Anaplastic lymphoma kinase 5A4 immunohistochemistry as a diagnostic assay in lung cancer: A Canadian reference testing center's results in population-based reflex testing.

BACKGROUND: The presence of anaplastic lymphoma kinase (ALK) rearrangement predicts response to ALK tyrosine kinase inhibitor (TKI) therapy. Fluorescence in situ hybridization (FISH) was the initial reference standard to detect ALK rearrangement, but immunohistochemistry (IHC) using D5F3 has gained acceptance as an alternative diagnostic method. ALK IHC assays using other ALK antibodies have also been used as screening methods, but data supporting their utility as diagnostic tests have not been widely reported. METHODS: Data from reflexive clinical ALK IHC test using the 5A4 clone concurrent with epidermal growth factor receptor (EGFR) mutation testing were analyzed. ALK IHC results were reported as negative (-), equivocal, or positive (+), with equivocal or positive staining validated by FISH break-apart probe testing. Treatment outcomes were reviewed for ALK IHC+ patients. RESULTS: Between 2012 and 2015, 146 (2.5%) cases were reported as ALK IHC+, 188 (3.2%) were reported as equivocal, and 5624 (94.4%) were reported as ALK IHC-. Of the ALK IHC+ cases, 131/143(91.6%) were ALK FISH+. Excluding 6 cases in which FISH was inconclusive or not performed, the positive predictive value was 95.6%, and the negative predictive value was 100%. Most specimens (n = 5352 [89.6%]) were also successfully tested for EGFR. Clinical responses to ALK TKIs were noted in 49 ALK IHC+ patients, with a median progression-free survival of 9.9 months. CONCLUSIONS: ALK 5A4 IHC can serve as a robust diagnostic test for ALK-rearranged lung cancer and is associated with treatment response and survival. Optimized tissue allocation resulted in high success rates of combined reflex EGFR and ALK testing.

Performance of Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration for the Diagnosis of Isolated Mediastinal and Hilar Lymphadenopathy.

BACKGROUND: Although many studies have assessed the diagnostic utility of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in the context of a specific disease, few studies have assessed the overall diagnostic yield, sensitivity, and negative predictive value in patients with isolated mediastinal and hilar lymphadenopathy (IMHL). OBJECTIVE: We evaluated the performance of EBUS-TBNA for diagnosing IMHL in a population with a high prevalence of concurrent or preexisting non-pulmonary malignancy. METHODS: A retrospective chart review of patients who underwent EBUS-TBNA from October 2008 to April 2014 was performed to identify patients with IMHL. Patients with known or suspected primary pulmonary malignancy were excluded. When available, EBUS-TBNA results were cross-referenced with further diagnostic investigation or clinical diagnosis based on follow-up. RESULTS: EBUS-TBNA was used to sample 765 lymph nodes from 350 patients. One hundred and fourteen (33.3%) patients had a concurrent or preexisting non-pulmonary malignancy. The overall yield of EBUS-TBNA for specific diagnosis was 300/350 (86%). The diagnostic yield for sarcoidosis, lymphoproliferative disease, metastatic lymphadenopathy from extrathoracic malignancy, and necrotizing granuloma was 123/149 (83%), 27/33 (82%), 20/25 (80%), and 13/19 (68%), respectively. Amongst 50 patients with non-diagnostic EBUS-TBNA, 25 yielded an insufficient sample and another 25 yielded only benign lymphoid material which was not representative of the underlying pathology. Overall, EBUS-TBNA had a sensitivity of 89%, a diagnostic yield of 86%, and a negative predictive value of 79%. CONCLUSION: For patients with isolated hilar or mediastinal lymphadenopathy and a high background prevalence of concurrent and preexisting non-pulmonary malignancy, EBUS-TBNA is a reliable first-line diagnostic investigation.

Thyroid Biopsy Specialists: A Quality Initiative to Reduce Wait Times and Improve Adequacy Rates.

PURPOSE: To develop and implement a program where selected sonographers would be trained to perform thyroid biopsies independently under the supervision of a radiologist, with the goal of improving efficiency and quality. MATERIALS AND METHODS: Institutional research ethics board approval was obtained for this retrospective study, with waiver of informed consent. After approval from the relevant regulatory bodies, four sonographers successfully completed a training program and began to perform all thyroid biopsies (with informed consent) in a room adjacent to the main radiologist-run biopsy room, where the radiologist was available for backup as needed. In the preimplementation period (January 2010 to April 2011), 1321 nodules were biopsied, 29 of which included on-site cytopathology assessment. In the postimplementation period (August 2011 to July 2012), 1347 nodules were biopsied, 103 of which underwent on-site cytopathology assessment. Wait times and adequacy rates were calculated for both periods. RESULTS: Patient wait times decreased from a mean of 80-90 days before implementation of the thyroid biopsy specialist program to 20-30 days afterward. The percentage of adequate samples improved from 74.6% (985 of 1321 nodules) to 78.6% (1059 of 1347 nodules), with a P value of .015 (74.1% [957 of 1292 nodules] to 77.5% [964 of 1244 nodules] when excluding nodules with on-site cytopathology assessment, P = .0497). The percentage of malignant samples showed no significant change in the two time periods, 5.1% (68 of 1321 nodules) before implementation of the program versus 5.4% (73 of 1347 nodules) after implementation, P = .823 (5.1% [66 of 1292 nodules] vs 5.3% [66 of 1244 nodules] in the respective time periods when excluding nodules with on-site cytopathology assessment, P = .888). No major procedural complications occurred. CONCLUSION: Sonographers can be successfully trained to perform ultrasonography-guided thyroid biopsies safely under the supervision of a radiologist, which can improve wait times and adequacy rates.

Evaluation of indeterminate thyroid cytology by second-opinion diagnosis or repeat fine-needle aspiration: which is the best approach?

OBJECTIVE: This study investigated a published series evaluating the role of second-opinion diagnosis (SOD) or repeat fine-needle aspiration cytology (RFNA) for indeterminate thyroid aspirates. STUDY DESIGN: Twenty-three studies were selected and the following parameters were analyzed: disagreement between SOD or RFNA and the original diagnosis (OD), reclassification of OD according to the Bethesda system for reporting thyroid cytopathology, the rate of definitive diagnosis and the diagnostic performance of SOD and RFNA. RESULTS: 7,154 thyroid FNAs were retrieved from 9 studies that investigated the role of SOD, including 1,048 (14.6%) cases originally reported as indeterminate. The 14 studies that analyzed the role of thyroid RFNA comprised 67,581 FNAs and included 7,246 (10.7%) indeterminate cases. A definitive diagnosis was achieved by SOD in 450 cases (42.9%) and RFNA in 1,645 cases (57.2%, p=0.0001). Based on cases with histological follow-up, SOD demonstrated significantly higher rates of positive predictive value and accuracy than RFNA (55.8 vs. 37.7%, p=0.0001; 67.4 vs. 56.0%, p=0.0034, respectively). CONCLUSIONS: Both SOD and RFNA demonstrated an improvement in the diagnosis of initially indeterminate thyroid FNAs. RFNA achieved a definitive diagnosis for the majority of indeterminate cases. Regarding histological follow-up, SOD was shown to be more accurate than RFNA.

Molecular yield and cytomorphologic assessment of fine needle aspiration specimen supernatants.

INTRODUCTION: Cytology samples are frequently relied upon for the diagnosis of advanced cancer such as lung cancer. As the recommendations for solid malignancies biomarker testing continue to expand, it becomes increasingly important to efficiently utilize limited specimens to minimize the need for additional sampling and its associated risks and costs. MATERIALS AND METHODS: We performed molecular testing on fresh or CytoLyt-fixed supernatants derived from fine needle aspirates (FNAs) and compared its performance against the clinical specimen (including formalin-fixed paraffin-embedded cell blocks, residual PreservCyt and fresh samples). Supernatants were assessed for cellularity using Field-stained Cytospin (CS) preparations. RESULTS: There was overall almost perfect agreement (41/45 cases, K = 0.822) and substantial to almost perfect agreement in molecular testing results of clinically actionable variants between fresh (20/23 cases, Κ = 0.742) and CytoLyt-fixed (21/22 cases, Κ = 0.908) and its clinical specimen counterpart. Interestingly, CS examination of the supernatants revealed viable tumor cells. Centrifugation for 1 minute at 300 rpm is optimal for overall or tumor cellularity recovery. Delayed molecular testing after 3, 4 and 7 days at 4 degrees Celsius showed identical molecular results. CONCLUSIONS: We validated the use of supernatants derived from FNA cytology samples as a substrate for molecular testing using next-generation sequencing and other molecular techniques.

Validation of BRCA testing on cytologic samples of high-grade serous carcinoma.

BACKGROUND: Testing for BRCA1/2 gene alterations in patients with high-grade serous carcinoma (HGSC) is a critical determinant of treatment eligibility for poly(adenosine diphosphate-ribose) polymerase inhibitors in addition to providing vital information for genetic counselling. Many patients present with effusions necessitating therapeutic drainage, and this makes cytologic specimens (CySs) the initial diagnostic material for HGSC, often before histologic sampling. Initiating somatic BRCA testing on a CyS allows the BRCA status to be determined sooner, and this affects clinical management. METHODS: Retrospectively, 8 cases of formalin-fixed, paraffin-embedded (FFPE) CySs of peritoneal or pleural fluid from patients with HGSC and known BRCA1/2 alterations previously established by the testing of FFPE surgical specimens (SpSs) underwent next-generation sequencing (NGS). Prospectively, 11 cases of peritoneal or pleural fluid from patients with HGSC but an unknown BRCA1/2 status underwent NGS with fresh, alcohol-fixed, and FFPE CySs, and they were compared with subsequent NGS on 4 SpSs. RESULTS: CySs yielded high-quantity and high-quality DNA for NGS analysis when sufficient tumor cellularity was present. Fresh, alcohol-fixed, and FFPE CySs were all suitable for NGS and provided identical NGS results. SpS and CyS BRCA testing was concordant in 10 of 12 cases. The 2 discordant cases showed low tumor cellularity and quality in the CyS and the SpS, respectively. CONCLUSION: Effusion CySs of HGSC are excellent sources for NGS testing for BRCA1/2 genetic alterations when sufficient tumor cellularity is present. Fresh, alcohol-fixed, and FFPE CySs are equivalent for NGS of BRCA1/2. NGS testing of HGSC CySs demonstrates good concordance with SpSs for the BRCA1/2 status.

Long-Term Impact of Thyroid Biopsy Specialists on Efficiency and Quality of Thyroid Biopsy.

OBJECTIVE: To assess consistency and long-term progress in thyroid biopsy performed by trained sonographers under supervision of a radiologist. METHODS: Trained sonographers started performing thyroid biopsy at our institute in August 2011. The data for this study were extracted from a prospectively maintained database for ultrasound guided thyroid biopsy and included the number of thyroid fine needle aspiration biopsy procedures performed between August 2011 and 2016 and the final cytopathology report as per the Bethesda Classification. For the analysis, the study was divided into two time periods: initial postimplementation period (August 2011 to 2013) and late postimplementation period (2014-2016). RESULTS: In all, 5,538 thyroid biopsies were performed by trained sonographers in the period, 2,561 in the initial implementation period and 2,977 between 2014 and 2016. The unsatisfactory rates dropped from 21% to 10% in the two periods (P < .001), and the proportion of malignant nodules on cytopathology increased from 6% to 7% in the two periods (P = .010). Wait times for thyroid biopsies remained low during the period. CONCLUSION: Sonographers trained to perform ultrasound guided thyroid biopsies provide persistent improved patient care over a long-term period. This reinforces the role of physician extenders in targeted scopes of practice.

Implementation of PD-L1 22C3 IHC pharmDxTM in Cell Block Preparations of Lung Cancer: Concordance with Surgical Resections and Technical Validation of CytoLyt® Prefixation.

BACKGROUND: Programmed death ligand-1 (PD-L1) assessed by immunohistochemistry (IHC) is used as biomarker for pembrolizumab therapy in advanced stage lung cancer patients. However, data permitting direct performance comparison between cytology and surgical specimen types are limited since both specimens from a single tumor site are infrequently available. In addition, alcohol fixation used with cytology specimens requires technical validation of the PD-L1 IHC assay before clinical use. We here report our experience with implementation of the PD-L1 22C3 IHC pharmDxTM assay for cytologic samples at a large tertiary cancer center. STUDY DESIGN: Archival formalin-fixed (FF), paraffin-embedded cell blocks (CBs) and subsequent lung tumor resections (LTRs) from the same anatomical site were used for a direct comparison of PD-L1 tumor proportion scores (TPSs). TPS values were independently determined by one surgical lung pathologist and two cytopathologists blinded to the specimen pairs. An interim analysis was performed to facilitate the pooling of expertise among observers. After PD-L1 22C3 IHC pharmDxTM implementation for FF cytology specimens, dual-processed samples were used for a prospective technical validation of CytoLyt® prefixation (CF). Digital image analysis was performed for a subset of dual-processed specimens. RESULTS: Eighty-one CBs and LTRs were included for comparison of the specimen types. PD-L1 assessment in CBs had an accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of 88.9/72.8, 66.7/73.5, 95.2/72.3, 80.0/65.8, and 90.9/79.1% for the ≥50/≥1% cutoff, respectively. The intraclass correlation coefficient was 0.84 (95% confidence interval [CI]: 0.76, 0.90), and it improved after interim analysis (before: 0.79 and after: 0.92). The overall concordance between CF and FF for the categories defined by the ≥50/≥1% cutoff values was 90.4% (95% CI: 79.0, 96.8). Similar assay performance was confirmed by digital analysis. CONCLUSIONS: PD-L1 22C3 IHC pharmDxTM shows good reliability if used with CB preparations. CF does not impact assay results significantly. Clinical validation with outcome data is needed, and digital methods of assessment should be further investigated.

Equivalence of laser scanning cytometric and flow cytometric immunophenotyping of lymphoid lesions in cytologic samples.

The immunophenotype of lymphoid cytologic samples obtained by laser scanning cytometry (LSC) and flow cytometry (FC) was compared in 72 cases composed of a series of 23 cases with simultaneous LSC and FC immunophenotyping and a second series of 49 cases in which nonsimultaneous immunophenotyping was performed. In both series, no discordance in the population immunophenotype was found that would result in changes in diagnostic classification, although minor discordance in some antigens was found, predominantly affecting FMC7, CD11c, and CD23. The immunophenotype obtained by LSC shows a high degree of concordance with that obtained by FC and generates results that are diagnostically equivalent. Potential explanations for the discordant markers include differences related to the techniques, differences in the fluorochrome-labeled antibodies, technical factors, differences in antigen expression related to anatomic sites, temporal variations, and interpretive variances.

Hairy cell leukemia presenting as a discrete liver mass: diagnosis by fine needle aspiration biopsy.

Hairy cell leukemia, a chronic low-grade lymphoproliferative disorder first recognized in mid 1920's typically involves the lymphoreticular system, especially the spleen and the bone marrow. Clinically, it tends to present with pancytopenia and splenomegaly. Liver involvement, if present, is usually in a sinusoidal and a periportal pattern. We report a case of hairy cell leukemia associated with a liver mass 20 years after the initial presentation. To our knowledge, this is the first case of hairy cell leukemia presenting as a solid liver mass diagnosed by a percutaneous ultrasound guided fine needle aspiration biopsy to be reported in the English literature.

Minimally Invasive Real-Time Detection of Actionable Mutations in Patients With Metastatic Solid Tumors Using Fine-Needle and Liquid Biopsies.

PURPOSE: Fine-needle biopsy (FNB) and liquid biopsy are minimally invasive methods of tumor sampling that provide feasible means to assess tumor genotypes in real time. However, more data are needed to establish the strength of these methods by benchmarking against the current gold standard methods, core-needle biopsy (CNB) or surgical excision of the tumor. PATIENTS AND METHODS: Eligible patients with advanced solid tumors were prospectively recruited. We performed mutation profiling using matched tumor DNA obtained by CNB, FNB and liquid biopsy, and matrix-assisted laser desorption/ionization time-of-flight custom mass-spectrometry or targeted next-generation DNA sequencing. The actionability of detected mutations was determined using the OncoKB Web tool. Agreement between mutations detected in CNBs, FNBs, and circulating tumor DNA (ctDNA) was examined. RESULTS: Forty-one patients underwent tumor biopsy. Thirty CNBs (73%) and 34 FNBs (83%) had sufficient tumor and DNA for mutation profiling. Median DNA yield from CNB and FNB were 775 ng (interquartile range, 240 to 347 4ng) and 649 ng (interquartile range, 180 to1350 ng), respectively. Of 29 CNB/FNB pairs available for comparison, actionable mutation results were concordant in 28 (96%). Six of nine actionable mutations (67%) that were found by CNB, FNB, or both were detectable in ctDNA. Two additional actionable mutations were found exclusively in ctDNA. CONCLUSION: Optimally processed FNB and liquid biopsy can be used routinely for tumor mutation profiling to identify actionable mutations.

Cytologic examination of bronchoalveolar lavage fluid from immunosuppressed patients.

Pulmonary infiltrates in immunocompromised patients frequently represent infections. This study was undertaken to evaluate cytologic examination of bronchoalveolar lavage samples and the value of different preparations and silver staining. Over 6 mo, 336 samples were collected from 155 immunosuppressed patients in whom both cytologic and microbiologic studies were performed. In 27 samples, the cytology, microbiology or both demonstrated the presence of infectious agents. In four cases, cytology identified neoplastic process. Cytology had a sensitivity of 34.6% for detection of infection, which increased to 42.9% when Cytomegalovirus was excluded. Cytology detected 6 of 15 cases of Aspergillus, including three cases not detected by microbiology and 3 of 4 cases of Pneumocystis, but did not identify any of the Cytomegalovirus cases. The type of preparations did not affect detection of the organism when present in cytologic samples and silver staining did not appear to have added value in examination of these samples.

The Canadian Area of Focused Competence (AFC) in Cytopathology experience: the first four years.

The AFC in cytopathology program was created in 2012 to address the societal need in Canada for Cytopathology leaders with in-depth specific knowledge of Cytopathology diagnostics, laboratory management, quality assurance and risk management to ensure high quality and accurate patient outcomes. So far, the developed AFC program in Cytopathology has been successfully implemented in three academic centres, and it stands as a model for competency-based advanced training in Cytopathology.

Multiplex sequencing for EZH2, CD79B, and MYD88 mutations using archival cytospin preparations from B-cell non-Hodgkin lymphoma aspirates previously tested for MYC rearrangement and IGH/BCL2 translocation.

BACKGROUND: Gene rearrangements and specific translocations define some B-cell non-Hodgkin lymphoma (NHL) subtypes. Genome-wide mutational studies have revealed recurrent point mutations with prognostic implications. The goals of this study were to evaluate the feasibility of applying a multiplex mutation assay to archival cytospin preparations (CPs) and to investigate the rate of EZH2, CD79B, and MYD88 mutations in B-cell NHL samples previously tested for MYC rearrangement and/or IGH/BCL-2 translocation. METHODS: DNA was extracted from archival CPs of B-cell NHL cases with previous fluorescence in situ hybridization (FISH) assays for MYC rearrangement and/or IGH/BCL-2 translocation. Multiplex sequencing was performed for the detection of EZH2 (Y641), CD79B (Y196), and MYD88 (L265) mutations. Sanger sequencing was applied to samples with positive results and failed assays. RESULTS: Eighty-eight archival CPs were available from 40 patients. Alterations detected by FISH were: MYC rearrangement (10 cases), IGH/BCL-2 translocations (21 cases), dual translocations (6 cases), and other abnormalities for IGH/BCL-2 (23 cases) and for MYC (16 cases). DNA concentration ranged from 1.88 to 62.85 ng/µL (mean, 9.46 ng/µL). Successful results were obtained in 88.0% of the specimens submitted to multiplex sequencing. With Sanger sequencing, 2 additional mutated cases were found, and all cases with mutations were confirmed. Eight specimens showed mutations: 6 for EZH2, 1 for CD79B, and 1 for MYD88. Among them, 5 cases showed concurrent MYC and/or IGH/BCL-2 translocations and 2 revealed abnormal signals of IGH/BCL-2 and MYC. CONCLUSIONS: CPs archived for up to 6 years are a reliable source of high-quality genomic material for multiplex sequencing. Almost all B-cell NHL with point mutations showed concurrent chromosomal abnormalities.

The value of second opinion in thyroid cytology: a review.

BACKGROUND: Second-opinion diagnosis (SOD) on pathological material is an accepted practice before definitive therapy is considered for referred patients. The thyroid gland is an anatomical site prone to diagnostic disagreement between pathologists. We performed a review of the literature that addressed the role of interinstitutional SOD on thyroid fine-needle aspirations (FNAs). METHODS: Nine studies comprising second opinions on thyroid FNAs were selected. The parameters analyzed included: discordances between the initial diagnoses (IDs) and SODs; cytohistologic correlation; changes in the clinical management of the patients with thyroid nodules after SOD. The same parameters were applied to the "indeterminate" diagnostic category comprising cases initially reported as "atypia," "atypia of undetermined significance/follicular lesion of undetermined significance," "suspicious for a follicular neoplasm," "follicular neoplasm," "suspicious," and "suspicious for malignancy." RESULTS: A total of 7154 thyroid FNAs were retrieved, showing an overall discordance rate between ID and SOD of 28.6%. In general, SOD was better supported by clinical follow-up and histological diagnosis, showing higher diagnostic accuracy in comparison with ID. Almost one-third (30.4%) of the discordant cases resulted in changes in the clinical management of patients with thyroid nodules. Numerous thyroid FNAs initially categorized as "indeterminate" were definitively classified as benign or malignant by SOD, with an overall diagnostic resolution rate of 42.5%, sensitivity of 97.9%, and diagnostic accuracy of 73.7%. CONCLUSIONS: Second-opinion review of thyroid FNA improves diagnostic accuracy and potentially changes clinical management. SOD also demonstrates a significative rate of diagnostic resolution for thyroid FNAs originally diagnosed as "indeterminate."

Sample features associated with success rates in population-based EGFR mutation testing.

INTRODUCTION: Epidermal growth factor receptor (EGFR) mutation testing has become critical in the treatment of patients with advanced non-small-cell lung cancer. This study involves a large cohort and epidemiologically unselected series of EGFR mutation testing for patients with nonsquamous non-small-cell lung cancer in a North American population to determine sample-related factors that influence success in clinical EGFR testing. METHODS: Data from consecutive cases of Canadian province-wide testing at a centralized diagnostic laboratory for a 24-month period were reviewed. Samples were tested for exon-19 deletion and exon-21 L858R mutations using a validated polymerase chain reaction method with 1% to 5% detection sensitivity. RESULTS: From 2651 samples submitted, 2404 samples were tested with 2293 samples eligible for analysis (1780 histology and 513 cytology specimens). The overall test-failure rate was 5.4% with overall mutation rate of 20.6%. No significant differences in the failure rate, mutation rate, or mutation type were found between histology and cytology samples. Although tumor cellularity was significantly associated with test-success or mutation rates in histology and cytology specimens, respectively, mutations could be detected in all specimen types. Significant rates of EGFR mutation were detected in cases with thyroid transcription factor (TTF)-1-negative immunohistochemistry (6.7%) and mucinous component (9.0%). CONCLUSIONS: EGFR mutation testing should be attempted in any specimen, whether histologic or cytologic. Samples should not be excluded from testing based on TTF-1 status or histologic features. Pathologists should report the amount of available tumor for testing. However, suboptimal samples with a negative EGFR mutation result should be considered for repeat testing with an alternate sample.

EZH2 and CD79B mutational status over time in B-cell non-Hodgkin lymphomas detected by high-throughput sequencing using minimal samples.

BACKGROUND: Numerous genomic abnormalities in B-cell non-Hodgkin lymphomas (NHLs) have been revealed by novel high-throughput technologies, including recurrent mutations in EZH2 (enhancer of zeste homolog 2) and CD79B (B cell antigen receptor complex-associated protein beta chain) genes. This study sought to determine the evolution of the mutational status of EZH2 and CD79B over time in different samples from the same patient in a cohort of B-cell NHLs, through use of a customized multiplex mutation assay. METHODS: DNA that was extracted from cytological material stored on FTA cards as well as from additional specimens, including archived frozen and formalin-fixed histological specimens, archived stained smears, and cytospin preparations, were submitted to a multiplex mutation assay specifically designed for the detection of point mutations involving EZH2 and CD79B, using MassARRAY spectrometry followed by Sanger sequencing. RESULTS: All 121 samples from 80 B-cell NHL cases were successfully analyzed. Mutations in EZH2 (Y646) and CD79B (Y196) were detected in 13.2% and 8% of the samples, respectively, almost exclusively in follicular lymphomas and diffuse large B-cell lymphomas. In one-third of the positive cases, a wild type was detected in a different sample from the same patient during follow-up. CONCLUSIONS: Testing multiple minimal tissue samples using a high-throughput multiplex platform exponentially increases tissue availability for molecular analysis and might facilitate future studies of tumor progression and the related molecular events. Mutational status of EZH2 and CD79B may vary in B-cell NHL samples over time and support the concept that individualized therapy should be based on molecular findings at the time of treatment, rather than on results obtained from previous specimens. Cancer (Cancer Cytopathol) 2013;121:377-386. © 2013 American Cancer Society.

Diagnosis and subclassification of lymphomas and non-neoplastic lesions involving mediastinal lymph nodes using endobronchial ultrasound-guided transbronchial needle aspiration.

INTRODUCTION: The value of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has been established for staging mediastinal lymph nodes in lung carcinoma patients with radiologically enlarged lymph nodes, but its utility for evaluation of primary lymph node disorders is not well defined. The objective of this study was to evaluate the usefulness of EBUS-TBNA with on-site assessment and triage of sample for multiple ancillary techniques, for the diagnosis and subclassification of lymphomas and non-neoplastic lesions involving mediastinal lymph nodes. METHODS: One hundred and twenty consecutive patients who underwent EBUS-TBNA between January 2008 and August 2009 were reviewed. The final cytological diagnosis was based on air-dried Romanowsky and alcohol-fixed Papanicolaou stained direct smears, immunohistochemistry, immunophenotyping, and fluorescence in situ hybridization (FISH). RESULTS: A total of 38 cases were included in this study consisting of eight reactive lymphoid hyperplasia, 20 granulomatous lymphadenitis (17 non-necrotizing and 3 necrotizing granulomatous inflammations), 3 Hodgkin lymphomas and 7 non-Hodgkin lymphomas (1 small lymphocytic lymphoma (SLL), 1 SLL with scattered Reed-Sternberg cells, 1 marginal zone lymphoma, and 4 large B cell lymphomas). Cultures performed in 13 cases were negative for AFB and fungi. Immunophenotyping and immunohistochemistry for MIB1 in six cases, and FISH in five cases provided necessary information for subclassification. CONCLUSIONS: EBUS-TBNA is a minimally invasive procedure which provides sufficient sample for definitive primary diagnosis and classification of malignant lymphoma and granulomatous inflammation in patients with mediastinal lymphadenopathy. Rapid on-site specimen assessment is invaluable for appropriate assignment of sample to ancillary studies.

Negative images of crystalline immunoglobulin in crystal storing histiocytosis: A potential cytologic mimic of mycobacteria in smears.

Two cases are described of crystal storing histiocytosis (CSH) associated with extranodal marginal zone lymphoma, presenting as lung and subcutaneous masses respectively. Fine-needle aspiration of subcutis and smears prepared from the resected lung masses showed negative images. Cytology slides of both cases were reviewed to identify cytomorphological features for the differential diagnosis between immunoglobulin crystals and mycobacteria. The crystals in CSH consist of straight and needle shaped rods with pointed or angular edges and are more variable in thickness than the uniformly thin mycobacteria. Mycobacteria show a haphazard distribution, whereas crystals are frequently present in parallel arrays. Small lymphoid or plasma cells are identified in the background of CSH, whereas a necrotic and inflammatory background is seen in mycobacteriosis. Additional samples for culture in the case of mycobacteriosis, or flow cytometry and molecular clonality testing in the case of CSH can provide critical data for a definitive diagnosis.