Anja C. Roden

Correlation of IHC and FISH for ALK Gene Rearrangement in Non-small Cell Lung Carcinoma: IHC Score Algorithm for FISH

Introduction: Accurate, cost-effective methods for testing anaplastic lymphoma kinase gene rearrangement (ALK+) are needed to select patients with non-small cell lung carcinoma for ALK-inhibitor therapy. Fluorescent in situ hybridization (FISH) is used to detect ALK+, but it is expensive and not routinely available. We explored the potential of an immunohistochemistry (IHC) scoring system as an affordable, accessible approach. Methods: One hundred one samples were obtained from an enriched cohort of never-smokers with adenocarcinoma from the Mayo Clinic Lung Cancer Cohort. IHC was performed using the ALK1 monoclonal antibody with ADVANCE detection system (Dako) and FISH with dual-color, break-apart probe (Abbott Molecular) on formalin-fixed, paraffin-embedded tissue. Results: Cases were assessed as IHC score 0 (no staining; n = 69), 1+ (faint cytoplasmic staining, n = 21), 2+ (moderate, smooth cytoplasmic staining; n = 3), or 3+ (intense, granular cytoplasmic staining in ≥10% of tumor cells; n = 8). All IHC 3+ cases were FISH+, whereas 1 of 3 IHC 2+ and 1 of 21 IHC 1+ cases were FISH+. All 69 IHC 0 cases were FISH−. Considering FISH a gold-standard reference in this study, sensitivity and specificity of IHC were 90 and 97.8%, respectively, when 2+ and 3+ were regarded as IHC positive and 0 and 1+ as IHC negative. Conclusions: IHC scoring correlates with FISH and may be a useful algorithm in testing ALK+ by FISH in non-small cell lung carcinoma, similar to human epidermal growth factor-2 testing in breast cancer. Further study is needed to validate this approach.

Augmentation of T Cell Levels and Responses Induced by Androgen Deprivation

Androgen has been implicated as a negative regulator of host immune function and a factor contributing to the gender dimorphism of autoimmunity. Conversely, androgen deprivation has been suggested to potentiate male host immunity. Studies have shown that removal of androgen in postpubertal male mice produces an increase in size and cellularity of primary and peripheral lymphoid organs, and enhances a variety of immune responses. Yet, few details are known about the effect of androgen removal on T cell-mediated immunity. In this study, we demonstrate two pronounced and independent alterations in T cell immunity that occur in response to androgen deprivation, provided by castration, in postpubertal male mice. First, we show that levels of T cells in peripheral lymphoid tissues of mice are increased by androgen deprivation. Second, T cells from these mice transiently proliferate more vigorously to TCR- and CD28-mediated costimulation as well as to Ag-specific activation. In addition, androgen deprivation accelerates normalization of host T and B cell levels following chemotherapy-induced lymphocyte depletion. Such alterations induced by androgen deprivation may have implications for enhancing immune responses to immunotherapy and for accelerating the recovery of the immune system following chemotherapy.

A Prospective, Multi-institutional, Pathologist-Based Assessment of 4 Immunohistochemistry Assays for PD-L1 Expression in Non–Small Cell Lung Cancer

Importance Four assays registered with the US Food and Drug Administration (FDA) detect programmed cell death ligand 1 (PD-L1) to enrich for patient response to anti–programmed cell death 1 and anti–PD-L1 therapies. The tests use 4 separate PD-L1 antibodies on 2 separate staining platforms and have their own scoring systems, which raises questions about their similarity and the potential interchangeability of the tests. Objective To compare the performance of 4 PD-L1 platforms, including 2 FDA-cleared assays, 1 test for investigational use only, and 1 laboratory-developed test. Design, Setting, and Participants Four serial histologic sections from 90 archival non–small cell lung cancers from January 1, 2008, to December 31, 2010, were distributed to 3 sites that performed the following immunohistochemical assays: 28-8 antibody on the Dako Link 48 platform, 22c3 antibody on the Dako Link 48 platform, SP142 antibody on the Ventana Benchmark platform, and E1L3N antibody on the Leica Bond platform. The slides were scanned and scored by 13 pathologists who estimated the percentage of malignant and immune cells expressing PD-L1. Statistical analyses were performed from December 1, 2015, to August 30, 2016, to compare antibodies and pathologists’ scoring of tumor and immune cells. Main Outcomes and Measures Percentages of malignant and immune cells expressing PD-L1. Results Among the 90 samples, the SP142 assay was an outlier, with a significantly lower mean score of PD-L1 expression in both tumor and immune cells (tumor cells: 22c3, 2.96; 28-8, 3.26; SP142, 1.99; E1L3N, 3.20; overall mean, 2.85; and immune cells: 22c3, 2.15; 28-8, 2.28; SP142, 1.62; E1L3N, 2.28; overall mean, 2.08). Pairwise comparisons showed that the scores from the 28-8 and E1L3N tests were not significantly different but that the 22c3 test showed a slight (mean difference, 0.24-0.30) but statistically significant reduction in labeling of PD-L1 expression in tumor cells. Evaluation of intraclass correlation coefficients (ICCs) between antibodies to quantify interassay variability for PD-L1 expression in tumor cells showed high concordance between antibodies for tumor cell scoring (0.813; 95% CI, 0.815-0.839) and lower levels of concordance for immune cell scoring (0.277; 95% CI, 0.222-0.334). When examining variability between pathologists for any single assay, the concordance between pathologists’ scoring for PD-L1 expression in tumor cells ranged from ICCs of 0.832 (95% CI, 0.820-0.844) to 0.882 (95% CI, 0.873-0.891) for each assay, while the ICCs from immune cells for each assay ranged from 0.172 (95% CI, 0.156-0.189) to 0.229 (95% CI, 0.211-0.248). Conclusions and Relevance The assay using the SP142 antibody is an outlier that detected significantly less PD-L1 expression in tumor cells and immune cells. The assay for antibody 22c3 showed slight yet statistically significantly lower staining than either 28-8 or E1L3N, but this significance was detected only when using the mean of 13 pathologists’ scores. The pathologists showed excellent concordance when scoring tumor cells stained with any antibody but poor concordance for scoring immune cells stained with any antibody. Thus, for tumor cell assessment of PD-L1, 3 of the 4 tests are concordant and reproducible as read by pathologists.

Seroma-associated primary anaplastic large-cell lymphoma adjacent to breast implants: an indolent T-cell lymphoproliferative disorder.

Non-Hodgkin lymphomas of the breast are rare, encompassing approximately 0.04–0.5% of all malignant breast tumors, and the vast majority are B-cell lymphomas. In contrast, lymphomas of T-cell phenotype have been rarely reported and some of these have been in close proximity to a breast implant. In our consultation practice, we have identified four patients with primary T-cell anaplastic large-cell lymphoma presenting adjacent to silicone or saline breast implants. All patients presented with seroma and neoplastic cells were identified in suspension in the serous fluid without solid tissue invasion. Three patients had no evidence of systemic disease (stage 1E), and one patient was not staged. The mean age of the patients was 46 years (range, 34–59 years). In all patients, the neoplastic cells had a T-cell phenotype, expressed CD30, cytotoxic granule-associated proteins, EMA and clusterin, and were anaplastic lymphoma kinase-1-negative. Clonal T-cell receptor γ-chain gene rearrangements were identified in three patients. All patients underwent capsulectomy with removal of the implant. One patient subsequently received chemotherapy and radiation therapy, and another was treated with radiation alone. The third patient received no further therapy and the fourth patient has been recently diagnosed. After a mean time of 13 months (range, 9–20 months), all three patients with follow-up were alive and well without any recurrence or systemic disease. Although the follow-up time was relatively short, our series and other reported cases suggest that primary anaplastic large-cell lymphoma adjacent to breast implants is an indolent T-cell lymphoproliferative disorder.

B7-H1 Expression in Malignant Pleural Mesothelioma is Associated with Sarcomatoid Histology and Poor Prognosis

Introduction: B7 homolog 1 (B7-H1; aka programmed cell death 1 ligand 1) is a negative costimulatory molecule that is associated with poor prognosis in many tumor types. Given the poor prognosis and the limited treatments available for mesothelioma, we decided to examine B7-H1 expression and its association with survival in patients with mesothelioma. Methods: Expression of B7-H1 was determined in 106 patients using a mouse monoclonal antihuman B7-H1 (clone 5H1-A3) antibody with immunohistochemistry. Positive expression was defined as ≥5% positively stained cells. Clinicopathologic features and survival were compared between B7-H1-positive and B7-H1-negative groups. Results: Malignant mesotheliomas of 42 patients (40%) expressed B7-H1. Patients with B7-H1-postive tumors were less likely to be offered or undergo therapeutic surgery (p = 0.03). All sarcomatoid mesotheliomas except one desmoplastic subtype expressed B7-H1. Survival was significantly decreased for patients whose tumors expressed B7-H1 (5 months median, 2–9.5 months interquartile range) compared with those whose tumors did not (14.5 months, 9.25–19 months; p < 0.0001). In a multivariate model, B7-H1 expression and sarcomatoid mesothelioma remained significantly associated with worse survival (risk ratio 1.71, 95% confidence interval 1.03–2.78 [p = 0.04] and risk ratio 2.18, 1.08–4.23 [p = 0.03], respectively). Conclusions: B7-H1 is expressed in a substantial proportion of malignant pleural mesotheliomas and is associated with poor survival. Almost all malignant pleural mesotheliomas with sarcomatoid differentiation expressed B7-H1. The expression of B7-H1 may have important therapeutic implications for the management of malignant pleural mesothelioma.

BRAF V600E expression in Langerhans cell histiocytosis: clinical and immunohistochemical study on 25 pulmonary and 54 extrapulmonary cases.

Pulmonary Langerhans cell histiocytosis (PLCH) has been postulated to be a smoking-related non-neoplastic condition, distinct from extrapulmonary LCH, which is generally regarded as a clonal, neoplastic process. Recent genomic studies demonstrated BRAF V600E mutation in 38% to 57% of extrapulmonary LCH cases by polymerase chain reaction. We evaluated the BRAF V600E expression by immunohistochemistry (IHC) in PLCH and extrapulmonary LCH cases. We compared BRAF V600E expression in PLCH and extrapulmonary LCH with BRAF V600E mutation status. Our study included 25 PLCH (age 42.0±11.4, 10 men) and 54 extrapulmonary LCH (age 27.6±21.8, 37 men) cases. Seven of 25 (28%) PLCH cases were positive for BRAF V600E expression (age 45.3±8.1, 2 men); 6 of 7 cases with BRAF V600E expression were also positive by mutation analysis. Nineteen of 54 (35%) extrapulmonary LCH cases were positive for BRAF V600E expression (age 27.6±22.1, 13 men) as well as mutation. Two IHC-negative cases, however, were positive by mutation analysis. All PLCH cases were current or former smokers, whereas 28 of 54 extrapulmonary LCH patients were never-smokers. The cumulative tobacco exposure at the time of diagnosis was significantly higher in BRAF V600E-positive than in BRAF V600E-negative PLCH patients (mean pack-years 48.3 vs. 23.7, 2-tailed t test P=0.01). BRAF V600E expression by IHC correlated with BRAF V600E mutational status in most of the cases in our study except in 3 patients (4.4%). In conclusion, a subset of PLCH with BRAF V600E expression may be a clonal proliferative process, in which cigarette smoking might play a role.

Immunophenotypic attributes of benign peripheral blood γδ T cells and conditions associated with their increase

CONTEXT In comparison to alphabeta T cells, little is known about the immunophenotype of healthy peripheral blood gammadelta T cells or about conditions associated with expansion of this usually minor T-cell subset. OBJECTIVE To study the immunophenotype of increased nonneoplastic peripheral blood gammadelta T cells and to determine clinical conditions associated with this laboratory finding. DESIGN Flow cytometric T-cell phenotyping studies performed on 352 consecutive peripheral blood specimens were reviewed, and 62 cases (18%) in which gammadelta T cells comprised either more than 5% of the total lymphocytes or had an absolute count of more than 200 cells per muL or both, were studied further. Clinical data were available from 36 cases. RESULTS The gammadelta T cells often had an immunophenotype distinct from the alphabeta T cells, with differences in CD5 expression as the most common (n = 17), followed by differences in CD3 (n = 6) and CD7 (n = 3). CD16 coexpression by the gammadelta T cells was also frequent (n = 20). In 28 (78%) of 36 cases, there were one or more associated conditions: infection/inflammatory disease (n = 18), autoimmune disease (n = 9), lymphoproliferative disorder (n = 6), and splenectomy (n = 3). CONCLUSIONS Circulating gammadelta T cells are immunophenotypically distinct from alphabeta T cells, and mild increases in these cells are not uncommon and may be associated with immune system activation and splenectomy. Recognition of this phenomenon is important because reactive gammadelta T cells can exhibit distinctive immunophenotypic features that are also encountered in neoplastic conditions, such as T-cell large granular lymphocytic leukemia.

Histopathologic, immunophenotypic and cytogenetic features of pulmonary mucoepidermoid carcinoma

Pulmonary mucoepidermoid carcinoma is an uncommon but distinctive manifestation of mucoepidermoid carcinoma. Pulmonary mucoepidermoid carcinoma occurs in adults and children and can cause diagnostic problems, especially in small biopsies. Few studies have characterized the histologic and immunophenotypic features of pulmonary mucoepidermoid carcinoma. t(11;19)(q21;p13) is considered disease-defining for mucoepidermoid carcinoma; its significance in pulmonary mucoepidermoid carcinoma warrants further study. Forty three pulmonary mucoepidermoid carcinomas were re-reviewed and graded according to the Brandwein grading system for mucoepidermoid carcinoma. Four cases were excluded because of a split opinion between pathology report and re-review. These cases were negative for MAML2 rearrangement by FISH. TTF-1, napsin A, p40 and p63 immunostains were scored: 0 (negative), 1 (1–25% tumor cells), 2 (26–50%), 3 (51–75%) or 4 (>75%). FISH to detect MAML2 rearrangement used a MAML2-11q21 break-apart probe. Thirty nine pulmonary mucoepidermoid carcinoma (4 low, 30 intermediate, 5 high grade) contained mucous, epidermoid and intermediate cells and lacked keratinization and in situ carcinoma of the overlying epithelium. All cases with available gross description (n=22) had a central/endo- or peribronchial location. All 25 cases tested for immunohistochemistry were positive (scores 1–4) for p63; 23 also expressed p40. In six cases, the p63 score was higher than p40. TTF-1 and napsin were uniformly negative in all 25 cases. MAML2 rearrangement was identified by FISH in each of the 24 cases tested (3 low, 19 intermediate, 2 high grade). Clinical history was available in 29 patients (15 men) (median age, 48 years) with follow-up in 24 (median, 8.4 years). Five patients died of unrelated causes; one developed metastatic pulmonary mucoepidermoid carcinoma. In conclusion, features helpful in distinguishing pulmonary mucoepidermoid carcinoma from other lung cancers include its central/endo- or peribronchial location together with the presence of mucous cells, p63 expression, lack of keratinization and MAML2 rearrangement. TTF-1 and napsin are typically not expressed.

MicroRNA-mRNA interactions in a murine model of hyperoxia-induced bronchopulmonary dysplasia

BackgroundBronchopulmonary dysplasia is a chronic lung disease of premature neonates characterized by arrested pulmonary alveolar development. There is increasing evidence that microRNAs (miRNAs) regulate translation of messenger RNAs (mRNAs) during lung organogenesis. The potential role of miRNAs in the pathogenesis of BPD is unclear.ResultsFollowing exposure of neonatal mice to 80% O2 or room air (RA) for either 14 or 29 days, lungs of hyperoxic mice displayed histological changes consistent with BPD. Comprehensive miRNA and mRNA profiling was performed using lung tissue from both O2 and RA treated mice, identifying a number of dynamically regulated miRNAs and associated mRNA target genes. Gene ontology enrichment and pathway analysis revealed that hyperoxia modulated genes involved in a variety of lung developmental processes, including cell cycle, cell adhesion, mobility and taxis, inflammation, and angiogenesis. MiR-29 was prominently increased in the lungs of hyperoxic mice, and several predicted mRNA targets of miR-29 were validated with real-time PCR, western blotting and immunohistochemistry. Direct miR-29 targets were further validated in vitro using bronchoalveolar stem cells.ConclusionIn newborn mice, prolonged hyperoxia induces an arrest of alveolar development similar to that seen in human neonates with BPD. This abnormal lung development is accompanied by significant increases in the levels of multiple miRNAs and corresponding decreases in the levels of predicted mRNA targets, many of which have known or suspected roles in pathways altered in BPD. These data support the hypothesis that dynamic regulation of miRNAs plays a prominent role in the pathophysiology of BPD.

Transbronchial Cryobiopsy in Diffuse Parenchymal Lung Disease: Retrospective Analysis of 74 Cases

Background: Diagnostic evaluation of patients with diffuse parenchymal lung disease (DPLD) is best achieved by a multidisciplinary team correlating clinical, radiological, and pathologic features. Surgical lung biopsy remains the gold standard for histopathologic diagnosis of idiopathic interstitial pneumonias. Emerging data suggest an increasing role for transbronchial cryobiopsy (TBC) in DPLD evaluation. We describe our experience with TBC in patients with DPLD. Methods: We retrospectively reviewed medical records of patients with radiographic features of DPLD who underwent TBC at Mayo Clinic in Rochester, Minnesota from June 2013 to September 2015. Results: Seventy‐four patients (33 women [45%]) with a mean age of 63 years (SD, 13.8) were included. The mean maximal diameter of the samples was 9.2 mm (range, 2–20 mm [SD, 3.9]). The median number of samples per procedure was three (range, one to seven). Diagnostic yield was 51% (38 of 74 specimens). The most frequent histopathologic patterns were granulomatous inflammation (12 patients) and organizing pneumonia (OP) (11 patients), resulting in the final diagnoses of hypersensitivity pneumonitis (six patients), cryptogenic OP (six patients), connective tissue disease‐associated OP (three patients), drug toxicity (three patients), infection‐related OP (two patients), sarcoidosis (two patients), and aspiration (one patient). Other histopathologic patterns included respiratory bronchiolitis (three patients), acute fibrinous and organizing pneumonia (two patients), desquamative interstitial pneumonia (1 patient), diffuse alveolar damage (one patient), pulmonary alveolar proteinosis (one patient), amyloidosis (one patient), eosinophilic pneumonia (one patient), necrotizing vasculitis (one patient), bronchiolitis with food particles (one patient), and malignancy (three patients). Pneumothorax developed in one patient (1.4%), and bleeding occurred in 16 patients (22%). Conclusions: Our single‐center cohort demonstrated a 51% diagnostic yield from TBC; the rates of pneumothorax and bleeding were 1.4% and 22%, respectively. The optimal use of TBC needs to be determined.