The value of calretinin and cytokeratin 56 as markers for mesothelioma in cell block preparations of serous effusions

Integrated Bioinformatics and Machine Learning Analysis Identify ACADL as a Potent Biomarker of Reactive Mesothelial Cells

Mesothelial cells with reactive hyperplasia are difficult to distinguish from malignant mesothelioma cells based on cell morphology. This study aimed to identify and validate potential biomarkers that distinguish mesothelial cells from mesothelioma cells through machine learning combined with immunohistochemistry. It integrated the gene expression matrix from three Gene Expression Omnibus data sets (GSE2549, GSE12345, and GSE51024) to analyze the differently expressed genes between normal and mesothelioma tissues. Then, three machine learning algorithms, least absolute shrinkage and selection operator, support vector machine recursive feature elimination, and random forest were used to screen and obtain four shared candidate markers, including ACADL, EMP2, GPD1L, and HMMR. The receiver operating characteristic curve analysis showed that the area under the curve for distinguishing normal mesothelial cells from mesothelioma was 0.976, 0.943, 0.962, and 0.956, respectively. The expression and diagnostic performance of these candidate genes were validated in two additional independent data sets (GSE42977 and GSE112154), indicating that the performances of ACADL, GPD1L, and HMMR were consistent between the training and validation data sets. Finally, the optimal candidate marker ACADL was verified by immunohistochemistry assay. Acyl-CoA dehydrogenase long chain (ACADL) was stained strongly in mesothelial cells, especially for reactive hyperplasic mesothelial cells, but was negative in malignant mesothelioma cells. Therefore, ACADL has the potential to be used as a specific marker of reactive hyperplasic mesothelial cells in the differential diagnosis of mesothelioma.

Case report: Abdominal mesothelioma in Atelerix albiventris

Hedgehogs, as exotic species, are more susceptible to various neoplastic conditions affecting diverse bodily systems, particularly the tegumentary, hemolymphatic, and digestive systems. Among these conditions, epithelial tumors are the most prevalent, followed by round cell tumors and mesenchymal tumors. A striking characteristic is the malignant nature of over 8% of these tumors, leading to a generally unfavorable prognosis. This study aims to present a unique case involving a 2.5 year-old male African pygmy hedgehog in Concepción, Biobío District, Chile, diagnosed with a mesenchymal neoplasia originating from mesothelial cells. The hedgehog presented to the veterinary clinic with acute abdominal pain, prompting ultrasound imaging, and comprehensive cytological, histopathological, and immunohistochemical analyses. During abdominal ultrasound, a mass was observed, and its cytological examination revealed the presence of malignant cells. The histopathological examination unveiled a diffuse mesothelial cell tissue interwoven with abundant fibrous tissue and small cysts containing serous fluid, all enveloped by flattened or cuboidal cells of mesothelial origin. Immunohistochemistry further confirmed the diagnosis, demonstrating positive immunostaining for calretinin and mesothelin markers, corroborating the diagnosis of fibrous malignant peritoneal mesothelioma. This case highlights the complexity of neoplastic conditions in hedgehogs and emphasizes the importance of multimodal diagnostic approaches for accurate identification and understanding of these rare diseases.

Chemosensitivity of three patient-derived primary cultures of canine pericardial mesothelioma by single-agent and combination treatment

Introduction

Canine mesothelioma is a rare malignant tumor that mostly affects body cavities, such as the pericardial and pleural cavities. Chemotherapy plays a crucial role in the treatment of canine mesotheliomas. We aimed to compare the antitumor effects of single-agent and combination chemotherapeutic agents on patient-derived primary cultures of canine pericardial mesothelioma established in this study. We planned to generate xenograft models for future studies.

Material and methods

Effusion samples were collected from three dogs with histologically diagnosed pericardial mesothelioma and used for primary culture. Cultured cells were characterized by immunostaining for pan-cytokeratin AE1/AE3, vimentin, Wilms' tumor suppressor gene 1 (WT1), and cytokeratin 5 (CK5). To assess the tumorigenic properties of cells in the effusion and generate a xenograft model, the cell suspension was injected into a severe combined immunodeficient (SCID) mouse either subcutaneously (SC) or intraperitoneally (IP). Lastly, chemosensitivity of established primary cultures against four drugs, doxorubicin, vinorelbine, carboplatin, and gemcitabine, by single-agent treatment as well as combination treatment of carboplatin at a fixed concentration, either 10 or 100 μM, and gemcitabine at different concentrations ranging from 0-1000 μM was assessed by cell viability assay.

Results

Primary cultures were successfully generated and characterized by dual positivity for AE1/AE3 and vimentin and positive staining for WT-1 and CK5, confirming the mesothelial origin of the cells. In the xenograft models, SC mouse developed a subcutaneous mass, whereas IP mouse developed multiple intraperitoneal nodules. The masses were histopathologically consistent with mesotheliomas. The chemosensitivity assay revealed that carboplatin had the highest anti-tumor effects among the four tested single-agent treatments. Furthermore, carboplatin at 100 μM combined with gemcitabine at clinically relevant doses demonstrated the augmented anti-tumor effects compared to single-agent treatment.

Discussion and conclusion

Primary cultures and xenograft models generated in this study could be useful tools for in vitro and in vivo studies of canine mesothelioma. Carboplatin is a highly effective chemotherapeutic agent against canine mesothelioma when used as a sole agent and in combination with gemcitabine.

Cytomorphology and immunocytochemical features of ovarian granulosa cell tumors in ascites or peritoneal washings: A retrospective review

AIM

To summarize the cytomorphology and immunocytochemistry features of OGCT in ascites or peritoneal washings.

METHODS

All cases of histology sections, cytology smears, cell block slides and immunohistochemical staining were reviewed. A panel of immunohistochemistry antibodies consisting of Inhibin, Calretinin, BerEP4 and MC was performed for diagnosis and differential diagnosis.

RESULTS

Seven positive cases (21.2%) in ascites and peritoneal washings were identified in 33 patients with OGCT, which is higher than early studies with positive rate of 7.4%. Clinicopathologic features including tumor size and the incidence of endometrial atypical hyperplasia or carcinoma (EAH/EC) displayed no statistical difference between groups with positive and negative cytology. Immunocytochemical results usually showed typical staining pattern with α-inhibin, calretinin positive and BerEP4, MC negative. Features of granulosa cells, including nuclear hyperplasia and overlapping, can be observed in all seven positive cases. Nuclear grooves or small conspicuous nucleoli were occasionally observed in the smear. However, features of cell clusters mimicking Call-Exner bodies, cytoplasmic vacuoles or single cell necrosis were not found on smear. Call-Exner bodies and mitosis can only be found on cell blocks. All cases of follow-up information were available and three cases displayed progression and there was a statistical difference between groups with positive and negative cytology.

CONCLUSION

OGCT with positive cytology in ascites and peritoneal washings tend to have a larger tumor size and higher rates of disease progression. A panel of complementary biomarkers can greatly increase the detection rate and help in differential diagnosis in ascites or peritoneal washings of OGCT.

A Case Report of Pericardial Effusion with False-Positive Mesothelioma and Adenocarcinoma Markers as the Initial Presentation of Systemic Lupus Erythematous

Pericardial effusion or the accumulation of fluid in the pericardial sac, can result from infectious, malignant, or autoimmune processes such as systemic lupus erythematous (SLE). However, pericardial effusion is infrequently the first presentation of SLE. Here, we describe the case of a 54-year-old African American woman who presented with hypertensive emergency and was found to have pericardial effusion on echocardiogram. Her hypertensive symptoms resolved with medical management and a work up were positive for serum markers of SLE and mesothelioma cell markers (calretinin, CK 5/6) and adenocarcinoma marker MOC31 in the pericardial fluid. Her effusion ultimately improved on high-dose steroid therapy and has not recurred in one year. Given normal pleura and pericardium on computed tomography (CT) imaging and long-term clinical improvement in SLE therapy, we hypothesize that she had false-positive mesothelioma markers in the setting of SLE.

Is cell block technique useful to predict histological type in patients with ovarian mass and/or body cavity fluids?

The cell block (CB) technique is a generalized method utilized for the diagnostic evaluation of body cavity fluids. Ascites cytology is one of the most important diagnostic processes for epithelial ovarian cancer. However, in clinical practice, the usefulness of the CB method to diagnose this tumor remains unelucidated. Between 2008 and 2017, 15 peritoneal or pleural fluid samples obtained from patients with ovarian or peritoneal carcinoma or other gastrointestinal malignancies were preoperatively subjected to a diagnostic evaluation to predict the histological type and original organ. The CBs were made from 10% formalin neutral buffer solution fixed sediments of fluid samples after cytological smears were made by conventional method. Four-μm thickness sections were prepared from the cell blocks and stained with immunohistochemical method, using 16 kinds of antibodies and hematoxylin eosin staining method. The cellularity, architectural patterns, and morphological details were also studied. The median (range) age of patients was 73 (35-87) years. The clinical features were identified as follows: pleural effusion in 4, ovarian mass in 7, peritoneal dissemination in 12, para-aortic nodal swelling in one, and liver tumor in one (some overlapping). Five patients had a history of prior malignancy. Finally, we could accurately diagnose the histological type in 9 patients based on subsequent biopsy, surgery, and autopsy. In all 9 women, the clinical diagnosis, CB diagnosis and final pathological diagnosis were consistent. The CB technique may be a helpful modality for evaluating fluid cytology to obtain a final histopathologic diagnosis.

The significance of detecting glucose transporter 1 and calretinin in serous effusions to differentiate between carcinoma cells and reactive mesothelial cells

BACKGROUND

The cytologic evaluation of serous effusions to distinguish malignant cells from reactive mesothelial cells (RMCs)was an enormous challenge. The purpose of this study was to investigate the diagnostic value of glucose transporter 1 (GLUT1) and calretinin (CR) in serous effusions of patients with malignant and in order to significantly ameliorate the diagnostic accuracy.

METHODS

The expressions of GLUT1 and CR were measured by streptavidin-peroxidase (S-P) immunocytochemical technique in serous effusions of 183 patients with malignant and in 95 patients with benign diseases.

RESULTS

The positive ratio of GLUT1 was 91.8% (168/183) in serous effusions from patients with malignant and 5.3% (5/95) in benign diseases, they had a significant difference (P < .01). CR was expressed 89.5% (85/95) in benign diseases and 6.6% (12/183) in malignant, it also showed an important difference (P < 0.01). The combination of GLUT1 + CR revealed the best efficiency: the sensitivity and specificity were 100% and 98.9%, respectively.

CONCLUSION

Immunocytochemical staining for GLUT1 and CR may be used as a complementary tool for the detection of malignant effusions and help to make a distinction between cancer cells and RMCs. The combination of GLUT1 and CR with immunocytochemistry stained can be achieved a higher diagnostic performance.

Immunochemistry in the work-up of mesothelioma and its differential diagnosis and mimickers

The differential diagnosis in cellular effusions with cytological atypia often includes malignant mesothelioma (MM), reactive mesothelial proliferation, and malignancies of metastatic origin, particularly carcinomas. The International Reporting System for Serous Fluid recently established guidelines for reporting MM. In conjunction with the cytomorphologic evaluation, the role of immunochemistry (IC) was emphasized as a very useful tool in the workup of serous fluids, especially with the availability of novel markers. Utilizing a panel of markers, IC allows the characterization of the cells, whether mesothelial or not, and when mesothelial origin is established, IC can frequently assist in delineating its benign or malignant nature. IC can also confirm metastatic disease, allowing the identification of the primary origin in most cases. This review summarizes the current status of IC and its role in the diagnosis of MM and its differential diagnosis in serous fluids.

Expression of Calretinin, Marker of Mesothelial Differentiation, in Pancreatic Ductal Adenocarcinoma: A Potential Diagnostic Pitfall

OBJECTIVE

Pancreatic ductal adenocarcinoma is one of the most common causes of "peritoneal carcinomatosis" and has an insidious growth pattern. Thus, it falls into the differential diagnosis of other peritoneal malignancies including malignant mesothelioma. Recently, we have encountered an undifferentiated pancreatic carcinoma presenting with peritoneal disease and exhibiting immunoreactivity to calretinin, mimicking mesothelioma. In this study, we explored the incidence of calretinin expression in pancreatic ductal adenocarcinoma.

MATERIALS AND METHODS

Calretinin immunohistochemical staining was performed on the tissue microarrays (TMAs), which were created using three 0.6 mm diameter punches per tumor (n=113). Distribution and intensity of expression were evaluated.

RESULTS

The TMAs contained 86 well/moderately differentiated and 27 poorly differentiated/undifferentiated carcinomas. Calretinin was positive in nine tumors (8%); six with diffuse and strong staining, three with focal and/or weak staining. The incidence of calretinin expression was 15% in poorly differentiated/undifferentiated carcinomas (vs. 6% in well/moderately differentiated carcinomas, p=0.03).

CONCLUSIONS

Pancreatic ductal adenocarcinomas, especially when poorly differentiated/undifferentiated, may be diffusely and strongly positive for calretinin creating a potential diagnostic challenge with malignant mesothelioma. Therefore, caution should be exercised when using this marker to explore a diagnosis of malignant mesothelioma. Tumors expressing calretinin without other mesothelial markers should prompt a careful evaluation of the morphologic and immunohistochemical features to exclude other malignancies. If the diagnosis of pancreatic ductal adenocarcinoma is considered, ductal differentiation can be demonstrated by using additional immunohistochemical markers such as mucin-related glycoproteins (MUC1, MUC5AC) and/or oncoproteins (CEA, B72.3, CA125).

Update on diagnosis and management of neoplastic pericardial disease

INTRODUCTION

Pericardial neoplasms are uncommon, mostly due to secondary involvement of the pericardium by extracardiac tumors. Clinical presentation is nonspecific, frequently leading to a delayed diagnosis. Moreover, both benign and malignant pericardial tumors may be associated with myocardial infiltration and mechanical compression of cardiac chambers, possibly precipitating clinical conditions. Pericardial tumors are indeed a diagnostic and therapeutic clinical challenge.

AREAS COVERED

This review aims to provide an overview of the main clinical characteristics of pericardial tumors, along with their management in clinical practice.

EXPERT COMMENTARY

Multimodality imaging (echocardiography, chest X-ray, CT, CMR, and PET) enable full characterization of pericardial neoplasms. An individualized strategy should be developed by a multidisciplinary team including cardiologists, oncologists, radiologists, and cardiac surgeons.

Mesothelioma Cells Depend on the Antiapoptotic Protein Bcl-xL for Survival and Are Sensitized to Ionizing Radiation by BH3-Mimetics

PURPOSE

The incidence of mesothelioma continues to rise and prognosis remains dismal owing to resistance to conventional therapies and few novel treatment options. Failure to activate apoptotic cell death is a resistance mechanism that may be overcome by inhibition of antiapoptotic Bcl-2 proteins using BH3-mimetic drugs. We investigated the role of antiapoptotic proteins in the radioresistance of mesothelioma, identifying clinically relevant targets for radiosensitization and evaluating the activity of BH3-mimetics alone and in combination with radiation therapy in preclinical models.

METHODS, MATERIALS AND RESULTS

Mesothelioma cell lines 211H, H2052, and H226 exposed to BH3-mimetics demonstrated Bcl-xL dependence that correlated with protein expression and was confirmed by genetic knockdown. The Bcl-xL inhibitor A1331852 exhibited cytotoxic (EC50, 0.13-1.42 μmol/L) and radiosensitizing activities (sensitizer enhancement ratios, 1.3-1.8). Cytotoxicity was associated with induction of mitochondrial outer membrane permeabilization and caspase-3/7 activation. Efficacy was maintained in a 3-dimensional model in which combination therapy completely eradicated mesothelioma spheroids. Clinical applicability was confirmed by immunohistochemical analysis of Bcl-2 proteins in patient samples and radiosensitizing activity of A1331852 in primary patient-derived mesothelioma cells.

CONCLUSIONS

Mesothelioma cells exhibit addiction to the antiapoptotic protein Bcl-xL, and their intrinsic radioresistance can be overcome by small molecule inhibition of this novel therapeutic target.

Useful Application of Immunostaining to Malignant Pleural Effusion among Lao People in Vientiane Capital, Lao PDR

Background: Pathology and laboratory medicine (PALM) services are limited in low-resource countries, such as Lao PDR. Patients with malignant pleural effusion (MPE) are not properly diagnosed and treated in these situations. The purpose of this study is to confirm the usefulness of immunocytochemistry in MPE to identify the histological type and probable primary site of cancer of MPE and to discuss its usefulness in low-resource countries, such as Laos. Methods: We retrospectively reviewed glass slides of pleural effusion sent to the Department of Pathology at the University of Health Sciences from the central hospitals for cytological screening from January 2012 to December 2016. The cytological review, cell transfer and immunocytochemical staining were performed at Tokyo Medical and Dental University. Among 81 cases of MPE from Laos, 66 cases of malignant tumors that contained enough tumor cells were included in this study, and the slides were screened with 14 primary antibodies to classify the histological type and identify the probable primary site of carcinoma. Results: Among the 66 cases, 34 cases (52%) were of female patients, and 32 cases (48%) were of male patients. The patients’ ages ranged from 28 to 88 years with an average of 58 years. The immunocytochemical study identified 32 cases (49%) of primary lung adenocarcinoma, two cases (3%) of malignant mesothelioma, one case (1.5%) of breast/gynecological carcinoma, one case (1.5%) of T cell lymphoma, and one case (1.5%) of B cell lymphoma. Twenty-nine cases (43.5%) were classified as carcinoma not otherwise specified. Pulmonary small cell carcinoma/squamous cell carcinoma and metastatic colon, prostate, and liver carcinoma were not identified among the cases. Conclusions: Immunocytochemistry is a useful ancillary method in MPE diagnostics. This method could be applied in the pathological laboratories in low- or middle-resource countries, such as Laos.

Cytological Smear and Cell Block Versus Tissue Biopsies in the Diagnosis of Malignant Tumours in Non-Gynaecologic Specimens

Background

Cytological smear and cell block (CB) are routinely used to diagnose non-gynaecologic specimens. However, there is scanty information in the literature to compare cytological smear and CB with the corresponding tissue biopsies. This study is aimed at evaluating the accuracy of cytological smear and CB in the diagnosis of malignant tumours in non-gynaecologic specimens.

Materials and Methods

A total of 70 malignant cases were subjected to cytological smear and CB. Corresponding histopathology was also included. The most frequent immunomarkers found between CB and tissue biopsies were also correlated. Accuracy, sensitivity, specificity, positive predictive value, negative predictive value, false positive and false negative values were analyzed for each method.

Results

The accuracy, sensitivity and positive predictive value for cytological smear were 92.8%, 100.0% and 92.9%, whereas for CB were 91.4%, 98.4% and 92.7%, respectively. In CB method, the accuracy, sensitivity and positive predictive value for CK7 were 88.9%, 91.7% and 95.6%, whereas for CK5/6 were 75%, 100% and 57.1%, respectively.

Conclusion

Cytological smear and CB are very sensitive and accurate in the detection of malignant tumours in nongynaecologic specimens. Additional corresponding tissue biopsies should be re-evaluated.

Overexpressed genes in malignant pleural mesothelioma: implications in clinical management

Malignant pleural mesothelioma (MPM) is a very aggressive cancer poorly responsive to current therapies. MPM patients have a very poor prognosis with a median survival of less than one year from the onset of symptoms. The biomarkers proposed so far do not lead to a sufficiently early diagnosis for a radical treatment of the disease. Thus, the finding of novel diagnostic and prognostic biomarkers and therapeutic targets is needed. Gene overexpression has been frequently associated with a malignant phenotype in several cancer types; therefore the identification of overexpressed genes may lead to the detection of novel prognostic or diagnostic marker and to the development of novel therapeutic approaches, based on their inhibition. In the last years, several overexpressed genes have been identified in MPM through gene expression profiling techniques: among them it has been found a group of 51 genes that resulted overexpressed in more than one independent study, revealing their consistency among studies. This article reviews the clinical implications of confirmed overexpressed genes in MPM described so far in literature.

Improving the cytological diagnosis of high-grade serous carcinoma in ascites with a panel of complementary biomarkers in cell blocks

INTRODUCTION

Precise cytological diagnosis of pelvic high-grade serous carcinoma (HGSC) in ascites is important for tumour staging, therapeutic decision-making and prognostic evaluation. However, it can often be difficult to distinguish metastatic HGSC cells from reactive mesothelial cells based on morphology alone. Immunocytochemical analysis of ascites cell blocks has been used to obtain accurate diagnosis and provide a reliable basis for treatment decisions in the clinic. This study was performed to determine whether a panel of antibodies is necessary to achieve high specificity and sensitivity for the identification of HGSC cells.

METHODS

Ascites samples from 70 cases (70/253, 27.7%) of histologically confirmed HGSC were postoperatively collected from 2012 to 2015 and were immunocytochemically analysed.

RESULTS

The sensitivity and specificity of Ber-EP4 (a marker of HGSC) for detecting HGSC was 85.7% and 82.1%, respectively, whereas the sensitivity and specificity of HBME-1 for identifying mesothelial cells was 100% and 68.3%, respectively. To improve the rate of detection further of HGSC, 29 cases of ascites were also stained for E-cadherin (a marker of HGSC) and calretinin (a marker of mesothelial cells). The combination of Ber-EP4 and E-cadherin as markers of adenocarcinoma cells increased the sensitivity and specificity for HGSC detection to 100% and 88.9%, respectively. Meanwhile, the sensitivity and specificity for mesothelial cell identification increased to 100% and 90%, respectively, when HBME-1 and calretinin were combined.

CONCLUSION

This panel of complementary biomarkers is valuable and ideal for the differential diagnosis of HGSC based on ascites cytology.

Chronic mesothelial reaction and toxicity of potassium octatitanate fibers in the pleural cavity in mice and F344 rats

Fiber‐shaped particles of potassium octatitanate (tradename TISMO; chemical formula K₂O·6TiO₂), which are morphologically similar to asbestos particles, were shown to induce severe proliferative reactions in the pleural mesothelium in a previous experiment carried out over 21 weeks. The present study aims to determine whether these fibers induce malignant mesotheliomas in rodents, and to examine chronic toxicity induced. Additionally, we investigated the specific differences observable between the biological responses to the direct infusion of the fibers alone into the pleural cavity and those induced by the co‐administration of the fibers with a known carcinogen. To detect the induction of malignant pleural mesotheliomas, two experiments were undertaken. In Experiment 1, four strains of mice, A/J, C3H, ICR, and C57BL, were examined for 52 weeks after experimental treatment with TISMO. In Experiment 2, the F344 rats were treated with TISMO alone, the lung carcinogen N‐bis (2‐hydroxypropyl) nitrosamine (DHPN) alone, both TISMO and DHPN, or left untreated and were then examined for 52 weeks. In this experiment, malignant lesion induction was expected in the co‐administration group. TISMO fibers were observed in the alveoli, indicating penetration through the visceral pleura in mice and rats. The histopathological detection of TISMO fibers in the liver and kidneys of mice and rats indicated migration of the fibers out of the pleural cavity. Atypical mesothelial cells with severe pleural proliferation were observed, but malignant mesotheliomas were not detected. Among the rats, there were no observed malignant alterations in the mesothelium induced by DHPN–TISMO co‐administration.

2015 update on the diagnosis and management of neoplastic pericardial disease

The best approach in diagnosis and treatment of neoplastic pericardial disease has not been defined yet. The authors report the most recent literature about the new diagnostic techniques that are useful to improve the diagnosis. The literature about the therapeutic options is critically reviewed, in order to give suggestions of use to the clinical practice. Pericardial effusion may require urgent drainage; the solid component, however, becomes predominant in some cases. Neoplastic pericardial disease should be assessed following oncologic criteria evaluation of the neoplastic burden; outcome classified as complete or partial response, stable or progressive disease and - in cases with progression - event-free survival. Systemic chemotherapy may be effective in lymphomas and possibly in breast carcinomas. Intrapericardial chemotherapy with systemic chemotherapy is the treatment of choice in lung cancer. Pericardial window with systemic chemotherapy is also effective in preventing the accumulation of large amount of fluid.

Long-Term Chronic Toxicity and Mesothelial Cell Reactions Induced by Potassium Octatitanate Fibers (TISMO) in the Left Thoracic Cavity in A/J Female Mice

The present study was conducted to examine the chronic effects of potassium octatitanate fibers (trade name TISMO; chemical formula K2O·6TiO2) on the mouse lung and thoracic cavity. This method of infusion was employed to examine the direct effects of the fibers to the pleura. In the present study, 52- and 65-week experiments were employed to examine the long-term chronic effects after infusion of fiber-shaped TISMO into the thoracic cavities of A/J mice. Following this infusion, TISMO fibers were observed in the alveoli, indicating penetration through the visceral pleura. The additional histopathological detection of TISMO fibers in the liver, spleen, kidneys, ovary, heart, bone marrow, and brain of TISMO-infused mice indicated migration of the fibers out from the thoracic cavity. Atypical mesothelial cells with severe pleural proliferation were observed, but malignant mesotheliomas were not detected. This study demonstrated that intrathoracic infusion of TISMO fiber did not cause malignant mesothelioma but did cause severe chronic inflammation and proliferation of pleural mesothelial cells.

Retrospective analysis of unknown primary cancers with malignant pleural effusion at initial diagnosis

Background

Malignant pleural effusion (MPE) can occur during the progression of various cancers. However, factors, such as the incidence of MPE associated with different types of cancers and its potential for diagnosing previously undetected cancers, are unknown. Moreover, MPE may accompany potentially curable cancers or those with a favorable survival prognosis with adequate treatment. The present study determined the types of cancers accompanied by MPE at initial diagnosis and investigated appropriate related methods for diagnosing previously unknown cancers.

Methods

We retrospectively reviewed the medical records of 35 patients with MPE at initial cancer diagnosis between 2004 and 2012. We evaluated the patient characteristics, final diagnosis, and diagnostic processes.

Results

Of the 35 patients, 10 had lung cancer, seven ovarian or peritoneal cancer, four malignant pleural mesothelioma, one breast cancer, one lymphoma, one pancreatic cancer, and 11 had cancers of unknown origin. Diagnoses of the primary lesions were confirmed using the MPE cellblock method for seven of 11 patients (63.6%), by excisional biopsy or aspiration from other sites in four of nine patients, by exploratory laparotomy in two of three patients, and by peritoneal washing cytology in five patients.

Conclusion

Lung cancer and cancer of unknown origin are major causes of MPE at initial presentation. However, these groups also contain cancers that are curable and those with good long‐term prognosis. The MPE cellblock method represents an accurate method for identifying cancer origin.

Diagnostic accuracy of calretinin for malignant mesothelioma in serous effusions: a meta-analysis

Numerous studies have investigated the utility of calretinin in differentiating malignant mesothelioma (MM) from metastatic carcinoma (MC) in serous effusions. However, the results remain controversial. The aim of this study is to determine the overall accuracy of calretinin in serous effusions for MM through a meta-analysis of published studies. Publications addressing the accuracy of calretinin in the diagnosis of MM were selected from the Medline (Ovid), PubMed, the Cochrane Library Database and the Web of Science. Data from selected studies were pooled to yield summary sensitivity, specificity, positive and negative likelihood ratio (LR), diagnostic odds ratio (DOR), and receiver operating characteristic (SROC) curve. Statistical analysis was performed by Meta-Disc 1.4 and STATA 12.0 softwares. 18 studies met the inclusion criteria and the summary estimating for calretinin in the diagnosis of MM were: sensitivity 0.91 (95%CI: 0.87–0.94), specificity 0.96 (95%CI: 0.95–0.96), positive likelihood ratio (PLR) 14.42 (95%CI: 7.92–26.26), negative likelihood ratio (NLR) 0.1 (95%CI: 0.05–0.2) and diagnostic odds ratio 163.03 (95%CI: 54.62–486.63). The SROC curve indicated that the maximum joint sensitivity and specificity (Q-value) was 0.92; the area under the curve was 0.97. Our findings suggest that calretinin may be a useful diagnostic tool for confirming MM in serous effusions.

Claudin-4 immunohistochemistry is highly effective in distinguishing adenocarcinoma from malignant mesothelioma in effusion cytology

BACKGROUND

Adenocarcinoma can be challenging to distinguish from malignant mesothelioma in effusions, and this distinction often requires ancillary studies and clinical correlation. Immunohistochemistry for claudin-4, a tight-junction-associated protein, has recently been shown to distinguish adenocarcinoma from malignant mesothelioma, mostly in surgical specimens. Our aim was to validate and assess the immunoreactivity profile of claudin-4 in a large series of malignant effusions.

METHODS

We evaluated 159 malignant effusions (84 adenocarcinomas and 75 malignant mesotheliomas). Claudin-4 immunohistochemistry was performed on cell-block paraffin sections and scored for staining intensity, staining pattern (cytoplasmic versus membranous), and percentage of positive tumor cells. Appropriate positive and negative controls were used throughout.

RESULTS

All cases of mesothelioma were negative for claudin-4 (0 of 64). Eighty-three of 84 cases of adenocarcinoma were positive (99%); 1 case of serous carcinoma was negative. Most adenocarcinomas showed strong and diffuse membranous staining (71 of 84; 84%); 12 cases (14%) showed membranous staining of moderate intensity. The overall sensitivity for adenocarcinoma was 99% (83 of 84).

CONCLUSIONS

Claudin-4 immunohistochemistry effectively distinguishes adenocarcinoma from malignant mesothelioma with high sensitivity and specificity in the evaluation of malignant effusions.

Strain differences in pleural mesothelial cell reactions induced by potassium octatitanate fibers (TISMO) infused directly into the thoracic cavity

Although we have previously reported that the fiber-shaped TISMO, morphologically similar to asbestos, can induce a severe mesothelial reaction in A/J mice, it is important to clarify any strain differences. In the present study, female A/J, C3H/HeN, ICR and C57BL/6 mice were therefore employed as test strains. At the beginning of the experiment, all mice underwent a left thoracotomy and direct administration of 3mg of TISMO particles suspended in 0.2 ml saline into the left thorax. The experiment was terminated after 21 weeks and all groups were sacrificed and the mesothelium and main organs were examined histopathologically. To contribute to mechanistic analysis, iron staining with Berlin blue and Turnbull's blue, and immunostaining for calretinin were also performed. The present experiment demonstrated only minor strain differences in the degree of pleural reaction to TISMO. However, there was clear variation in the iron and lymphocyte accumulation in the pleura and in the liver. This difference in response to TISMO fibers in vivo is important information when considering the development of mesothelioma as an animal model and the extrapolation to human risk from such animal studies.

Adenocarcinoma cells in effusion cytology as a diagnostic pitfall with potential impact on clinical management: a case report with brief review of immunomarkers

Distinguishing metastatic carcinoma cells from reactive mesothelial cells in effusion samples is often challenging based on morphology alone. Metastatic carcinoma cells in fluid samples may mimic reactive mesothelial cells due to overlapping cytological features. We report a case of a pleural effusion in a 51-year-old female patient with a medical history significant for bilateral ovarian tumors and peritoneal implants diagnosed as serous tumor of borderline malignant potential. The effusion was composed almost entirely of adenocarcinoma cells that morphologically mimicked reactive mesothelial cells. The diagnosis of metastatic adenocarcinoma was made after a wide immunostaining panel of antibodies. Recognizing metastatic adenocarcinoma cells in effusion samples can be challenging and an accurate diagnosis may have significant impact on clinical management as demonstrated by this case.

Advances in the diagnosis of pleural disease in lung cancer

Pleural disease in lung cancer can be benign or malignant with the latter carrying a grave prognosis. In this review, we describe and discuss the advances in pleural imaging, procedures, and biomarkers for the diagnosis of pleural diseases in lung cancer. Ultrasound and computed tomography are increasingly applied in the planning of pleural procedures to enhance diagnostic accuracy and safety whilst pleuroscopy gives excellent yield in excess of 93% in the evaluation of cytology negative pleural effusions. Invasion beyond the elastic layer of the visceral pleura upstages lung cancer, and may indicate a need for adjuvant chemotherapy. Biomarkers isolated from pleural fluid or tissue may aid in diagnosis and guide treatment in the future. Magnetic resonance imaging, positron emission tomography, narrow band imaging of the pleura and autofluorescence thoracoscopy are technologies that require further evaluation to better define their respective roles in the diagnostic algorithms of pleural diseases in lung cancer.

Neoplastic pericardial disease: Old and current strategies for diagnosis and management

The prevalence of neoplastic pericardial diseases has changed over time and varies according to diagnostic methods. The diagnostic factor is usually the detection of neoplastic cells within the pericardial fluid or in specimens of pericardium, but the diagnosis may be difficult. Accurate sampling and cytopreparatory techniques, together with ancillary studies, including immunohistochemical tests and neoplastic marker dosage, are essential to obtain a reliable diagnosis. The goals of treatment may be simply to relieve symptoms (cardiac tamponade or dyspnea), to prevent recurrent effusion for a long-term symptomatic benefit, or to treat the local neoplastic disease with the aim of prolonging survival. Immediate relief of symptoms may be obtained with percutaneous drainage or with a surgical approach. For long term prevention of recurrences, various approaches have been proposed: extended drainage, pericardial window (surgical or percutaneous balloon pericardiostomy), sclerosing local therapy, local and/or systemic chemotherapy or radiation therapy (RT) (external or with intrapericardial radionuclides). The outcomes of various therapeutic approaches vary for different tumor types. Lymphoma and leukemias can be successfully treated with systemic chemotherapy; for solid tumors, percutaneous drainage and the use of systemic and/or local sclerosing and antineoplastic therapy seems to offer the best chance of success. The use of "pure" sclerosing agents has been replaced by agents with both sclerosing and antineoplastic activity (bleomycin or thiotepa), which seems to be quite effective in breast cancer, at least when associated with systemic chemotherapy. Local chemotherapy with platinum, mitoxantrone and other agents may lead to good local control of the disease, but the addition of systemic chemotherapy is probably relevant in order to prolong survival. The surgical approach (creation of a pericardial window, even with the mini-invasive method of balloon pericardiostomy) and RT may be useful in recurring effusions or in cases that are refractory to other therapeutic approaches.

Potassium octatitanate fibers (TISMO) induce pleural mesothelial cell reactions with iron accumulation in female A/J mice

It is crucial to develop therapeutic approaches for malignant mesothelioma, as well as to obtain information involving the possible mechanism involved in the development of mesothelioma. Subsequently, thoracotomy was performed to infuse test particles directly into the thoracic cavity of A/J mice. Fiber-shaped particles of potassium octatitanate (TISMO) and granular-shaped micro- and nano-size order particles of titanium dioxide (TiO(2)) were employed (1.5 mg in 0.2 ml saline/mouse). The experiment was terminated after 21 weeks to assess responses. Only the fiber-shaped TISMO, morphologically similar to asbestos, induced a severe reaction of the pleura. A number of TISMO fibers were observed in the alveoli, indicating penetration through the pleura. Following Berlin blue staining, positive spots were observed around the TISMO fibers, indicative of iron. These positive spots corresponded with cells that immunostained positively for calretinin, a marker of mesothelial cells. Similar observations were reported for asbestos-induced mesothelioma. The present study showed that only fiber-shaped TISMO induced severe reactions of the mesothelium in the pleura, and these involved iron accumulation derived from endogenous sources. The results indicate that the risk of mesothelial cell reaction does not depend on particle size, but may depend on shape.

Cytomorphologic characteristics of fine needle core biopsy of multicystic peritoneal mesothelioma: a case report and review of the literature

Multicystic peritoneal mesothelioma (MPM) is an uncommon cystic mesothelial proliferative lesion. It occurs predominantly in women of reproductive age and most commonly arises in the pelvis. The preoperative diagnosis of MPM is difficult to establish based on clinical and radiographic findings, and has therefore traditionally been diagnosed following surgical resection. Due to differing management of MPM and its differential diagnoses including both benign and malignant lesions, it would be beneficial to diagnose MPM preoperatively. We report a case of MPM in a middle aged female that was diagnosed by fine needle core biopsy and touch preparations, allowing for appropriate clinical management. The cytomorphologic features of needle core biopsy, immunocytochemical studies and differential diagnosis are discussed. Furthermore, despite its infrequency, the current case emphasizes the importance of the inclusion of this entity in the differential diagnosis of cystic lesions of the abdomen and pelvis at the time of on-site evaluation and final diagnosis, in order to avoid misinterpretation of strips of benign mesothelial cells as inadequate for diagnosis.