Eliana Gilioli

True 3q Chromosomal Amplification in Squamous Cell Lung Carcinoma by FISH and aCGH Molecular Analysis: Impact on Targeted Drugs

Squamous lung carcinoma lacks specific “ad hoc” therapies. Amplification of chromosome 3q is the most common genomic aberration and this region harbours genes having role as novel targets for therapeutics. There is no standard definition on how to score and report 3q amplification. False versus true 3q chromosomal amplification in squamous cell lung carcinoma may have tremendous impact on trials involving drugs which target DNA zones mapping on 3q. Forty squamous lung carcinomas were analyzed by FISH to assess chromosome 3q amplification. aCGH was performed as gold-standard to avoid false positive amplifications. Three clustered patterns of fluorescent signals were observed. Eight cases out of 40 (20%) showed ≥8 3q signals. Twenty out of 40 (50%) showed from 3 to 7 signals. The remaining showed two fluorescent signals (30%). When corrected by whole chromosome 3 signals, only cases with ≥8 signals maintained a LSI 3q/CEP3 ratio >2. Only the cases showing 3q amplification by aCGH (+3q25.3−3q27.3) showed ≥8 fluorescent signals at FISH evidencing a 3q/3 ratio >2. The remaining cases showed flat genomic portrait at aCGH on chromosome 3. We concluded that: 1) absolute copy number of 3q chromosomal region may harbour false positive interpretation of 3q amplification in squamous cell carcinoma; 2) a case results truly “amplified for chromosome 3q” when showing ≥8 fluorescent 3q signals; 3) trials involving drugs targeting loci on chromosome 3q in squamous lung carcinoma therapy have to consider false versus true 3q chromosomal amplification.

ALK/EML4 Fusion Gene May Be Found in Pure Squamous Carcinoma of the Lung

Introduction: The report of cases of lung squamous cell cancers harboring anaplastic lymphoma kinase (ALK) gene rearrangements raises the question whether this histologic subtype should be also evaluated for such molecular predictive test. Methods: A consecutive series of 40 lung pure squamous cell carcinomas were analyzed for ALK gene status by fluorescence in situ hybridization. Squamous differentiation was validated using an immunohistochemical panel including n-p63 (p40), cytokeratin (CK) 5/6, sex-determining region Y (SRY)-Box2 (SOX2), thyroid transcription factor 1, CK7, and Napsin-A. Results: Squamous differentiation was confirmed in all tumors as they stained positive for n-p63 and CK5/6 and negative for thyroid transcription factor 1 and Napsin-A. One of 40 cases (2.5%) showed an ALK rearrangement on fluorescence in situ hybridization analysis. Conclusions: ALK translocation may be found in lung pure squamous cell carcinomas. Our data suggest the opportunity to test ALK rearrangements on biopsy samples harboring squamous cell cancer differentiation.

Pulmonary Adenocarcinoma With Enteric Differentiation: Immunohistochemistry and Molecular Morphology

Pulmonary adenocarcinoma with enteric differentiation (PAED) is a rare subtype of lung adenocarcinoma recently recognized in the WHO classification. It is defined as an adenocarcinoma in which the enteric component exceeds 50% and have to show the expression of at least 1 immunohistochemical marker of enteric differentiation. Although the definition of this tumor type is very important, above all in the differential diagnosis between a primary lung tumor and a metastasis of colorectal adenocarcinoma, this cancer still lacks a distinctive immunohistochemical and molecular signature. We recruited the largest series in the literature of PAEDs according to the morphology and the positivity for intestinal markers. Then, we evaluated the immunohistochemical and molecular profile of these adenocarcinomas. In our series, CDX-2 and CK7 were the immunohistochemical markers mostly expressed by PAEDs. There was an inverse relationship between the expression of pnuemocytes markers, such as TTF-1, and intestinal markers. Molecular analysis revealed KRAS as the most frequently mutated gene (>60% of cases), with very few cases harboring abnormalities affecting EGFR, BRAF, and ALK genes. PAEDs are morphologically very heterogenous. The immunohistochemical profile based on CDX-2 and CK7 positivity of PAEDs appears very robust to support this diagnosis, and it is applicable also on small biopsies. KRAS appears as the most important mutated gene in such tumors.

Immunohistochemical differentiation of follicular lymphoma from florid reactive follicular hyperplasia with monoclonal antibodies reactive on paraffin sections

In this study monoclonal antibodies which recognize lymphoid‐associated antigens on paraffin sections (LN1, MB2, L26, MT2, UCHL1) have been evaluated to assess their usefulness in the distinction between reactive and neoplastic lesions of lymphoid follicles. Thirty‐three follicular lymphoma samples and 36 reactive samples (lymph nodes and tonsils) were analyzed. MT2 appeared as the most valuable immunophenotypic marker as emerged from a comprehensive quantitative evaluation of 2329 reactive follicles and 2288 neoplastic follicles performed on MT2 immunostained sections. MT2‐positive follicles were found in all lymphoma samples but one. Overall 1908 of 2288 neoplastic follicles were judged as positive whereas no follicles with comparable strong MT2 immunoreactivity could be found in non neoplastic samples. These latter showed weak MT2 positivity only in about 10% (224/2329) of reactive follicles. This study confirms that MT2 follicular positivity can be considered a reliable marker of follicular neoplasia, although negative results ought to be considered with caution. The detection of centrofollicular cells outside the germinal centers, which is considered a reliable criterion of follicular neoplasia, was highly improved by LN1 immunostaining. On the other hand pan‐B antibodies such as L26 and MB2 were less informative because of the large number of B‐lymphocytes observed in interfollicular areas of nonneoplastic samples.

Epithelial to mesenchymal transition-related proteins ZEB1, β -catenin, and β -tubulin-III in idiopathic pulmonary fibrosis

Epithelial to mesenchymal transition has been suggested as a relevant contributor to pulmonary fibrosis, but how and where this complex process is triggered in idiopathic pulmonary fibrosis is not fully understood. Beta-tubulin-III (Tubβ3), ZEB1, and β-catenin are partially under the negative control of miR-200, a family of micro-RNAs playing a major role in epithelial to mesenchymal transition, that are reduced in experimental lung fibrosis and idiopathic pulmonary fibrosis. We wonder whether in situ expression of these proteins is increased in idiopathic pulmonary fibrosis, to better understand the significance of miR-200 feedback loop and epithelial to mesenchymal transition. We investigated the immunohistochemical and immunofluorescent expression and precise location of ZEB1, Tubβ3, and β-catenin in tissue samples from 34 idiopathic pulmonary fibrosis cases and 21 controls (5 normal lungs and 16 other interstitial lung diseases). In 100% idiopathic pulmonary fibrosis samples, the three proteins were concurrently expressed in fibroblastic foci, as well in damaged epithelial cells overlying these lesions and in pericytes within neo-angiogenesis areas. These results were also confirmed by immunofluorescence assay. In controls the abnormal expression of the three proteins was absent or limited. This is the first study that relates concurrent expression of Tubβ3, ZEB1, and β-catenin to abnormal epithelial and myofibroblast differentiation in idiopathic pulmonary fibrosis, providing indirect but robust evidence of miR-200 deregulation and epithelial to mesenchymal transition activation in idiopathic pulmonary fibrosis. The abnormal expression and localization of these proteins in bronchiolar fibro-proliferative lesions are unique for idiopathic pulmonary fibrosis, and might represent a disease-specific marker in challenging lung biopsies.

Increased Frequency of Bronchiolar Histotypes in Lung Carcinomas Associated with Idiopathic Pulmonary Fibrosis

The association between lung cancer and idiopathic pulmonary fibrosis (IPF) is well known, but the significance of this association is poorly understood. Bronchiolar honeycomb cysts have been proposed as possible precursors for the development of carcinoma, but limited evidence in support of this hypothesis is available. The aim of this study was to investigate this hypothesis analysing a series of carcinomas arising in IPF by immunohistochemistry.

Primary bi-atrial Burkitt lymphoma with severe inflow impairment in an immunocompetent patient

We report herein a case of sporadic primary cardiac bi-atrial Burkitt lymphoma (BL) occurred in a 67-year-old white immunocompetent patient and presenting with signs and symptoms of severe bilateral atrioventricular inflow impairment. Extranodal BL involving the heart is rare and seldom recognized clinically. Delayed discovery contributes to significant mortality. In the case presented extended surgical excision and intensive combination chemotherapy regiments resulted in complete remission at 1 year.

Mesothelial/monocytic incidental cardiac excrescences (MICE): report of a case and review of literature with focus on pathogenesis

Mesothelial/monocytic incidental cardiac excrescence (MICE) is a benign lesion composed of histiocytes and mesothelial cells, usually found during cardiac surgery. To date, no more than 50 cases are reported in literature, and pathogenesis is still unclear even if different theories have been proposed. Here we report a case of MICE encountered during aortic valve replacement with typical histological features and extensive immunohistochemical investigation. To date, little information is available about the pathogenesis of MICE. We review the current literature focusing on the role of adhesion molecules such as CD31.

ALK gene copy number in lung cancer: Unspecific polyploidy versus specific amplification visible as double minutes

BACKGROUND Gains of a gene due to DNA polyploidy versus amplification of the specific locus are distinct molecular alterations in tumors. OBJECTIVE We quantified copy number gains of ALK gene due to unspecific polyploidy versus amplifications of the specific locus in a series of non-small cell lung cancers. METHODS The locus specific ALK copy (LSI) number status was evaluated in 205 cases by FISH. Ratio LSI ALK copy number corrected for control probes CEP2, CEP3 and CEP17 (CEPs) was scored. Amplification of the specific ALK locus was defined when ratio set to ≥ 2 while polyploidy was interpreted when the increase in gene copy resulted < 2 in ratio (LSI/control CEPs). RESULTS Twenty one cases (10.2%) showed ≥ 8 ALK signals, 68 cases (33.2%) 3-7 signals and 116 cases (56.6%) a mean of 2 signals. Only 2/21 cases of the cohort harboring ≥ 8 signals showed a ratio ≥ 2 after CEPs correction interpretable as amplified, showing numerous doubled fluorescent spots. All the remaining cases showed a mirrored number of fluorescent spots per each CEPs, interpretable as polyploidy. CONCLUSION We detected a high prevalence of ALK gene copy number usually due to polyploidy rather than ALK locus amplification, the latter visible prevalently as double minutes.