were associated with a marked survival advantage. Conserved combinations validated on more than 11,000 lung, breast, gastric and ovarian cancer patients demonstrate the feasibility of pan-cancer companion diagnostics.

Conclusions

In this hypothesis-generating study, deepening our understanding of immune-checkpoint biology, comprehensive protein-protein interaction and pathway mapping revealed that redundant immune-checkpoint interactors associate with positive outcomes, providing new avenues for the deciphering of molecular mechanisms behind effects of immunotherapeutic agents targeting immune-checkpoints analyzed.

Electronic supplementary material

The online version of this article (10.1186/s40425-019-0544-x) contains supplementary material, which is available to authorized users.

Role of Immunocytochemistry in the Cytological Diagnosis of Pulmonary Tumors

Pulmonary cytology is a challenging diagnostic tool, and it is usually evaluated considering medical history and radiological findings in order to reach an accurate diagnosis. Since the majority of lung cancer patients have an advanced stage at diagnosis, a cytological specimen is frequently the only material available for diagnosis and further prognostic/predictive marker determination. Several types of specimens can be obtained from the respiratory system (including sputum, bronchoalveolar lavage, bronchial brushing, fine needle aspiration, and pleural fluid) with different technical preclinical management protocols and different diagnostic yields. Immunocytochemistry (ICC) has a pivotal role in the determination of diagnostic, prognostic, and predictive markers. Therefore, limited cytology samples are to be used with a cell-sparing approach, to allow both diagnostic ICC evaluation as well as predictive marker assessment by ICC or specific molecular assays. In this review, we describe the most common ICC markers used for the diagnosis and prognostic/predictive characterization of thoracic tumors in different cytological specimens.

Hyper-phosphorylation of Rb S249 together with CDK5R2/p39 overexpression are associated with impaired cell adhesion and epithelial-to-mesenchymal transition: Implications as a potential lung cancer grading and staging biomarker

Prediction of lung cancer metastasis relies on post-resection assessment of tumor histology, which is a severe limitation since only a minority of lung cancer patients are diagnosed with resectable disease. Therefore, characterization of metastasis-predicting biomarkers in pre-resection small biopsy specimens is urgently needed. Here we report a biomarker consisting of the phosphorylation of the retinoblastoma protein (Rb) on serine 249 combined with elevated p39 expression. This biomarker correlates with epithelial-to-mesenchymal transition traits in non-small cell lung carcinoma (NSCLC) cells. Immunohistochemistry staining of NSCLC tumor microarrays showed that strong phospho-Rb S249 staining positively correlated with tumor grade specifically in the squamous cell carcinoma (SCC) subtype. Strong immunoreactivity for p39 positively correlated with tumor stage, lymph node invasion, and distant metastases, also in SCC. Linear regression analyses showed that the combined scoring for phospho-Rb S249, p39 and E-cadherin in SCC is even more accurate at predicting tumor staging, relative to each score individually. We propose that combined immunohistochemistry staining of NSCLC samples for Rb phosphorylation on S249, p39, and E-cadherin protein expression could aid in the assessment of tumor staging and metastatic potential when tested in small primary tumor biopsies. The intense staining for phospho-Rb S249 that we observed in high grade SCC could also aid in the precise sub-classification of poorly differentiated SCCs.

Molecular genetic alterations in thyroid transcription factor 1-negative lung adenocarcinoma in cytology specimens: A subset with aggressive behavior and a poor prognosis

BACKGROUND

Patients with thyroid transcription factor 1 (TTF1)-negative pulmonary adenocarcinoma (ADC) have been reported to have a worse prognosis and to lack epidermal growth factor receptor (EGFR) mutations. This study describes a series of cytology specimens from patients with clinically confirmed pulmonary carcinoma negative for TTF1.

METHODS

A search for TTF1-negative ADC from 2010 to 2017 was performed. Each patient's clinical history, pathology specimens, and molecular results were noted. Two hundred ten patients with TTF1-positive pulmonary ADC formed the control group.

RESULTS

Fifty specimens were identified from 50 patients (26 females and 24 males). The median age was 58.5 years. The smoking history was as follows: 38 smokers/former smokers (76%), 10 nonsmokers (20%), and 2 patients with an unknown status (4%). Thirty-nine patients (78%) had no previous history of malignancy. The clinical stages were as follows: stage I or II (n = 2 [4%]), stage III (n = 9 [18%]), stage IV (n = 37 [74%]), and unknown (n = 2 [4%]). Patients' mean survival was 10.3 months. Molecular results were available in 43 cases. Twenty-seven cases (63%) had no mutation identified; when they were compared with the control group, TTF1-negative patients had overall shorter survival (P = .0047), even though no statistically significant difference was seen on the clinical stage. Known mutations were less frequent (P = .0095) in TTF-negative tumors (KRAS mutations, n = 11 [25%]; anaplastic lymphoma kinase [ALK], n = 3 [7%]; and EGFR, n = 2 [5%]). This was particularly true for EGFR mutations (P = .047). However, ALK rearrangements were present at an increased frequency in the TTF1-negative group (P = .018).

CONCLUSIONS

Patients with TTF1-negative lung ADC have worse overall survival, a lower frequency of known mutations, and a higher frequency of ALK alterations.

Pulmonary Non-Small Cell Carcinoma With Morphologic Features of Adenocarcinoma or "Non-Small Cell Carcinoma Favor Adenocarcinoma" in Cytologic Specimens Share Similar Clinical and Molecular Genetic Characteristics

OBJECTIVES

Define if the presence of morphologic features of adenocarcinoma (ACA) in non-small cell lung carcinoma (NSCLC) on cytology specimens correlates with clinical and biologic features.

METHODS

A total of 209 cases of NSCLC diagnosed on fine-needle aspiration in a 3-year period were included.

RESULTS

After morphologic review, the cases were classified as ACA (n = 115), NSCLC favor ACA (n = 43), and NSCLC-not otherwise specified (NOS) (n = 18). Squamous cell (SCC) (n = 14) and NSCLC favor SCC (n = 19) were excluded from further analysis. Patients with EGFR-mutated tumors had longer overall survival than those with EGFR wild-type tumors (P = .01). When comparing cases with morphologic features of ACA, NSCLC favor ACA, and NSCLC-NOS, there were no differences in the presence or absence of tested mutations, clinical stage, or survival.

CONCLUSION

Patients diagnosed with pulmonary ACA, NSCLC favor ACA, or NSCLC-NOS in cytology specimens have similar clinical stage, survival, and molecular alterations.

Automated Classification of Lung Cancer Types from Cytological Images Using Deep Convolutional Neural Networks

Lung cancer is a leading cause of death worldwide. Currently, in differential diagnosis of lung cancer, accurate classification of cancer types (adenocarcinoma, squamous cell carcinoma, and small cell carcinoma) is required. However, improving the accuracy and stability of diagnosis is challenging. In this study, we developed an automated classification scheme for lung cancers presented in microscopic images using a deep convolutional neural network (DCNN), which is a major deep learning technique. The DCNN used for classification consists of three convolutional layers, three pooling layers, and two fully connected layers. In evaluation experiments conducted, the DCNN was trained using our original database with a graphics processing unit. Microscopic images were first cropped and resampled to obtain images with resolution of 256 × 256 pixels and, to prevent overfitting, collected images were augmented via rotation, flipping, and filtering. The probabilities of three types of cancers were estimated using the developed scheme and its classification accuracy was evaluated using threefold cross validation. In the results obtained, approximately 71% of the images were classified correctly, which is on par with the accuracy of cytotechnologists and pathologists. Thus, the developed scheme is useful for classification of lung cancers from microscopic images.

The role of the cytopathologist in subtyping and epidermal growth factor receptor testing in non-small cell lung cancer: An institutional experience

OBJECTIVE

Approximately 10% of non-small-cell lung cancer (NSCLC) remains unclassifiable as NSCLC-not otherwise specified (NOS), after using a panel of immunomarkers. The present study was undertaken to assess sensitivity and specificity of immunomarkers in sub-typing NSCLC on fine needle aspiration cytology (FNAC). Epidermal growth factor receptor (EGFR) mutations were also detected in these samples.

METHODS

Sixty cases of NSCLC including 15 squamous cell carcinoma (SCC), 15 adenocarcinomas (ADC) and 30 NSCLC-NOS reported on FNAC were included in the study. A panel of CK7, CK5/6, TTF-1 and p63 was applied in these cases. DNA was extracted from 54 cases including 14 effusion samples, and EGFR mutations were detected.

RESULTS

Classic ADC cases (n=15) showed 73.3% TTF-1 positivity and 100% CK7 positivity. Two cases of ADC showed aberrant expression of p63 and 2 cases showed CK5/6 positivity. 80% of classic SCC cases (n=15) showed strong nuclear p63 positivity and 86.6% were positive for CK5/6. TTF-1 was seen exclusively in ADC cases. Immunohistochemistry (IHC) using two immunomarkers (TTF-1 and p63) helped in subtyping 24/30(80%) cases of NSCLC. EGFR mutations were detected in 9/54 (16.7%) cases, and the most common mutation was short in-frame deletion in Exon 19.

CONCLUSIONS

More than 90% of NSCLC can be sub-typed on cytology samples with the help of immunochemistry. The sensitivity of TTF-1, p63, CK5/6 and CK7 was 73.3%, 80%, 100% and 100%, respectively. The specificity of TTF-1, p63, CK5/6 and CK7 was 100%, 86.6%, 86.6% and 93.3%, respectively. TTF-1 is highly specific, and almost 80% of NSCLC-NOS cases can be sub-typed using TTF-1 and p63. EGFR mutations can be detected in cytology samples, and 16.7% samples were positive for EGFR mutations.

Nonsmall cell lung carcinoma: diagnostic difficulties in small biopsies and cytological specimens

The pathological and molecular classification of lung cancer has become substantially more complex over the past decade. For diagnostic purposes on small samples, additional stains are frequently required to distinguish between squamous cell carcinoma and adenocarcinoma. Subsequently, for advanced nonsquamous cell nonsmall cell lung carcinoma (NSCLC) patients, predictive analyses on epidermal growth factor receptor, anaplastic lymphoma kinase and ROS1 are required. In NSCLCs negative for these biomarkers, programmed death ligand-1 immunohistochemistry is performed. Small samples (biopsy and cytology) require “tissue” management, which is best achieved by the interaction of all physicians involved.

Improving molecular testing and personalized medicine in non-small-cell lung cancer in Ontario

BACKGROUND

Although molecular testing has become standard in managing advanced nonsquamous non-small-cell lung cancer (nsclc), most patients undergo minimally invasive procedures, and the diagnostic tumour specimens available for testing are usually limited. A knowledge translation initiative to educate diagnostic specialists about sampling techniques and laboratory processes was undertaken to improve the uptake and application of molecular testing in advanced lung cancer.

METHODS

A multidisciplinary panel of physician experts including pathologists, respirologists, interventional thoracic radiologists, thoracic surgeons, medical oncologists, and radiation oncologists developed a specialty-specific education program, adapting international clinical guidelines to the local Ontario context. Expert recommendations from the program are reported here.

RESULTS

Panel experts agreed that specialists procuring samples for lung cancer diagnosis should choose biopsy techniques that maximize tumour cellularity, and that conservation strategies to maximize tissue for molecular testing should be used in tissue processing. The timeliness of molecular reporting can be improved by pathologist-initiated reflex testing upon confirmation of nonsquamous nsclc and by prompt transportation of specimens to designated molecular diagnostic centres. To coordinate timely molecular testing and optimal treatment, collaboration and communication between all clinicians involved in diagnosing patients with advanced lung cancer are mandatory.

CONCLUSIONS

Knowledge transfer to diagnostic lung cancer specialists could potentially improve molecular testing and treatment for advanced lung cancer patients.

Accuracy of cytology in sub typing non small cell lung carcinomas

BACKGROUND

Sub typing of non small cell lung carcinoma (NSCLC) has an important task in the era of molecular and targeted therapies. Differentiating between squamous cell carcinoma (SQCC) and adenocarcinoma (ADC) is challenging when limited material is available in lung carcinoma. We investigated the accuracy and feasibility of sub typing NSCLCs in cytology and small biopsy material.

METHODS

Concurrent cytology and biopsy material obtained in a single CT- guided procedure in lung carcinoma over a year period retrospectively. Both materials were individually sub typed and analyzed. Immunohistochemistry (IHC) was performed. Accuracy was determined by comparing the results with IHC.

RESULTS

Total 107 of 126 cases of NSCLCs were included for analysis, where both cytology and biopsy material were adequate for interpretation. FNAC allowed tumor typing in 83 (77.6%) cases; 36 (33.6%) were ADC, 47 (43.9%) cases were SQCC and 24 (22.4%) cases diagnosed as Non-small cell carcinoma not otherwise specified (NSCLC-NOS). In biopsy, 86 cases (80.4%) were typed, among which 34 (31.8%) were ADC, 52 (48.6%) were SQCC and 21 (19.6%) were of NSCLC-NOS type. The result of Chi-square index was significant. With the aid of IHC, NSCLC-NOS reduced from 14 (13%) cases to 2 (1.9%) cases.

CONCLUSION

Cytology and small biopsy specimens achieved comparable specificity and accuracy in sub-typing NSCLC and optimal results were obtain when findings from both modalities combine. The advantage of paired specimens is to maximize overall diagnostic yield and the remaining material will be available for ancillary technique like IHC or for molecular testing. Diagn. Cytopathol. 2017;45:598-603. © 2017 Wiley Periodicals, Inc.

Inaccuracy of lung adenocarcinoma subtyping using preoperative biopsy specimens

BACKGROUND

The prognostic significance of the new classification of lung adenocarcinoma proposed in the 2015 World Health Organization guideline has been validated. This study aimed to compare the preoperative classification of the adenocarcinoma subtype based on computed tomography-guided 18-gauge core needle biopsy (CTNB) or radial probe endobronchial ultrasound (R-EBUS) specimens, with the postoperative classification based on the resected specimens.

METHODS

We retrospectively analyzed a consecutive series of 128 patients (60 CTNB and 68 R-EBUS) who underwent surgery for preoperatively confirmed lung adenocarcinoma between 2010 and 2014. Comprehensive histological subtyping was performed according to the 2015 World Health Organization classification system. Diagnostic concordance of subtypes between small biopsy and resection specimens was assessed.

RESULTS

Concordant subtyping of adenocarcinomas between the predominant pattern on resections and biopsy sections was observed in 58.6% of cases (75 of 128; 95% confidence interval [CI], 49.9%-66.8%). Preoperative subtyping was accurate in only 30% of samples (3 of 10) with a predominance of solid patterns. None of the 5 micropapillary predominant cases was detected by CTNB or R-EBUS. For the concordance of the presence or absence of micropapillary/solid component, the sensitivity was as low as 16.5% (95% CI, 9.1%-26.5%). The detection rate by CTNB/R-EBUS increased with the increase in the percentage of micropapillary/solid component; however, even in the ≥40% micropapillary/solid group, only 24% of cases were detected by CTNB/R-EBUS.

CONCLUSIONS

The accuracy of the estimation of adenocarcinoma histological subtype based on preoperative biopsy sections was unsatisfactory.

Accuracy and Adequacy of Computed Tomography-Guided Lung Biopsies: Experience From a Community Hospital

CONTEXT

Small tissue biopsies obtained through minimally invasive methods have become the primary diagnostic tools for the pathologic characterization and testing of lung masses. In view of recent advances in targeted therapy for non-small cell lung carcinoma, and lung adenocarcinoma in particular, pathologists are now expected to thoroughly characterize lung lesions microscopically while making certain that enough tissue remains for potential molecular analysis if indicated.

OBJECTIVE

To report our experience with computed tomography (CT)-guided lung needle biopsies with particular concentration on diagnostic yield, diagnostic accuracy, and adequacy of tissue for molecular testing if indicated.

METHODS

A retrospective observational study analyzed 224 biopsies in 222 patients undergoing CT-guided lung needle biopsies. Accuracy of diagnosis and adequacy of tissue for molecular testing, if applicable, was evaluated. A standardized protocol for specimen evaluation, triage, and processing was used. This protocol included intraprocedural real-time microscopic specimen evaluation and triage by a pathologist and use of a histologic protocol specifically designed to conserve tissue for ancillary testing. The initial biopsy was considered successful if the specimen was malignant, had specific benign features, or had nonspecific benign features with follow-up supporting benign lesion. Initial biopsy failure cases were those with inadequate tissue or a nonspecific result with highly suspicious imaging or clinical findings.

RESULTS

Of the 224 biopsies, 8 cases with benign but nonspecific findings lacked follow-up and were excluded from the study. The biopsy was diagnostically successful in 189 of 216 (88%) cases. Of these 189 cases, 154 (81%) were malignant, and 35 (19%) were benign. There were 28 diagnostic failures. Subsequent tissue sampling of 13 of 28 diagnostic failures found 9 (69%) to be malignant. Molecular studies were requested on 25 cases: 24 had sufficient material for some of the requested tests, and 20 had enough tissue for all requested testing.

CONCLUSION

A standardized protocol and team approach for CT-guided lung needle biopsy optimizes the ability to achieve a high accurate diagnostic yield with adequate tissue for molecular testing.

Big data from small samples: Informatics of next-generation sequencing in cytopathology

The rapid adoption of next-generation sequencing (NGS) in clinical molecular laboratories has redefined the practice of cytopathology. Instead of simply being used as a diagnostic tool, cytopathology has evolved into a practice providing important genomic information that guides clinical management. The recent emphasis on maximizing limited-volume cytology samples for ancillary molecular studies, including NGS, requires cytopathologists not only to be more involved in specimen collection and processing techniques but also to be aware of downstream testing and informatics issues. For the integration of molecular informatics into the clinical workflow, it is important to understand the computational components of the NGS workflow by which raw sequence data are transformed into clinically actionable genomic information and to address the challenges of having a robust and sustainable informatics infrastructure for NGS-based testing in a clinical environment. Adapting to needs ranging from specimen procurement to report delivery is crucial for the optimal utilization of cytology specimens to accommodate requests from clinicians to improve patient care. This review presents a broad overview of the various aspects of informatics in the context of NGS-based testing of cytology specimens. Cancer Cytopathol 2017;125:236-244. © 2016 American Cancer Society.

Endobronchial Ultrasound-Radial Probe-Assisted Cryobiopsy for Peripheral Lung Mass: A New Way for Better Yield?

Solitary pulmonary nodules pose a diagnostic challenge as traditional techniques like bronchoscopic transbronchial biopsies or percutaneous transthoracic needle biopsies suffer either from poor yield or unacceptable complications. The advent of endobronchial ultrasound (EBUS)-radial probe (RP) has helped to guide the operator to the lesion more accurately and thereby improve yield. Small biopsy forceps or cytology brushes can be passed through the guide sheath of the EBUS-RP, after removing the probe, to get specimens. However, a small specimen may sometimes prove inadequate for special molecular studies or genetic analysis. Recently, there have been feasibility reports of transbronchial cryobiopsies that can be safely performed with larger biopsy specimens. We report a case of solitary pulmonary nodules where EBUS-RP was used to guide a cryoprobe to get large transbronchial cryobiopsies successfully.

The impact of immunohistochemistry on the classification of lung tumors

INTRODUCTION

To highlight the role of immunohistochemistry to lung cancer classification on the basis of existing guidelines and future perspectives.

AREAS COVERED

Four orienting key-issues were structured according to an extensive review on the English literature: a) cancer subtyping; b) best biomarkers and rules to follow; c) negative and positive profiling; d) suggestions towards an evidence-based proposal for lung cancer subtyping. A sparing material approach based on a limited number of specific markers is highly desirable. It includes p40 for squamous cell carcinoma ('no p40, no squamous'), TTF1 for adenocarcinoma, synaptophysin for neuroendocrine tumors and vimentin for sarcomatoid carcinoma. A close relationship between genotype and phenotype also supports a diagnostic role for negative profiles. Expert commentary: Highly specific and sensitive IHC markers according to positive and negative diagnostic algorithms seem appropriate for individual patients' lung cancer subtyping.

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.

Utility of immunochemistry in cytology

Background:

The role played by cytology in primary diagnosis is undeniable. With improved management protocols and targeted therapy, the need for accurate diagnosis has become mandatory. Immunochemistry and molecular techniques are increasingly being used on limited tissue samples.

Aims:

This study was conducted to find out the impact of immunocytochemistry (ICC) on cytology material in cytology practice.

Materials and Methods:

Immunochemistry was done on alcohol-fixed smears and cell-block preparations. It was done with i6000 BioGenex autostainer using BioGenex reagents.

Results:

A total of 148 cases occurring over a period of 3 years (September 2010-June 2013) were analyzed. Staining was done on cytology smears in 77 cases and on cell-block sections in 71 cases. ICC helped in diagnosis in 8 cases, confirmed the diagnosis in 26 cases, helped in subtyping in 60 cases, and helped in prognostication in 6 cases. ICC has altered the diagnosis in two cases. It was noncontributory in 43 cases, and the material was inadequate in three cases.

Conclusion:

In 102 cases (69%), ICC proved to be a useful adjunct in the diagnosis and prognostication; hence, its use is recommended in practice to aid in cytology services.

Diagnostic concordance of non-small cell lung carcinoma subtypes between biopsy and cytology specimens obtained during the same procedure

BACKGROUND

The objectives of this study were: 1) to determine the diagnostic concordance of non-small cell lung carcinoma (NSCLC) subtypes in cytology and biopsy specimens taken during the same procedure and evaluate the causes of discordance; and 2) to determine the frequency of immunohistochemistry (IHC) use for subtyping NSCLC.

METHODS

Biopsy and cytology specimens that were obtained at the same procedure and diagnosed as NSCLC between January 2011 and December 2014 at the McGill University Health Center were identified (n = 226 pairs). The diagnostic concordance between the 2 methods was evaluated. The slides from discordant cases were reviewed, and final diagnoses were made based on IHC, resection specimens, or pathologist discussion.

RESULTS

Concordance in subtype diagnosis was perfect (adeno-adeno or squamous-squamous) in 66.2% of cases and was partial (adeno or squamous vs non-small cell) in 23%; discordance (adeno vs squamous) was observed in 7.8%. Although subtyping was not possible (ie, the final diagnosis was NSCLC, not otherwise specified) in 12.8% of biopsy specimens and 16.3% of cytology specimens, specific subtyping was not achieved in only 3% of cases when both modalities were considered. IHC was used in 47% of biopsy cases and 13% of cytology cases.

CONCLUSIONS

Subtyping of NSCLC can be achieved in most cases (97%) by considering findings in both biopsy and cytology specimens, and concordance in subtyping between cytology and biopsy specimens can be reached in a high percentage of cases (89.2%). Cancer Cytopathol 2016;124:737-43. © 2016 American Cancer Society.

Biomarker Testing in Lung Carcinoma Cytology Specimens: A Perspective From Members of the Pulmonary Pathology Society

The advent of targeted therapy in lung cancer has heralded a paradigm shift in the practice of cytopathology with the need for accurately subtyping lung carcinoma, as well as providing adequate material for molecular studies, to help guide clinical and therapeutic decisions. The variety and versatility of cytologic-specimen preparations offer significant advantages to molecular testing; however, they frequently remain underused. Therefore, evaluating the utility and adequacy of cytologic specimens is critical, not only from a lung cancer diagnosis standpoint but also for the myriad ancillary studies that are necessary to provide appropriate clinical management. A large fraction of lung cancers are diagnosed by aspiration or exfoliative cytology specimens, and thus, optimizing strategies to triage and best use the tissue for diagnosis and biomarker studies forms a critical component of lung cancer management. This review focuses on the opportunities and challenges of using cytologic specimens for molecular diagnosis of lung cancer and the role of cytopathology in the molecular era.

Napsin A/p40 antibody cocktail for subtyping non-small cell lung carcinoma on cytology and small biopsy specimens

BACKGROUND

Subtyping non-small cell lung carcinomas (NSCLC) into adenocarcinoma (ACA) or squamous cell carcinoma (SQCC) is important for treatment and specimen triage for molecular studies. To preserve tissue for molecular studies in cytology/small biopsy specimens, a 2-antibody cocktail for NSCLC subtyping was developed.

METHODS

Markers for lung ACA (thyroid transcription factor 1 and napsin A) and SQCC (cytokeratin 5/6 and p40) were evaluated on tissue microarrays (TMAs) with 143 ACA and 98 SQCC specimens. The napsin A/p40 combination was selected for NSCLC subtyping and validated on the TMA as well as on a cohort of cell block/small biopsy specimens from 80 poorly differentiated NSCLCs.

RESULTS

Using TMA analysis, the napsin A-positive (+)/p40± immunophenotype identified ACA with 94% sensitivity and 100% specificity, whereas the napsin A (negative)-/p40+ immunophenotype identified SQCC with 100% sensitivity and specificity. On the validation cohort of 80 cell block and small biopsy specimens, the napsin A/p40 cocktail accurately subtyped 63 of 70 NSCLC (90%) as ACA or SQCC using the subsequent surgical resection as reference histology. Of the remaining 17 cases, 15 were classified as NSCLC-not otherwise specified based on a napsin A-/p40- immunophenotype; their corresponding resections were diagnosed as ACA (7 cases), large cell carcinoma (7 cases), or pleomorphic carcinoma (1 case). Two additional large cell carcinoma cases showed a napsin A-/p40+ or napsin A+/p40+ profile in the preoperative cell block/small biopsy sample.

CONCLUSIONS

A napsin A/p40 cocktail can accurately subtype NSCLC into ACA and SQCC in most cell block/small biopsy specimens of poorly differentiated NSCLC. In the minority of cases in which the napsin A/p40 immunophenotype is indeterminate, additional stains may be necessary for precise classification. Cancer Cytopathol 2016;124:472-84. © 2016 American Cancer Society.

Pneumothorax with prolonged chest tube requirement after CT-guided percutaneous lung biopsy: incidence and risk factors

PURPOSE

To evaluate the incidence and risk factors of pneumothoraces requiring prolonged maintenance of a chest tube following CT-guided percutaneous lung biopsy in a retrospective, single-centre case series.

MATERIALS AND METHODS

All patients undergoing CT-guided percutaneous lung biopsies between June 2012 and May 2014 who required chest tube insertion for symptomatic or enlarging pneumothoraces were identified. Based on chest tube dwell time, patients were divided into two groups: short term (0-2 days) or prolonged (3 or more days). The following risk factors were stratified between groups: patient demographics, target lesion characteristics, and procedural/periprocedural technique and outcomes.

RESULTS

A total of 2337 patients underwent lung biopsy; 543 developed pneumothorax (23.2 %), 187 required chest tube placement (8.0 %), and 55 required a chest tube for 3 days or more (2.9 % of all biopsies, 29.9 % of all chest tubes). The median chest tube dwell time for short-term and prolonged groups was 1.0 days and 4.7 days, respectively. The transfissural needle path predicted prolonged chest tube requirement (OR: 2.5; p = 0.023). Other factors were not significantly different between groups.

CONCLUSION

Of patients undergoing CT-guided lung biopsy, 2.9 % required a chest tube for 3 or more days. Transfissural needle path during biopsy was a risk factor for prolonged chest tube requirement.

KEY POINTS

• CT-guided percutaneous lung biopsy (CPLB) is an important method for diagnosing lung lesions • A total of 2.9 % of patients require a chest tube for ≥3 days following CPLB • Transfissural needle path is a risk factor for prolonged chest tube time.

[Squamous cell carcinoma, basaloid squamous cell carcinoma and adenosquamous carcinoma in the lung]

The precise distinction between adenocarcinoma and squamous cell carcinoma (SqCC) has become very important for determining the appropriate therapy for patients and more specifically to drive the use of tyrosine kinase inhibitors, pemetrexed, anti-VEGF monoclonal antibody and crizotinib. Squamous pearls and distinct intercellular bridges identify keratinizing SqCC. In non-keratinizing SqCC, immuno-histochemistry is required. Recent studies have shown p40 and TTF1 to be the two best markers of SqCC and adenocarcinoma respectively. Many morphological variants of SqCC have been described. Basaloid SqCC is a poorly differentiated epithelial tumor lacking squamous morphology but showing immuno-histochemical expression of squamous makers. The pronostic of basaloid carcinoma is considered poorer than that of other non-small cell lung cancers. Adenosquamous carcinoma shows components of both SqCC and adenocarcinoma. Both components must be clearly identified either on H&E or by immuno-histochemistry. The adenocarcinoma components justified a screening for gene rearrangements. Finally, the recent WHO classification of lung tumors did not change the criteria applying for the grading of preinvasive bronchial lesion.

[Large cell carcinoma, lymphoepithelioma-like carcinoma, NUT carcinoma]

The diagnosis of large cell carcinoma can only be made on a sampled resected tumor and should not be applied to biopsies or cytology. In the 2015 WHO classification, the definition of large cell carcinoma is restricted to carcinomas both lacking morphological signs of glandular, squamous or neuroendocrine differentiation and exhibiting a null or unclear phenotype (TTF1-/p40 ou p63 ou CK5/6+ focally). These carcinomas have an adenocarcinoma molecular profile because they harbor a significant number of KRAS and BRAF mutations, a profile that is more similar to adenocarcinoma than squamous cell carcinoma. They also have a worse prognosis than the other types of non-small cell lung carcinoma. Many large cell carcinomas previously classified on morphological data alone are now reclassified in the adenocarcinoma and squamous cell carcinoma types, including immunohistochemical features. The other large cell carcinoma subtypes from the 2004 WHO classification, i.e. large cell neuroendocrine carcinoma and basaloid carcinoma, are grouped respectively with the other neuroendocrine tumors and squamous cell carcinomas. Clear cell and rhabdoid features are now considered as cytological variants that can occur in any histopathological subtype and not as distinct subtypes. Lymphoepithelioma-like carcinoma is moved to the group of other and unclassified carcinomas as NUT carcinoma.

Recent advances in the pathology and molecular genetics of lung cancer: A practical review for cytopathologists

Lung cancer is one of the most common causes of cancer-related death worldwide. Better understanding of the molecular genetic characteristics of non-small cell lung carcinoma (NSCLC), particularly adenocarcinoma, has opened the opportunity for targeted therapies. With the different molecular abnormalities and the different responses to new targeted therapies based on the histological subtype of NSCLC, there came a need to further classify NSCLC into squamous cell carcinoma and adenocarcinoma, and to perform the appropriate molecular testing in these different subtypes to guide management decisions. Given that approximately 70% of lung cancer patients have only small biopsies or cytology specimens available, incorporating the testing of these specimens into the cytopathology laboratory has been crucial. Herein, we review current concepts and recommendations on NSCLC subtyping and molecular testing that are relevant for the cytopathology community.