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Malignant pleural effusion (MPE) presents a severe medical condition in patients with advanced breast cancer (BC). We applied organoid culture technology to culture preoperative puncture specimen and corresponding surgical specimen-derived tumor cells from early BC patients and pleural effusion-derived tumor cells from advanced BC patients with MPE to study whether in vitro models could predict therapies of clinical patients. We successfully expanded pleural effusion-derived tumor organoids from 1 advanced triple-negative breast cancer (TNBC) patient with MPE which had been continuously propagated for more than 3 months. The organoids matched the histological characteristics of primary BC and metastatic supraclavicular lymph nodes by H&E staining and retained negative expression of TNBC biomarkers: estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, and positive expression of antigen Ki-67. Multiple mutations were detected from this advanced TNBC patient with MPE by high-throughput sequencing of metastatic supraclavicular lymph node and the plasma sample. We performed the 3D drug screening tests combined with the clinical medication situation of this patient. The pleural effusion-derived tumor organoids were sensitive to capecitabine (IC 50 1.580 μmol) and everolimus (IC 50 4.008 μmol) single-agent treatments. The sensitivity to capecitabine was consistent with the clinical treatment response of this patient for capecitabine and with the sequencing results that reported MTHFR gene polymorphism mutation and TYMS -6bp/-6bp polymorphism mutation indicating effectiveness to fluorouracil. Our results suggested that an effective platform for ex vivo pleural effusion-derived tumor organoids from advanced TNBC patients with MPE could be used to identify treatment options and explore the clinicopathological characteristics of these patients.

Background: Pleural fluid can be used to assess targetable mutations in patients with lung adenocarcinoma. The primary objective of this study was to assess the yield of pleural fluid cytology for targetable oncogenic mutations (EGFR, KRAS, BRAF, ALK, and ROS1 gene rearrangements). We also assessed pleural fluid volume necessary for molecular testing., Methods: Retrospective review was performed of 134 consecutive patients with lung adenocarcinoma associated malignant pleural effusions. EGFR and KRAS testing was done using PCR amplification followed by DNA sequencing, or next generation sequencing in more recent cases that included BRAF assessment. Fluorescence in situ hybridization employing break-apart probes was used to test for ALK and ROS1 rearrangements., Results: Mutation analysis on pleural fluid cell-block was performed on 56 patients. It was adequate for complete analysis ordered including EGFR, KRAS, BRAF, ALK, and ROS1 rearrangements on 40 (71.4%) samples. For individual mutations, EGFR testing was possible in 38 of 49 (77.6%); KRAS 22 of 28 (78.6%); BRAF 10 of 13 (76.9%), ALK gene rearrangement 42 of 51 (82.4%) and ROS1 gene rearrangement in 21 of 28 (75%) pleural fluid specimens. The analysis was satisfactory in 13 of 19 (68.4%) samples with ≤100 mL versus 27 of 37 (72.9%) with >100 mL of fluid tested (P-value=0.7)., Conclusion: Genetic mutation analysis can be performed on malignant pleural effusions secondary to lung adenocarcinoma, independent of fluid volume.

Background: Haematological malignancy is an important cause of pleural effusion. Pleural effusions secondary to haematological malignancy are usually lymphocyte predominant. However, several other conditions such as carcinoma, tuberculosis, and chronic heart failure also cause lymphocytic effusions. Lymphocyte subset (LS) analysis may be a useful test to identify haematological malignancy in patients with lymphocytic effusions. However, research into their utility in pleural effusion diagnostic algorithms has not yet been published., Objectives: We aimed to determine the clinical utility of pleural fluid LS analysis and whether it can be applied to a diagnostic algorithm to identify effusions secondary to haematological malignancy. The secondary aim was to evaluate the diagnostic value of pleural fluid differential cell count., Methods: Consecutive consenting patients presenting to our pleural service between 2008 and 2013 underwent thoracentesis and differential cell count analysis. We proposed an algorithm which selected patients with lymphocytic effusions (>50%) to have further fluid sent for LS analysis. Two independent consultants agreed on the cause of the original effusion after a 12-month follow-up period., Results: A total of 60 patients had samples sent for LS analysis. LS analysis had an 80% sensitivity (8/10) and a 100% specificity for the diagnosis of haematological malignancy. The positive and negative predictive values were 100 and 96.1%, respectively. Overall 344 differential cell counts were analysed; 16% of pleural effusions with a malignant aetiology were neutrophilic or eosinophilic at presentation. A higher neutrophil and eosinophil count was associated with benign diagnoses, whereas a higher lymphocyte count was associated with malignant diagnoses., Conclusions: LS analysis may identify haematological malignancy in a specific cohort of patients with undiagnosed pleural effusions. A pleural fluid differential cell count provides useful additional information to streamline patient pathway decisions., (© 2017 S. Karger AG, Basel.)

Background: Tumor-derived autophagosome vaccines (DRibbles) have the potential to broaden immune response to poorly immunogenic tumors., Methods: Autologous vaccine generated from tumor cells harvested from pleural effusions was administered to patients with advanced NSCLC with the objectives of assessing safety and immune response. Four patients were vaccinated and evaluable for immune response; each received two to four doses of vaccine. Study therapy included two cycles of docetaxel 75 mg/m 2 on days 1 and 29 to treat the tumor, release hidden antigens and produce lymphopenia. DRibbles were to be administered intradermally on days 14, 43, 57, 71, and 85, together with GM-CSF (50 μg/d x 6d, administered via SQ mini pump). Peripheral blood was tested for immune parameters at baseline and at each vaccination., Results: Three of four patients had tumor cells available for testing. Autologous tumor-specific immune response was seen in two of the three, manifested by IL-5 (1 patient after 3 doses), and IFN-γ, TNF-α, IL-5, IL-10 (after 4 doses in one patient). All 4 patients had evidence of specific antibody responses against potential tumor antigens. All patients came off study after 4 or fewer vaccine treatments due to progression of disease. No significant immune toxicities were seen during the course of the study., Conclusions: DRibble vaccine given with GM-CSF appeared safe and capable of inducing an immune response against tumor cells in this small, pilot study. There was no evidence of efficacy in this small poor-prognosis patient population, with treatment not feasible. Trial registration NCT00850785, initial registration date February 23, 2009.

Background: A great individual differences to chemotherapeutic effects existed in the patient with advanced lung cancer. How to choose the optimum regimens to achieve the individuation and maximum effect of chemotherapy for lung cancer is worth exploring. The study was designed to examine the effect of ex vitro chemo-sensitivity assay in xeno-free culture of autologous malignant effusion cells from patients with advanced lung adenocarcinoma., Methods: The 50 treatment-naive patients with lung adenocarcinoma complicated with malignant pleural or pericardial effusions were enrolled. Effusions of all cases had been controlled by closed drainage and 300 mL-500 mL of which were retained under sterile condition from 25 cases (Chemo-sensitivity group). Primary malignant effusion cells were isolated from autologous effusions of the patients. Then, xeno-free culture (average 11 days) were intervened with 8 chemotherapeutic drugs commonly used in clinical practice and were determined by CCK-8 assay. Optimum regimens were selected for chemotherapy based on the results of chemosensitivity test. As a contrast, chemotherapy regimens for the other 25 patients (Control group) were on the basis of physician's clinical experience., Results: After four cycles of chemotherapy, in Chemo-sensitivity group, 17 (68.0%) cases were determined for partial response (PR), 5 (20.0%) cases for stable disease (SD), and the objective response rate (ORR) was 68.0%, the disease control rate (DCR) was 88.0%. Meanwhile, in Control group, 9 (36.0%) cases were determined for PR, 7 (28.0%) cases for SD, and, the ORR was 36.0%, the DCR was 64.0%. There were significant differences between the two groups in ORR and DCR (P<0.05). To the end of follow-up, there were 21 cases of death in Chemo-sensitivity group as well as 22 cases in Control group. The mean progression-free survival (PFS) in Chemo-sensitivity group and Control group respectively were 10.0 months and 5.8 months, and the mean overall survival (OS) in the two groups were 30.2 months and 21.2 months respectively. There were also significant differences between the two groups in PFS and OS (P<0.05). Furthermore, the adverse reactions in both groups were mild and controllable., Conclusions: Xeno-free culture of autologous malignant effusion cells from patients with advanced lung adenocarcinoma and ex vitro chemo-sensitivity assay are beneficial to the rational choices of chemotherapeutic agents used in patients with lung adenocarcinoma complicated with malignant effusions, which is a worthy trial in personalized cell culture for individualized cancer therapy and further studies.

We describe cases of two previously healthy women presenting with progressively worsening breathlessness for 1-2 months. In both cases, physical examination was suggestive of a left-sided pleural effusion, confirmed by chest X-ray. Analysis of aspirated fluid showed a lymphocytic exudate, but cytological analysis was negative for malignancy in both patients. CT scan revealed malignancies as the underlying cause of the effusions. Both patients were managed with intercostal drainage in order to collect a sufficient amount of pleural fluid to perform a new technique in our hospital: cell block. This proved to be extremely useful in assessing the definitive diagnosis and management of both women. We briefly discuss the approach to a malignant pleural effusion and the aid of this not-so-new technique., (2016 BMJ Publishing Group Ltd.)

Background: In pleural effusion cytology, the distinction of malignant mesothelioma (MM) from reactive mesothelial cells (RMCs) may be challenging, even with the aid of immunocytochemistry or fluorescence in situ hybridization. It has been demonstrated that several microRNAs (miRNAs) are useful for this purpose in cell lines and histologic samples. In the current study, the authors evaluated the utility of an miRNA-based classifier as a complement to cytology., Methods: Quantitative reverse transcriptase-polymerase chain reaction analysis of 15 miRNAs was performed in mesothelial (MET-5A) and MM (H28 and H2052) cell lines. Significant miRNAs were validated in 51 MM and 40 nonneoplastic pleural histologic samples and then were tested in 29 MM and 24 RMC cytologic specimens. The performance of individual and combined miRNAs was assessed for their ability to differentiate between MM and RMCs., Results: MiRNA-19a (MiR-19a), miR-19b, miR-21, miR-25, and miR-126 were differentially expressed in cell lines and histologic samples. MiR-126 was down-regulated in MM surgical specimens compared with nonneoplastic specimens, whereas all of the other miRNAs were overexpressed. In cytologic specimens, all miRNAs except miR-25 were confirmed, exhibiting a sensitivity or a specificity higher than the threshold of 0.80, as recommended by the International Mesothelioma Interest Group. The best classifier resulted from the combination of miR-21 and miR-126, which achieved 0.86 sensitivity and 0.87 specificity., Conclusions: Subject to validation of the current results in further larger studies, miR-21 and miR-126 profiling could be an effective and reliable tool for the diagnosis of MM in pleural effusions complementary to cytology evaluation., (© 2016 American Cancer Society.)

Malignant pleural effusion (MPE ) is due tumor which arises from the mesothelium or metastases from tumor origniating other sites. In large, for undiagnosed unilateral pleural effusions, the most frequent and important diagnosis to be established or excluded is malignancy. Cell block is prepared from residual fluid which is centrifuged or is naturally sedimenting to obtain clots at the bottom of the container. The cell block technique is simple, relatively non-invasive, reproducible and has a high yield for malignant plerual effusion. It plays an important role in the diagnosis, guiding the treatment of maligant pleural effusion. Herein, we summarize the technologys which make the cell block, the differential diagnostic value when multiple sections of the cell block are processed for immunhistochemistry, advantages in the diagnosis of malignant pleural effusion, the clinical value of gene screening in cell block. The aim of this article is to discuss the value of cell block in diagnosis of maligant pleural effusion.

Mesothelioma is a form of cancer generally caused from previous exposure to asbestos. Although it was considered a rare neoplasm in the past, its incidence is increasing worldwide due to extensive use of asbestos. In the current practice of medicine, the gold standard for diagnosing mesothelioma is through a pleural biopsy with subsequent histologic examination of the tissue. The diagnostic tissue should demonstrate the invasion by the tumor and is obtained through thoracoscopy or open thoracotomy, both being highly invasive surgical operations. On the other hand, thoracocentesis, which is removal of effusion fluid from the pleural space, is a far less invasive procedure that can provide material for cytological examination. In this study, we aim at detecting and classifying malignant mesothelioma based on the nuclear chromatin distribution from digital images of mesothelial cells in effusion cytology specimens. Accordingly, a computerized method is developed to determine whether a set of nuclei belonging to a patient is benign or malignant. The quantification of chromatin distribution is performed by using the optimal transport-based linear embedding for segmented nuclei in combination with the modified Fisher discriminant analysis. Classification is then performed through a k-nearest neighborhood approach and a basic voting strategy. Our experiments on 34 different human cases result in 100% accurate predictions computed with blind cross validation. Experimental comparisons also show that the new method can significantly outperform standard numerical feature-type methods in terms of agreement with the clinical diagnosis gold standard. According to our results, we conclude that nuclear structure of mesothelial cells alone may contain enough information to separate malignant mesothelioma from benign mesothelial proliferations., (© 2015 International Society for Advancement of Cytometry.)

Background: Molecular characterisation of non-squamous non-small-cell lung cancer (NSCLC) is required to direct optimal treatment. Treatment of NSCLC with inhibitors of epidermal growth factor receptor (EGFR) tyrosine kinase (EGFR-TKI) should be guided by the presence of activating mutations of the EGFR gene., Aim: To gain insight into the rate of testing, the range of tissues samples, test utility and outcome when cost of testing as a barrier to access is removed in the Australian setting., Methods: In October 2010, a sponsored programme was commenced to gather data on EGFR gene mutation testing in Australia. Partnering laboratories were funded for provision of de-identified results. For participating patients, the programme supported the test charge. Mutation testing was performed using Sanger sequencing of exons 18-21 of the EGFR., Results: Samples 2013 were submitted from 2012 patients. Full sequencing was achieved in 1717 (85%). Failure of full sequencing was more likely in samples derived from fine needle aspiration(FNA) biopsy than tissue biopsy or pleural/pericardial fluid cell blocks OR 3.1 (95% CI 1.9-5.2). There were 359 mutations seen in 337 patients. 14.5% of cases had a classical mutation conferring sensitivity to EGFR-TKI. In addition there was a range of less common mutations - some predicting responses and others of uncertain significance. 1.4% of cases had mutations associated with non-responsiveness to EGFR-TKI., Conclusions: EGFR gene mutation testing is feasible on local and interstate lung cancer samples. The rate of valid test outcomes is high, but FNA samples are associated with more frequent test failure., (© 2014 The Authors; Internal Medicine Journal © 2014 Royal Australasian College of Physicians.)

Background: The cytological analysis of serous effusions is a common investigation and yields important diagnostic information. However, the distinction of reactive mesothelial cells from malignant cells can sometimes be difficult for the cytopathologist. Hence cost-effective ancillary methods are essential to enhance the accuracy of cytological diagnosis. The aim of this study was to examine the utility of nuclear morphometry in differentiating reactive mesothelial cells from malignant cells in effusion smears., Materials and Methods: Sixty effusion smears consisting of 30 effusions cytologically classified as malignant (adenocarcinomas) and 30 benign effusions showing reactive mesothelial cells were included in the study. ImageJ was used to measure the nuclear area, perimeter, maximal feret diameter, minimal feret diameter and the circularity. A total of ten representative cells were studied in each case., Results: Significant differences were found between benign and malignant effusions for the nuclear area, perimeter, maximal feret diameter and minimal feret diameter. No significant difference was found for circularity, a shape descriptor. Receiver operating characteristic (ROC) curve analysis revealed that nuclear area, perimeter, maximal feret diameter, and minimal feret diameter are helpful in discriminating benign and malignant effusions., Conclusions: Computerised nuclear morphometry is a helpful ancillary technique to distinguish benign and malignant effusions. ImageJ is an excellent cost effective tool with potential diagnostic utility in effusion cytology.

Rationale: IL-9-producing CD4(+) T cells (Th9 cells) have been reported to be involved in inflammation and immune diseases. However, the involvement of Th9 cells in malignancy has not been investigated., Objectives: To elucidate the mechanism by which Th9 cells differentiate in malignant pleural effusion (MPE) and to explore the immune regulation of Th9 cells on lung cancer cells., Methods: Distribution of Th9 cells in relation to Th17 and Th1 cells in both MPE and blood were determined. The effects and mechanisms of proinflammatory cytokines and regulatory T cells on differentiation of Th9 cells in vitro were explored. The impacts and signal transductions of IL-9, IL-17, and IFN-γ on lung cancer cell lines were also investigated., Measurements and Main Results: The numbers of Th9, Th17, and Th1 cells were all increased in MPE when compared with blood. The increase in Th9 cells in MPE was due to the promotion by cytokines and regulatory T cells. By activating STAT3 signaling, both IL-9 and IL-17 substantially promoted the proliferation and migratory activity of lung cancer cells, whereas IFN-γ, which activated STAT1 signaling, was noted to suppress lung cancer cell proliferation and migration. IFN-γ could induce lung cancer cell apoptosis. Moreover, IL-9 and IFN-γ, but not IL-17, could strongly facilitate intercellular adhesion of lung cancer cells to pleural mesothelial cell monolayers., Conclusions: Our data revealed that Th9 cells were increased in MPE and that Th9 cells exerted an important immune regulation on lung cancer cells in human tumor environment.

Rationale: IL-5 is a T helper 2 cytokine important in the trafficking and survival of eosinophils. Because eosinophils can be found in malignant pleural effusions (MPE) from mice and humans, we asked whether IL-5 is involved in the pathogenesis of MPE., Objectives: To determine the role of IL-5 in MPE formation., Methods: The effects of IL-5 on experimental MPE induced in C57BL/6 mice by intrapleural injection of syngeneic lung (Lewis lung cancer [LLC]) or colon (MC38) adenocarcinoma cells were determined using wild-type (il5(+/+)) and IL-5-deficient (il5⁻(/)⁻) mice, exogenous administration of recombinant mouse (rm) IL-5, and in vivo antibody-mediated neutralization of endogenous IL-5. The direct effects of rmIL-5 on LLC cell proliferation and gene expression in vitro were determined by substrate reduction and microarray., Measurements and Main Results: Eosinophils and IL-5 were present in human and mouse MPE, but the cytokine was not detected in mouse (LLC) or human (A549) lung and mouse colon (MC38) adenocarcinoma-conditioned medium, suggesting production by host cells in MPE. Compared with il5(+/+) mice, il5⁻(/)⁻ mice showed markedly diminished MPE formation in response to both LLC and MC38 cells. Exogenous IL-5 promoted MPE formation in il5(+/+) and il5⁻(/)⁻ mice, whereas anti-IL-5 antibody treatment limited experimental MPE in il5(+/+) mice. Exogenous IL-5 had no effects on LLC cell proliferation and gene expression; however, IL-5 was found to be responsible for recruitment of eosinophils and tumor-promoting myeloid suppressor cells to MPE in vivo., Conclusions: Host-derived IL-5 promotes experimental MPE and may be involved in the pathogenesis of human MPE.

IL-17-producing CD4(+) T (Th17) cells have been found to be increased in some human cancers; however, the possible implication of Th17 cells in regulating antitumor responses in malignant pleural effusion (MPE) remains to be elucidated. In the current study, distribution and phenotypic features of Th17 cells in both MPE and peripheral blood from patients with lung cancer were determined by flow cytometry or double immunofluorescence staining. The impacts of cytokines on Th17 cell generation and differentiation were explored. The chemoattractant activity of chemokines CCL20 and CCL22 for Th17 cells in vitro was also observed. It was found that the increased Th17 cells could be found in MPE compared with blood. The in vitro experiments showed that IL-1β, IL-6, IL-23, or their various combinations could promote Th17 cell generation and differentiation from naive CD4(+) T cells. MPE was chemotactic for Th17 cells, and this activity was partly blocked by anti-CCL20 and/or CCL22 Abs. Our data also showed that the accumulation of Th17 cells in MPE predicted improved patient survival. It could be concluded that the overrepresentation of Th17 cells in MPE might be due to Th17 cell differentiation and expansion stimulated by pleural proinflammatory cytokines and to recruitment of Th17 cells from peripheral blood induced by pleural chemokines CCL20 and CCL22. Furthermore, the accumulation of Th17 cells in MPE predicted improved patient survival. These data provide the basis for developing immune-boosting strategies based on ridding the cancer patient of this cell population.

A multiple myeloma (MM) cell line, MSG1, which depends on HS23 stromal cells for its survival, was established from the pleural effusion of a patient with MM who expressed the M-protein of IgA-λ in his serum. During the first 2 months of culture, the myeloma cells survived on adhesive cells from the pleural effusion and, subsequently, they continued to proliferate on HS23 stromal cells. The phenotype of the established MSG1 cell line was: CD138(+), CD38(++), CD19⁻, CD56⁻, VLA-4(+), VEGFR1(+) and VEGFR2(+). Immunohistochemical staining also demonstrated expression of the IgA and λ chain in MSG1 cytoplasm. Karyotype analysis indicated complex chromosomal abnormalities; hypertriploidy, including the deletion of chromosomes 13 and 17, and c-myc translocation. MSG1 cells continued to proliferate, not only when co-cultured with HS23 cells, but also when cultured only on fibronectin-coated plates with the supernatant of HS23 cells or with control medium containing IL-6. Tocilizumab, an anti-IL-6 receptor antibody, inhibited MSG1 survival under these conditions. Therefore, MSG1 may be a unique myeloma cell line that is useful for the study of cell adhesion-mediated drug resistance induced by adhesion molecules and IL-6 stimulation of myeloma cells.

Background: Primary effusion lymphoma (PEL) is a highly malignant non-Hodgkin lymphoma associated with Kaposi's sarcoma-associated herpesvirus/human herpesvirus-8 infection (KSHV/HHV-8). It is chiefly seen in HIV patients and is rare in transplant recipients, possibly going unrecognized., Observation: We describe two male kidney transplant recipients, aged 47 and 51 years, followed for Kaposi's sarcoma in skin, lymph nodes, gastrointestinal (GI) tract and lung whose disease was poorly controlled by sirolimus and chemotherapy. Recurrent pleural effusion contrasted with reduction of cutaneous Kaposi lesions. KHSV viral loads were negative or very low in plasma, were negative or very low, whereas those in pleural effusion were high. Lymphoma cells were discovered only seven to nine months after the initial effusion despite repeated needle biopsies. In one patient, tumour cells were co-infected with Epstein-Barr virus., Conclusion: The contrast between a very low KHSV viral load in plasma and a very high viral load pleural effusion should alert physicians and prompt suspicion of PEL in Kaposi's sarcoma patients with recurrent serous effusion. The potential inhibitory role of sirolimus on PEL progression is discussed., (2010 Elsevier Masson SAS. All rights reserved.)

Cytology is the only useful tool in the detection of malignant mesothelioma (MM) at an early stage. No other methods, such as immunocytochemistry or electron microscopy, are available to distinguish MM from reactive mesothelial cells (RMC). Some objective analysis of cytology specimens is necessary. On the basis of our case review and cytological features described in previous articles, we developed a scoring system for malignant mesothelioma (SSMM) of effusion cytology to distinguish MM cells from RMC. Mesothelioma cells in effusions from 22 patients (20 pleural and 2 peritoneal mesotheliomas) were compared with RMC from 20 patients without obvious tumor cells and 50 effusions containing metastatic carcinoma cells. The SSMM is based on characteristic features of mesothelial and malignant cells. The total achievable score is 10 points: one point each is given for variety of cell size, cyanophilic cytoplasm with villosity/windows/bleb, sheet-like arrangement, mirror-ball-like cell clusters, nuclear atypia, and cannibalism, respectively. Further two points each are ascribed for acidophilic large nucleoli and multinucleated cells with more than eight nuclei. The total score for each of the 22 mesotheliomas was more than 5 points. On the other hand, all RMC and the 50 metastatic carcinoma cases scored less than 3 points, aside from two cases that were treated with OK432. No single characteristic feature was observed to be consistent within the 22 mesotheliomas analyzed. Ancillary use of immunocytochemistry, such as podoplanin (D2-40) and calretinin, supported the diagnostic accuracy of the SSMM. SSMM is useful for the differential diagnosis of MM.

We have established a cell line derived from a pleural effusion of breast scirrhous carcinoma. This cell line presented immunohistochemically negative for estrogen receptor and slightly positive for progesterone receptor, and positive for c-erbB/HER2/neu. However the original tumor was found to be positive for estrogen receptor and progesterone receptor and slightly positive for c-erbB/HER2/neu expression. Enzyme and electrochemiluminescence immunoassays of tumor markers in the conditioned medium by the cell line revealed they secrete CA15-3, NCC-ST-439 and HER2 protein. We believe the cell line will contribute to the therapeutic study of malignant breast cancer.

Context: Differentiating reactive effusion, malignant mesothelioma, and metastatic adenocarcinoma in body cavity fluids can be challenging. Interpreting immunohistochemical markers in cell block preparations can be difficult because of nonspecific staining, focal staining, or poor staining quality. We selected a panel of conventional and newer markers to assess their utility in evaluating effusions., Objective: To evaluate the efficacy of 5 immunohistochemical markers in the differential diagnosis of reactive mesothelial proliferation, malignant mesothelioma, and metastatic adenocarcinoma in body cavity fluids., Design: A total of 72 formalin-fixed, paraffin-embedded cell block specimens from pleural and peritoneal effusions, including 5 mesotheliomas, 48 adenocarcinomas, and 19 benign effusions were stained with antibodies against calretinin, D2-40, XIAP, MOC-31, and WT1., Results: All benign effusions and mesotheliomas demonstrated diffuse membranous staining with D2-40. All mesotheliomas displayed calretinin positivity, whereas only 58% of benign effusions stained focally with calretinin. MOC-31 was positive in all cases of adenocarcinoma, whereas all benign effusions and mesotheliomas were negative. All cases of the metastatic adenocarcinoma were negative for calretinin and D2-40. However, background reactive mesothelial cells were positive for calretinin and D2-40. Overall, D2-40 highlighted more mesothelial cells than calretinin. WT1 was positive in 50% of benign effusions, 60% of mesotheliomas, and 27% of adenocarcinomas. XIAP stained most mesotheliomas (80%), some adenocarcinomas (51%), and rare benign effusions (11%)., Conclusions: MOC-31 and D2-40 were very sensitive and specific markers of epithelial and mesothelial cells, respectively. Compared with calretinin, D2-40 was a more sensitive marker of mesothelial cells. WT1 proved to be nonspecific. XIAP was not a sensitive marker for malignancy and had a limited value in cytology. We recommend using a panel to include MOC-31 and D2-40 to improve diagnostic accuracy in body cavity effusions.

Numerous cancer patients fail standard chemotherapy or develop resistance to chemotherapy during the course of treatment. The purpose of this study is to elucidate the overall response of cells obtained from cancer patients and from normal individuals to chemotherapeutic agents. We analysed the chemosensitivity of cancer cells derived from bone marrow and from pleural effusions or ascites fluids from patients with different cancers. Chemosensitivity to doxorubicin, cisplatin and paclitaxel was determined using the MTT assay. We also determined the response of bone marrow mononuclear (BMMN) cells. There was a wide range of responses to chemotherapy drugs in samples from different individuals. This was observed in cells derived from bone marrow and from ascites or pleural fluids. Large variations were also observed among morphologically normal BMMN cells and metastatic cancer cells from chemo-naïve patients. Cancer cells can easily be collected from ascites or pleural fluids and reliably assayed for chemosensitivity. We describe here that inherent chemoresistance may be a reason for the lack of response to chemotherapy in some patients. We discuss the potential of using the determination of natural resistance to dictate the drugs to be employed for treatment.

The objective of this study was to analyze site-related expression of angiogenic molecules in breast carcinoma, with the aim of characterizing phenotypic alterations along the clinical progression from primary tumor to pleural effusion. A total of 49 malignant pleural effusions and 68 corresponding solid tumors were studied for protein and mRNA expression of vascular endothelial growth factor (VEGF) and its receptor KDR, interleukin-8 (IL-8), basic fibroblast growth factor (bFGF) and the alphaV integrin subunit using immunohistochemistry, mRNA in situ hybridization (ISH) and reverse transcription polymerase chain reaction (RT-PCR). Expression was analyzed for possible association with mRNA expression of the Ets-1 and PEA3 transcription factors. The predictive value of angiogenic molecules, PEA3 and Ets-1, and clinical parameters was analyzed for 18 patients. ISH showed the presence of VEGF, IL-8 and bFGF mRNA in the majority of specimens, irrespective of anatomic site (p > 0.05). However, protein expression of IL-8 and bFGF was lower in effusions compared to primary tumors (p = 0.001 for IL-8, p < 0.001 for bFGF). Expression of alphaV integrin showed an opposite change, with higher level in effusions compared to primary tumors (p = 0.03). bFGF and alphaV integrin expression in effusions was also altered compared to lymph node metastases (p = 0.041 and p = 0.016, respectively). IL-8 and Ets-1 (p = 0.035) and VEGF and PEA3 (p = 0.026) mRNA was co-expressed in effusions. In univariate survival analysis, bFGF protein expression in effusions (p = 0.015), PEA3 mRNA expression in primary tumors (p = 0.02) and previous radiation therapy (p = 0.034) predicted shorter disease-free survival. PEA mRNA expression in primary tumors (p = 0.002) and previous chemotherapy (p = 0.048) predicted poor overall survival, with a similar trend for advanced disease stage at diagnosis (p = 0.05). Our data provide evidence regarding molecular changes that occur along the progression of breast carcinoma from primary tumor to effusion, and suggest altered requirement of angiogenic factors in body cavities. The poor disease-free survival for patients with bFGF-positive effusions suggests a role for this growth factor in mediating tumor survival rather than angiogenesis at this site.

Background: The authors conducted a pilot clinical trial to explore the vaccination of patients with late-stage lung carcinoma with dendritic cells (DCs) pulsed with necrotic tumor cells derived from malignant pleural effusion specimens, and to evaluate the antitumor immune response induced by this therapy., Methods: Autologous DCs were generated by culturing adherent mononuclear cells with interleukin-4 and granulocyte-macrophage-colony-stimulating factor for 7 days. Day-7 DCs were cocultured overnight with autologous necrotic tumor cells derived from pleural effusion specimens to allow internalization of tumor antigens. DCs were then treated with tumor necrosis factor-alpha for 16 hours. The antigen-loaded DCs were injected into each patient's inguinal lymph nodes under sonographic guidance. Eight patients with late-stage nonsmall cell lung carcinoma were treated in this manner. Patients were vaccinated once weekly for 4 weeks and then boosted twice biweekly., Results: The authors found that there was no Grade II/III toxicity and autoimmune response in all patients after intranodal injection of the DC vaccine. Minor to moderate increases in T-cell responses against tumor antigens were observed after DC vaccination in six of eight patients. Five patients had progressive disease. One patient had minor tumor response and two patients had stable disease. The two patients who had longer disease control also had better T-cell responses., Conclusions: The results indicated that it was feasible to immunize patients with lung carcinoma intranodally with DCs pulsed with necrotic tumor cells enriched from pleural effusion specimens, and this approach may generate T-cell responses and provide clinical benefit in some patients., (Copyright (c) 2005 American Cancer Society.)

A 4-year-old Oldenburg mare was evaluated because of signs of lower airway disease and subsequently developed bilateral pleural effusion. Neoplastic cells were not identified in the fluid sample obtained via the initial thoracocentesis. A thoracic mass was detected radiographically, but its location prevented collection of a tissue sample. A diagnosis of lymphoma was made on the basis of results of immunophenotyping of pleural fluid specimens. Treatment of thoracic lymphoma in horses has been attempted, but there are limited data regarding chemotherapeutic-induced remission. In this horse, remission was achieved by use of a chemotherapeutic protocol consisting of administration of cytarabine, cyclophosphamide, and prednisolone. No adverse drug reactions were encountered during treatment. Immunophenotyping of cells in specimens of pleural fluid could be used to determine lymphocyte lineage and may be a useful alternative diagnostic modality when morphologic and cytologic examination of tissue specimens obtained via invasive techniques is not feasible.

We report a rare case of isolated pleural hemangioma presenting as recurrent, haemorrhagic pleural effusion. Chest radiograph and computed tomography of chest was suggestive of left apical tumour. Diagnosis of hemangioma was revealed only after thoracotomy and excision of the tumour mass.

A 12-year-old neutered male Shar-Pei was presented to the North Carolina State University Veterinary Teaching Hospital cardiology service with a 2-week history of coughing and a 2-day history of lethargy and anorexia. Pleural effusion and a mediastinal mass were detected with thoracic radiographs. Ten mL of fluid were removed via thoracocentesis, and cytologic examination of the fluid revealed marked eosinophilic inflammation and few atypical mast cells. Mast cell neoplasia was suspected. Aspirates of the mediastinal mass, abdominal lymph nodes, and bone marrow contained similar pleomorphic mast cells and increased numbers of eosinophils. The dog was diagnosed with systemic (visceral) mastocytosis, a rare form of neoplasia in dogs, and was euthanized. These tumors carry a poor to grave prognosis and the etiology is uncertain.

We report a case of a 45-year old woman who was found to have a giant mediastinal tumour with radiological degenerative changes. She underwent thoracotomy to remove the mass, which was eventually diagnosed histologically as an ancient schwannoma, whereas cytological interpretation of the accompanying pleural fluid was malignant. Ancient schwannoma is a rare variant of schwannoma, histologically showing atypical features that may result in erroneous diagnosis of a malignant tumour. Clinical and radiological findings are important aids for further consideration of surgical removal of these potentially resectable tumours.

Study Objectives: To determine the different effects of interleukin (IL)-2, IL-4, IL-7, IL-10, IL-12, and/or T-cell receptor (TCR)-CD3 engagement in recovering the functions of cytotoxic T lymphocytes (CTL) from malignant effusion., Setting: National teaching hospital., Materials and Methods: Effusion-associated lymphocytes (EAL) were isolated from 35 malignant pleural effusions. Interferon (IFN)-gamma production, proliferative response, and cytolytic activity of the cultured EAL against autologous tumors and K-562 cells were measured., Results: It was found that EAL had a significantly depressed function. Stimulation with two signals, including IL-2 plus IL-7, IL-2 plus IL-12, or IL-2 plus TCR-CD3 engagement, could fully restore the functions of EAL, including IFN-gamma production, proliferative response, and a specific increase in cytolytic activity against autologous tumor cells. IL-4 and IL-10, whether or not in combination with IL-2, did not augment the function of EAL, and even depressed it in some cases. The lymphocyte-depletion test showed that most of the recovered functions were from CD8(+) CTL., Conclusion: The depressed cellular function of EAL could be reversed with double signal stimulation, including IL-2 plus IL-7, IL-2 plus IL-12, or IL-2 plus TCR-CD3 engagement. These recovered cellular functions were mainly from CD8(+) CTL.

Background: Exosomes derived from tumours are small vesicles released in vitro by tumour cell lines in culture supernatants. To assess the role of these exosomes in vivo, we examined malignant effusions for their presence. We also investigated whether these exosomes could induce production of tumour-specific T cells when pulsed with dendritic cells., Methods: We isolated exosomes by ultracentrifugation on sucrose and D(2)O gradients of 11 malignant effusions. We characterised exosomes with Western blot analyses, immunoelectron microscopy, and in-vitro stimulations of autologous T lymphocytes., Findings: Malignant effusions accumulate high numbers of membrane vesicles that have a mean diameter of 80 nm (SD 30). These vesicles have antigen-presenting molecules (MHC class-I heat-shock proteins), tetraspanins (CD81), and tumour antigens (Her2/Neu, Mart1, TRP, gp100). These criteria, including their morphological characteristics, indicate the similarities between these vesicles and exosomes. Exosomes from patients with melanoma deliver Mart1 tumour antigens to dendritic cells derived from monocytes (MD-DCs) for cross presentation to clones of cytotoxic T lymphocytes specific to Mart1. In seven of nine patients with cancer, lymphocytes specific to the tumour could be efficiently expanded from peripheral blood cells by pulsing autologous MD-DCs with autologous ascitis exosomes. In one patient tested, we successfully expanded a restricted T-cell repertoire, which could not be recovered carcinomatosis nodules., Interpretation: Exosomes derived from tumours accumulate in ascites from patients with cancer. Ascitis exosomes are a natural and new source of tumour-rejection antigens, opening up new avenues for immunisation against cancers.

The objective of this study was to test the hypothesis that accumulated helper T lymphocytes in malignant pleural effusions may shift to T-helper type 2 (Th2) and produce soluble ST2 protein. We took samples of serum and pleural effusions (p-) from patients with carcinomatous pleurisy (CA, n = 17), tuberculous pleurisy (TB, n = 8), and congestive heart failure (HF, n = 5) and compared the concentration of cytokines or ST2. Ex vivo production of interleukin (IL)-4 and IL-10, though not that of interferon (IFN)-gamma or IL-12, from CD4+ T cells isolated from pleural effusions was higher in the CA group than in the TB or HF group. The p-ST2 concentrations were significantly higher in the CA group than in the TB or HF group, positively correlated with the percentage of pleural effusion CD4+ T cells (r = 0.432, p = 0.016) and inversely correlated with p-IFN-gamma concentrations (r = -0.423, p = 0.019). Furthermore, mRNA expression of ST2 in CD4+ T cells isolated from group CA was upregulated, compared with that in those isolated from the TB group. These results suggest that CD4+ T cells in CA shift to Th2, which can produce soluble ST2 protein, resulting in increased concentrations of p-ST2 in malignant pleural effusion.

The study included 200 patients with pleural effusion. Pleural effusions were transudative in 48 (24%) and exudative in 152 (76%) of cases. Congestive cardiac failure (14.5%), nephrotic syndrome (5.5%), and liver cirrhosis (2.5%) were the most common etiological diagnoses of transudate cases. Malignant effusion (16.5%), pneumonia (13%), pleural empyema (9%), tuberculosis (6%), and pulmonary embolism (5.5%) were the most common etiological diagnoses of exudative cases. Thirty-two (16%) cases of exudative pleural effusions were of undertermined etiology. Polymorphonuclear leucocytes predominated in 48 patients with exudative pleural effusions. The most common etiological diagnoses were pneumonia (41.67%), pleural empyema (39.59%) and pulmonary embolism (10.42%). Lymphocytes in pleural fluid were predominant in 63 patients, with malignant (6.34%), tuberculous pleurisy (19.02%), pulmonary embolism (6.34%), trauma (6.34%), and (46.11%) cases in patients with pleural exudate undertermined etiology. Eosinophyls were predominant in 16 (8%) patients with exudative pleural effusions. The most common etiology of eosinophilic pleural fluid were pneumonia (37.5%), malignant pleural effusion (25%), pulmonary embolism (12.5%), pyopneumothorax (6.25%) and trauma 6.25%. From 16 patients with eosinophilic pleural exudate, in 31% cases air, in 12.5% blood in pleural fluid were determined and in 12.5% cases previous pleural puncture was performed. Pleural fluid eosinophilia is most commonly associated with the presence of air or blood in the pleural fluid (correalation index 0.82). Malignant pleural effusions were determined in 33 patients. Malignant cells in pleural fluid were identified in 25 cases. The diagnostic sensitivity of pleural fluid cytology for malignant pleural effusions were 76%. Hemoragic pleuritis was determined in 18 and hemothorax in 4 patients. Etiology of hemothorax were trauma (75%) and coaguliopathia (25%). Most common etiological diagnoses of hemoragic pleuritis were neoplasia (33.3%), pulmonary embolism (16.65%), trauma (16.65%), pneumonia (11.11%), and congestive cardiac failure (11.11%). Diagnostic sensitivity and specifity of hemoragic pleuritis is low, 58% and 45% respectively.

Background: Cytology plays a pivotal role in the diagnosis of pleural effusions. In many cases, immunocytochemistry (ICC) is required to elucidate the etiology of the atypical cells. Effusions are samples that present unique problems for ICC. To date there is no standardization of ICC methods for effusions and cytology in general., Methods: The authors review the most commonly used cytologic preparations, fixatives, and antibodies used in effusion ICC., Results: Through the utilization of cell block preparations and a panel of antibodies appropriate for the differential diagnosis in question, ICC conditions utilized in surgical pathology can be most closely replicated., Conclusions: ICC may provide reliable insights into various diagnostic dilemmas in effusion cytology, provided that laboratory standardization practices are followed., (Copyright 2001 American Cancer Society.)

Objective: To evaluate the results of computed tomography (CT)-guided fine needle aspiration (FNA) cytology following negative fiberoptic bronchoscopy and sputum cytology., Study Design: Retrospective study of 64 patients who underwent CT-guided needle aspiration of lung opacities over one year. Following a review of the CT studies, patients were selected according to image characteristics of a primary neoplasm and pleural effusion in cases with pleural lesions. The lesions were classified into three categories--intrapulmonary and peripheral pulmonary, pleuropulmonary and pleural--and were localized and aspirated under CT using a fine needle (22-23 gauge) for obtaining cellular material. Lesions diagnosed as benign on FNA cytology were followed by serial CT scans for a period of two years at six-month intervals., Results: Thirty-nine of 64 (61%) lesions were diagnosed as malignant on FNA cytology and 25 of 64 (39%) as benign. There was one false negative case. There were no serious complications from the procedure., Conclusion: FNA under CT guidance may be applied as the initial procedure in the diagnosis of peripheral malignant pulmonary lesions, rendering a high diagnostic yield.

A 57-year-old man was referred and admitted to our hospital because of anterior mediastinal tumors and pericardial effusion. Although his condition had been diagnosed as thymic cancer by another hospital, a cytologic examination of pleural effusion specimens obtained a positive stain for chromogranin A, and yielded a diagnosis of thymic carcinoid tumor with multiple metastases. Despite irradiation and relief therapy, the patient died 8 months later. A histopathologic examination of the thymic tumor at autopsy revealed typical carcinoid patterns. The cytologic examination proved capable of accurately diagnosing the carcinoid tumor. Although such tumors are usually considered to have a good prognosis, unfavorable outcomes are also a possibility, as was demonstrated in this case.

The use of ancillary techniques to aid in the diagnosis of metastatic carcinoma in serous effusions has been the subject of numerous studies. In this article, we study 35 cases of malignant effusions (metastatic adenocarcinoma) and 20 benign effusions using a panel of immunohistochemical markers to determine whether changes in the subpopulations of accompanying lymphoid cells can be detected with this technique and whether such changes are associated with the presence of malignancy. We noted a significant increase in cytotoxic lymphocytes, defined as the percentage of all lymphoid cells staining with an antibody to TIA-1 (an antigen localized to the cytotoxic granule membranes of cytotoxic T cells and natural killer cells) in malignant compared with benign effusions (23% vs. 12%; P < 0.05). In addition, nearly all cases in which cytotoxic lymphocytes composed > 20% of the lymphoid cell population contained metastatic tumor. Thus, immunohistochemical staining for TIA-1 can reliably detect cytotoxic lymphocytes in cell blocks of serous effusions; in addition, a relative increase in their number is associated with the presence of malignancy.

The aim of this study was to assess the biological characteristics of four new malignant mesothelioma (MM) cell lines. Since simian virus (SV)40 sequences have been recently detected in MM, SV40 large T antigen (Tag) expression was also analysed. MM cell lines were characterized by morphological, ultrastructural and cytogenetic analysis. Expression of Tag and of relevant MM markers was studied by immunocytochemistry, surface antigens by indirect immunofluorescence and immunomodulating cytokines by enzyme-linked immunosorbent assay (ELISA). The four MM cell lines, established from pleural effusions, showed a slow proliferation rate and pleomorphic changes during culture. Cell lines expressed vimentin, cytokeratins 8 and 18, and the mesothelial antigen recognized by HBME-1 monoclonal antibody, but not carcinoembryonic antigen. Surface human leukocyte antigen (HLA)-class I and intercellular adhesion molecule (ICAM)-1 molecules were present on all the cell lines. While HLA class II and CD86 were constitutively undetectable, HLA-class II was present after interferon (IFN)-gamma stimulation. All cell lines displayed abnormal karyotypes with chromosome 6 abnormalities. Transforming growth factor (TGF)-beta2 and interleukin (IL)-6 were constitutively secreted, while tumour necrosis factor (TNF)-alpha was secreted only in response to lipopolysaccharide. Intranuclear Tag was expressed in two cell lines. The persistence of large T antigen with human leukocyte antigen class I and intercellular adhesion molecule-1 positivity may point to large T antigen as a target for cytotoxic T-lymphocyte-based immunotherapy in some malignant mesothelioma patients.

Fas ligand (FasL), a cell surface molecule belonging to the tumor necrosis factor family, binds to its receptor Fas, thus inducing apoptosis of Fas bearing cells. In the present study we assessed the expression of Fas, activation molecule interleukin (IL)-2 receptor alpha chain (CD25) and an index of functional activity such as thymidine uptake under mitogen stimulation of tumor associated lymphomonocytes (TALM) from 7 neoplastic effusions of advanced cancer patients. The same parameters were studied in peripheral blood mononuclear cells (PBMC) of 7 patients with cancer of different sites and in 7 normal subjects. The proliferative response to phytohemagglutinin (PHA), measured as [3H]-thymidine uptake, of TALM was significantly lower than that of PBMC of cancer patients. The expression of CD25 on unstimulated fresh TALM was slightly higher than that of PBMC from normal subjects: after 24 h of PHA stimulation the CD25 was expressed both on TALM and PBMC from normal subjects. The expression of Fas was assessed on unstimulated TALM, PBMC from cancer patients and normal subjects immediately after (by 2 h, t0) the cell separation, and at different times (24 h and 48 h) thereafter, and on PHA-stimulated TALM, PBMC from cancer patients and normal subjects after 24 h and 48 h of culture (in RPMI 1640). At all times (t0, 24 h and 48 h) the Fas expression by unstimulated TALM was significantly higher than that of PBMC from normal subjects: the Fas expression by PBMC from cancer patients was roughly in the same range as PBMC from normal subjects. At 24 h the Fas expression by PHA-stimulated TALM was significantly higher than that of PBMC from normal subjects, whereas at 48 h the difference was not significant. The TALM studied by us showed to be functionally defective and expressing relatively high levels of Fas showing the characteristics to be considered as a target for FasL expressing tumor cells, which in this way may escape immune control.

Telomerase is a ribonucleoprotein that synthesizes telometric DNA on chromosome ends, and may be related to the aging and immortality of cells. Recently, a telometric repeat amplification protocol (TRAP) assay for telomerase activity, using the polymerase chain reaction, was developed. We examined the limitations of TRAP assay by applying it to a cultured colon cancer cell line (COLO320) and 58 human cytological materials from body cavity effusions, and obtained the following results; i) The limits of the TRAP assay were 20-50 cells for the COLO320 cell line; ii) One COLO320 cell per 100 normal blood white cells was detectable; iii) Seventeen of 58 samples were positive for telomerase activity in this study. The sensitivity was 69% (9/13) and the specificity was 87.5% (28/32) between cytological diagnosis and telomerase activity; iv) Among 29 malignant cases, 15 were positive for telomerase activity, while there were 11 cytologically positive cases. The positive cases detected by the combination of cytology and telomerase activity accounted for 21 of the total 29 cases (72.4%). These results suggest that the measurement of telomerase activity in body cavity effusions may be useful as an adjunctive tool for cytological and clinicopathological diagnosis and that this technique is potentially applicable to remnant cytological materials.

Distinction between benign reactive mesothelial cells and metastatic breast adenocarcinoma cells in effusions from patients with a known prior history of breast cancer is not the easiest task in diagnostic pathology. Here, we report the usefulness of testing the expression of class I HLA antigens (HLA A, B, C) in this respect. Cytospins were prepared from effusions of patients without the history of breast cancer (5 cases) and from effusions of patients with infiltrating ductal carcinoma (11 cases). Three effusions from cancerous patients were not malignant cytologically. The expression of HLA-A, B, C, HLA-DR and beta2-microglobulin as well as the macrophage antigen, CD14, was evaluated by immunocytochemistry. In 10 of 11 effusions the cytologically malignant cells expressed very weak or undetectable HLA-A,B,C as compared to the mesothelial cells and macrophages. The paucity of expression of HLA-A, B, C was detectable in those 3 cases where a definitive cytological diagnosis of malignancy could not be established. In contrast, mesothelial cells and macrophages from all samples were uniformly and strongly positive for both HLA-A, B, C and beta2-microglobulin. We conclude that the paucity of HLA-I antigens provides a marker helpful in distinguishing metastatic breast carcinoma cells from reactive mesothelial cells in effusions.

Malignant cells exhibit increased rates of glycolysis and glucose uptake, and several types of cancer have been reported to overexpress the GLUT1 glucose transporter. The diagnosis of malignancy in body cavity effusions remains a dilemma in certain cases, despite recent progress in diagnostic immunocytochemistry. We used immunostaining to detect the facilitative glucose transporter, GLUT1, in cytologic preparations of body cavity effusions and washes. With the use of standard avidin-biotin immunostaining for GLUT1, we examined cell blocks of body cavity effusions or washings from 31 carcinomas, 1 lymphoma, and 25 benign effusions or washes. GLUT1 staining occurred in the malignant cell population in 29 (93.5%) of 31 carcinomatous effusions or washes. The characteristic staining pattern consisted of dense, linear staining of the plasma membrane, with accentuation at cell-cell borders, with or without cytoplasmic staining. Erythrocytes showed positive GLUT1 membrane staining, consistent with previous reports. Of 25 benign effusions, 20 were nonstaining (excepting erythrocytes), and 5 contained rare single mesothelial cells, with equivocal to very weak membrane staining. Staining of these cells was readily distinguishable from the characteristic strong staining of malignant cells, and these cells were easily distinguished from tumor cells by their benign morphologic characteristics. At least three of these latter five specimens were from patients with cirrhosis. In all of the other cases, mesothelial cells, histiocytes, and other inflammatory cells did not stain. These findings suggest that GLUT1 immunostaining could be useful in diagnostic cytopathology. The findings also suggest that enhanced glycolysis, which requires increased glucose transport, might be a survival adaptation for tumor cells in effusions, a significant number of which are hypoxic.

Malignant mesothelioma is an aggressive and rare tumor of the mesothelium which arises in serosal cavities and is strongly related to asbestos exposure. The incidence of this tumor is still increasing because of the widespread use of asbestos over the past years and the long latency of this malignancy. The paucity of well-characterized in vitro human models and the consequent shortage of experimental pharmacological studies on mesothelioma reduce the success of its clinical management. It is well known that established human cell lines represent a rapid and advantageous system for in vitro studies of several diseases, such as mesothelioma. Thus, the aim of our study was to establish and characterize a panel of selected human malignant mesothelioma cell lines in order to highlight the biology of this tumor and to test the effectiveness of new antiproliferative compounds. During the last year, we collected 10 pleural effusion samples from patients with diagnosed and pharmacologically untreated mesothelioma. Among these, we were able to isolate three continuously growing cell lines, identified as IST-Mes1, IST-Mes2 and IST-Mes3. Another previously established malignant mesothelioma cell line (MPP89) has also been included in this study. The cells in culture appeared morphologically heterogeneous: three of them (IST-Mes1, IST-Mes2, and MPP89) were spindle-shaped, and upon reaching confluence, they assumed the characteristic cobblestone-like pattern, whereas IST-Mes3 showed mixed sizes and shapes. Cell growth studies revealed that all cell lines reach exponential growth phase within 4-7 days after plating with a doubling time ranging from 37-87 hours. Finally, insulin-like growth factor-I did not stimulate cellular proliferation of both the IST-Mes1 and IST-Mes2 cell lines.