Use of a panel of markers in the differential diagnosis of adenocarcinoma and reactive mesothelial cells in fluid cytology

Diagnostic Utility of Claudin4 and Comparison with BerEp4 as a Marker for Metastatic Adenocarcinoma in Serous Effusions

INTRODUCTION

Fluid cytology for malignant cells is important for diagnosis and staging of malignancies. Morphological overlap between reactive mesothelial cells and adenocarcinoma poses challenges, for which many immunohistochemical markers like BerEp4 and MOC-31 have been used extensively. Claudin4 is a new marker with promising results; however, further studies are required to establish its role as a pan-carcinoma marker in serous effusions. This study aimed to determine the utility of Claudin4 in diagnosing metastatic adenocarcinoma in effusions and comparing its performance with BerEp4.

METHODS

Claudin4 immunohistochemistry (IHC) was performed on effusion cell blocks (n = 60) reported as positive or suspicious for metastatic adenocarcinoma on cytology over a 1-year period and was scored for intensity (0-3) and percentage of positive cells (0-4). The results were compared with BerEp4 IHC and correlated with follow-up. Ten benign effusions were included as negative controls.

RESULTS

Claudin4 IHC was positive in all 60 (100%) cases, irrespective of the primary site. BerEp4 IHC was positive in 58 (96.7%) fluids and negative in 2 (3.3%) cases. All 10 benign effusions were negative for Claudin4 and BerEp4. Claudin4 showed higher intensity and proportion scores as compared to BerEp4 in cases where tumor cells were predominantly singly scattered and was comparable to BerEp4 where tumor cells were arranged in groups. Sensitivity, specificity, PPV, and NPV of Claudin4 in our study was 100%. Sensitivity, specificity, PPV, and NPV of BerEP4 was 96.7%, 100%, 100%, and 83.3%, respectively.

CONCLUSION

Claudin4 IHC staining results were comparable to BerEp4, irrespective of the primary site, and it performed better in cases where tumor cells were predominantly scattered singly.

Serous fluid: Reactive conditions

This chapter highlights the steps that would help to analyze any fluid. It highlights importance of knowing gross analysis of fluid along with biochemical information. These parameters along with clinical information are very important in arriving at a differential diagnosis. Morphologic appearances in the fluid can often become challenging and occasionally reactive conditions can reveal changes that may mimic malignancies. This chapter provides not only a framework of approach to assessment of fluid cytology but also shows how to distinguish some of the challenging reactive conditions from the diagnosis of carcinoma. The chapter also utilizes two cases to demonstrate approach to reactive conditions. This review article will be incorporated finally as one of the chapters in CMAS (CytoJournal Monograph/Atlas Series) #2. It is modified slightly from the chapter by the initial authors in the first edition of Cytopathologic Diagnosis of Serous Fluids.

Serous cavity metastasis: Evaluation of unknown primary

Malignant effusions can occur in patients with neoplasia. Once a metastatic diagnosis is confirmed, the primary site of origin of malignancy needs to be ascertained. This task can be challenging without a prior history of malignancy. In some patients their effusion may be the initial presentation of an underlying malignancy. Metastases usually present with a dual population of mesothelial and malignant cells. Combining cytomorphologic examination with ancillary testing such as immunocytochemistry can help identify the origin of the foreign malignant cell population. Helpful architectural clues include a single cell pattern, solid cell ball pattern, single file arrangement, papillary formation, psammoma bodies and background mucin. Useful cellular features include the presence of signet ring cells, small cells, pleomorphic and multinucleated giant cells, squamous cells, spindle cells and pigmentation. Rarely, despite an extensive work-up the primary site of origin for a malignant effusion may remain unresolved. This review article will be incorporated finally as one of the chapters in CMAS (CytoJournal Monograph/Atlas Series) #2. It is modified slightly from the chapter by the initial authors in the first edition of Cytopathologic Diagnosis of Serous Fluids.

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.

"Single-cell pattern" of adenocarcinoma cells in effusion cytology: Morphologic challenges of lung cancer

BACKGROUND

Lung adenocarcinomas present as tight clusters and three-dimensional balls in effusion specimens. Unlike carcinomas of breast and stomach where singly lying malignant cells are seen in effusion samples, lung adenocarcinomas usually show cohesive morphology. This single-cell pattern may also be confused with reactive mesothelial cells. We studied the frequency of pulmonary adenocarcinoma with single-cell pattern cytomorphology in pleural effusion specimens.

MATERIALS AND METHODS

All cases reported as either suspicious or positive for malignancy on pleural effusion cytology (PFC) over the past 1 year were retrieved. The clinical details were obtained from requisition forms. Cases with predominant single-cell pattern, clinically suspicious of carcinoma lung were segregated. These were de-stained and immunocytochemistry (ICC) for TTF-1 was performed.

RESULTS

Of 103 cases reported as either suspicious or positive for malignancy on PFC, 29 had a predominant single-cell pattern. Of these, 13 (44.8%) were primary lung carcinoma. The rest were metastasis from ovary (5; 17.2%), breast (2; 6.9%), stomach (2; 6.9%), lymphoma (1; 3.5%), and Ewing's sarcoma (1; 3.5%). Five (17.2%) were those with unknown primary. All cases of lung carcinoma were positive for TTF-1 ICC.

CONCLUSION

Single-cell pattern of pulmonary adenocarcinoma is commoner than popularly believed. This pattern may be difficult to differentiate from carcinoma cells of other sites as well as from reactive mesothelial cells. A high degree of suspicion is therefore needed to perform relevant ICC to clinch the correct diagnosis.

Morphologic and Immunocytochemical Features of High-Grade Serous Carcinoma of Ovary in Ascitic Fluid Effusion and Fine-Needle Aspiration Cytology

OBJECTIVES

High-grade serous carcinoma (HGSC) is the most common ovarian malignancy. The role of cytopathology in obtaining tissue diagnosis before institution of neoadjuvant chemotherapy (NACT) was evaluated.

METHODS

All histopathology-proven HGSC specimens between 2015 and 2018 with prior cytopathologic diagnosis by ascitic fluid evaluation or fine-needle aspiration (FNA) of ovarian mass were reviewed with cell block immunocytochemistry for CK7, CK20, PAX8, WT1, and p53.

RESULTS

Of 288 cases of HGSC, pre-NACT cytology diagnosis was established in 32% (93/288), with specific HGSC diagnoses made on ascitic fluid in 88% (82/93) and by ovarian mass FNA in 12% (11/93). The ascitic fluid showed moderate/high cellularity with papillary clusters in 76% (71/93) cases. Cell block immunocytochemistry showed tumor cells positive for CK7, PAX8, and WT1. p53 showed mutant or null-type positivity in 65% (33/51) and 33% (17/51) of cases, respectively, with 100% concordance with subsequent histopathology specimens. Poor/intermediate response to chemotherapy was shown in 75% of cases.

CONCLUSIONS

Combined assessment of cytomorphology, cell block histomorphology, and ancillary immunohistochemical testing, including PAX8, WT1, and p53, allows for specific pre-NACT diagnoses of HGSC in ascitic fluid and ovarian FNA cytology. This practice allows for initiation of chemotherapy and diminution of disease burden prior to definitive surgical therapy.

Diagnostic Value of the EZH2 Immunomarker in Malignant Effusion Cytology

BACKGROUND

Differentiating reactive mesothelial cells from metastatic carcinoma in effusion cytology is a challenging task. The application of at least 4 monoclonal antibodies including 2 epithelial markers (Ber-EP4, MOC-31, CEA, or B72.3) and 2 mesothelial markers (calretinin, WT-1, CK5/6, or HBME-1) are often useful in this distinction; however, it is not readily available in many resource-limited developing countries. Aberrant immunoexpression of enhancer of zeste homolog 2 (EZH2), a transcriptional repressor involved in cancer progression, is observed widely in various malignancy. In this study, we evaluate the diagnostic value of EZH2 as a single reliable immunomarker for malignancy in effusion samples.

METHODS

A total of 108 pleural, peritoneal, and pericardial effusions/washings diagnosed as unequivocally reactive (n = 41) and metastatic carcinoma (n = 67) by cytomorphology over 18 months were reviewed. Among the metastatic carcinoma cases, 54 were adenocarcinoma and others were squamous cell carcinoma (n = 1), carcinosarcoma (n = 1), and carcinoma of undefined histological subtypes (n = 11). Cell block sections were immunostained by EZH2 (Cell Marque, USA). The percentages of EZH2-immunolabeled cells over the total cells of interest were calculated. Receiver operating characteristic (ROC) curve analysis was performed to determine the optimal cut-off score to define EZH2 immunopositivity.

RESULTS

A threshold of 8% EZH2-immunolabeled cells allows distinction between malignant and reactive mesothelial cells, with 95.5% sensitivity, 100% specificity, 100% positive predictive value, and 93.2% negative predictive value (p < 0.0001). The area under the curve was 0.988.

CONCLUSION

EZH2 is a promising diagnostic biomarker for malignancy in effusion cytology which is inexpensive yet trustworthy and could potentially be used routinely in countries under considerable economic constraints.

Use of Panel of Markers in Serous Effusion to Distinguish Reactive Mesothelial Cells from Adenocarcinoma

Introduction:

Although cytological examination helps in diagnosis of malignancy in serous effusion, at times it is difficult to differentiate atypical reactive mesothelial cells from adenocarcinoma (AC) cells. To resolve this problem, various ancillary methods have been used. Immunocytochemistry (ICC) is one such commonly used technique in which various panel of antibodies has been tried. Unfortunately, so far no unique marker is available to solve this issue. Hence, the present study evaluates the efficacy of four antibody panel comprising of MOC-31, epithelial membrane antigen (EMA), calretinin (CAL), and mesothelin (MES) to solve this problem.

Materials and Methods:

Forty-two cases suspected of malignant effusion in pleural/peritoneal fluid and 42 cases of reactive effusion were included. Cytospin smears were prepared and stained with Giemsa stain for cytomorphological diagnosis. Cytospin smears and cell blocks were made forICC. ICC for MOC-31, EMA, CAL, and MES was performed.

Results:

Among the suspected malignant effusion cases, 30 cases were AC and 12 cases were suspicious for malignancy by cytomorphology. MOC31 demonstrated 100% sensitivity (Sn) and 95.24% specificity (Sp), and EMA had 88.1% Sn and 92.86% Sp for AC cases. CAL demonstrated 100% and 97.62%, and MES 97.62% and 88.1% Sn and Sp in reactive mesothelial cells, respectively.

Conclusion:

In conclusion, combination of MOC-31 and CAL as a limited panel will be helpful in giving an appropriate diagnosis in difficult cases and thereby, help in patient management. In addition, ICC on cytospin smears gave results similar to cell blocks, and if standardised cytospin is simple technique to perform, unlike cell blocks.

Intratumoral Heterogeneity in Ductal Carcinoma In Situ: Chaos and Consequence

Ductal carcinoma in situ (DCIS) is a non-invasive proliferative growth in the breast that serves as a non-obligate precursor to invasive ductal carcinoma. The widespread adoption of screening mammography has led to a steep increase in the detection of DCIS, which now comprises approximately 20% of new breast cancer diagnoses in the United States. Interestingly, the intratumoral heterogeneity (ITH) that has been observed in invasive breast cancers may have been established early in tumorigenesis, given the vast and varied ITH that has been detected in DCIS. This review will discuss the intratumoral heterogeneity of DCIS, focusing on the phenotypic and genomic heterogeneity of tumor cells, as well as the compositional heterogeneity of the tumor microenvironment. In addition, we will assess the spatial heterogeneity that is now being appreciated in these lesions, and summarize new approaches to evaluate heterogeneity of tumor and stromal cells in the context of their spatial organization. Importantly, we will discuss how a growing understanding of ITH has led to a more holistic appreciation of the complex biology of DCIS, specifically its evolution and natural history. Finally, we will consider ways in which our knowledge of DCIS ITH might be translated in the future to guide clinical care for DCIS patients.

Diagnostic benefits of the combined use of liquid-based cytology, cell block, and carcinoembryonic antigen immunocytochemistry in malignant pleural effusion

Background

Malignant pleural effusion (MPE) is a common complication of cancer cell metastasis to the pleura. Discrimination between MPE and benign pleural effusion is necessary to design treatment strategies. Cytology is important for the diagnosis of MPE. Carcinoembryonic antigen (CEA) is an epithelial biomarker with a strong staining pattern in adenocarcinomas. Here, the diagnostic performances of liquid-based cytology (LBC), cell block (CB) preparation, and CEA immunostaining for the detection of malignancy in effusion cytology were compared in a large case series.

Methods

In a single institution, 1,014 cytology samples from 862 patients were retrospectively collected and reviewed between January 2013 and November 2015. Ethanol-fixed, paraffin embedded CB of pleural effusions was analyzed by CEA immunostaining. Diagnostic values were compared among LBC, CB, CEA immunostaining, and the combination of two methods.

Results

The sensitivity and specificity of the CB preparation were 94.3% and 98.7%, respectively, compared with 81.3% and 99.4% for LBC preparations, respectively. Combination of LBC and CB increased sensitivity by 98.3%. Although the accuracy of CEA staining itself was moderate (sensitivity, 89.8%), the combined use of CB and CEA tumor marker increased the detection rate of malignancy (sensitivity, 100%; specificity, 100%), compared with that of cytology (LBC or CB) alone.

Conclusions

The sensitivity and specificity for the diagnosis of MPE could be improved by integrating the CB and CEA staining into LBC in routine clinical practice to improve diagnostic accuracy.

Macrophages promote the progression of premalignant mammary lesions to invasive cancer

Breast cancer initiation, progression and metastasis rely on a complex interplay between tumor cells and their surrounding microenvironment. Infiltrating immune cells, including macrophages, promote mammary tumor progression and metastasis; however, less is known about the role of macrophages in early stage lesions. In this study, we utilized a transplantable p53-null model of early progression to characterize the immune cell components of early stage lesions. We show that macrophages are recruited to ductal hyperplasias with a high tumor-forming potential where they are differentiated and polarized toward a tumor-promoting phenotype. These macrophages are a unique subset of macrophages, characterized by pro-inflammatory, anti-inflammatory and immunosuppressive factors. Macrophage ablation studies showed that macrophages are required for both early stage progression and primary tumor formation. These studies suggest that therapeutic targeting of tumor-promoting macrophages may not only be an effective strategy to block tumor progression and metastasis, but may also have critical implications for breast cancer prevention.

PAX2 and PAX8: useful markers for metastatic effusions

OBJECTIVE

It was the aim of this study to determine the utility of PAX2 and PAX8 in cytology effusions with metastatic tumor.

STUDY DESIGN

PAX2 and PAX8 immunohistochemical staining was performed on cell blocks of 89 pleural, pericardial and peritoneal effusions with benign diagnoses (18 cases), or secondary to renal cell carcinoma (RCC; 9 cases), müllerian carcinoma (21 cases) or non-müllerian carcinoma (41 cases).

RESULTS

PAX2 stained 0% (0/18) of controls, 100% (8/8) of RCCs, 35% (7/20) of müllerian carcinomas, and 2% (1/41) of non-müllerian carcinomas. PAX8 stained 6% (1/18) of control cases, 100% (9/9) of RCC cases, 100% (20/20) of müllerian carcinomas, and 5% (2/41) of non-müllerian carcinomas. PAX2 was 35% sensitive and 95% specific for müllerian carcinoma and 100% sensitive and 95% specific for RCC. PAX8 was 100% sensitive and 95% specific for müllerian carcinoma and 100% sensitive and 95% specific for RCC.

CONCLUSIONS

PAX8 is more sensitive than PAX2 for metastatic effusions from müllerian carcinomas (100 vs. 35%), while also having a higher intensity of staining than PAX2. However, PAX2 and PAX8 are both highly sensitive and specific for RCCs. PAX2 and PAX8 are valuable diagnostic markers for metastatic müllerian carcinomas and RCCs in effusion cytology. PAX8 is superior for carcinomas of müllerian origin.

Evaluation of the sensitivity and specificity of immunohistochemical markers in the differential diagnosis of effusion cytology

OBJECTIVE

To evaluate the sensitivity and specificity of Calretinin and Carcinoembryonic antigen as immunocytochemical markers in distinguishing mesothelial cells from metastatic adenocarcinoma cells in effusion cytology.

METHODS

This study included 50 patients who presented with effusions (26 pleural and 24 peritoneal), at Al-Kadhimya Teaching Hospital who were selected according to their preliminary diagnosis from 1st December 2010 to 30th June 2011. Effusion fluids were aspirated and processed for both conventional cytological methods using Papanicolaou-stain and immunocytochemical staining with anti Calretinin and Carcinoembryonic antigen.

RESULTS

The sensitivity of cytology for detection of malignant cells was 77%, with 100% specificity and 86% accuracy. Calretinin was observed to be a specific (100%) and sensitive (90%) marker for mesothelial cells (of benign etiology). Carcinoembryonic antigen exhibited 70% sensitivity and 100% specificity for adenocarcinoma cells. When the results of both cytology and immunocytochemistry were considered in conjunction, the sensitivity for the detection of malignancy increased to 97%, with 100% specificity and 98% accuracy.

CONCLUSION

Calretinin and Carcinoembryonic antigen were found to be useful markers for differentiating reactive mesothelial cells from metastatic adenocarcinoma cells in smears prepared from body fluids. Also, the combination of both cytology and immunocytochemical studies using the two markers can greatly enhance the diagnostic accuracy, sensitivity and specificity in malignant effusions.

Diagnostic value of E-cadherin and fibronectin in differentiation between reactive mesothelial and adenocarcinoma cells in serous effusions

BACKGROUND

One of the problems in studying serous effusion cytological samples is differentiation of reactive mesothelial cells from metastatic adenocarcinoma cells.

MATERIALS AND METHODS

In this study, the immunohistochemical diagnostic value of E-cadherin and fibronectin markers for differentiation of these 2 groups of cells was studied. 50 cell block samples prepared from serous effusions were examined. Based on clinical and histological studies, 25 cases had primary carcinoma, and the other 25 were proved to be benign effusion cases. All the cases were studied for E-cadherin and fibronectin immunostaining using an envision technique. Statistical analyzes were performed employing Chi-square and exact Fisher tests, using SPSS software (version 16).

RESULTS

24 of the 25 benign cases were stained with fibronectin and 2 with E-cadherin, whereas from among the 25 metastatic cases, 2 reacted to fibronectin and 22 to E-cadherin. Considering the staining of the 2 markers under conditions that the cells were stained with fibronectin but not with E-cadherin, positive predictive value (PPV) and negative predictive value (NPV) to identify reactive mesothelial cells were 100% and 92.5% while under conditions that had not been stained with fibronectin but with E-cadherin, PPV and NPV to detect adenocarcinoma cells were 95.2% and 82.1%, respectively.

CONCLUSION

Employing this short panel can be helpful for better differentiation of adenocarcinoma and reactive mesothelial cells in serous fluids.

Immunohistochemical analysis of the ubiquitin-conjugating enzyme UbcH10 in lung cancer: a useful tool for diagnosis and therapy

The ubiquitin-conjugating enzyme (UbcH10) plays important roles in the regulation of cell cycle progression. Recently, UbcH10 expression has been demonstrated in several human and experimental tumors, and proteasome inhibitors have been tested in trials for pulmonary neoplasms; however, the underlying mechanisms as well as the clinicopathological relevance of UbcH10 in the genesis and progression of lung cancer remain largely unknown. Therefore, the authors evaluated the expression of UbcH10 in human lung cancer and evaluated its possible diagnostic and prognostic use. They found that most cases of lung adenocarcinoma, squamous cell carcinoma, and large cell and small cell carcinoma were positive for UbcH10. The expression levels of UbcH10 progressively increased with decreasing degree of tumor differentiation. There was a statistically significant difference of UbcH10 positivity between grade I/III of lung adenocarcinoma (p=0.013) and squamous cell carcinoma (p=0.002). No significant differences were found between histological types (p=0.072). In the case of cell blocks prepared from pleural effusions, inflammatory and reactive mesothelial elements did not show appreciable UbcH10 expression, whereas neoplastic cells exhibited clear UbcH10 positivity. The results suggest that UbcH10 might represent a new and promising diagnostic and prognostic marker in both histologic and cytologic specimens of lung cancer.

Value of PAX8 and WT1 Immunostaining in Confirming the Ovarian Origin of Metastatic Carcinoma in Serous Effusion Specimens

We evaluated the detection rates of PAX8 and WT1 immunostaining in 68 (45 as cell blocks, 23 as smears) serous effusion specimens that had a cytologic diagnosis of metastatic carcinoma of ovarian origin. Of the cases, 58 (85%) were positive for PAX8, 56 (82%) were positive for WT1, and 64 (94%) were immunoreactive with either or both markers. Detection rates of PAX8 and WT1 were 85% (44/52) and 92% (48/52), respectively, for metastatic serous carcinoma and 100% (5/5) and 20% (1/5), respectively, for metastatic clear cell carcinoma. Detection rates using cell blocks and smears were 91% and 78%, respectively, with PAX8 and 82% and 83%, respectively, with WT1. We concluded that PAX8 and WT1 had comparable overall detection rates in confirming ovarian origin of malignant effusion. The combination of both markers substantially improved the detection rate. Cell blocks and smears can be used for staining, but a cell block is preferred for PAX8 staining.

Utility of a limited panel of calretinin and Ber-EP4 immunocytochemistry on cytospin preparation of serous effusions: A cost-effective measure in resource-limited settings

Background:

Differentiation between reactive, but morphologically atypical, mesothelial cells and adenocarcinoma in effusions can be problematic. Elaborate immunohistochemical panels have been devised. Techniques like DNA analysis, flow/image cytometry, and K-ras mutation analysis are research oriented and difficult to perform in routine, especially in resource-poor centers. We evaluated the efficacy of a limited two-antibody panel comprising calretinin and Ber-EP4 on cytospin and cell block preparations, in 100 effusion samples.

Materials and Methods:

Fifty cases of reactive mesothelial hyperplasia and 50 cases of adenocarcinoma diagnosed by cytomorphology in ascitic/pleural fluid specimens over a 2-year period were assessed. The diagnoses were confirmed by clinical/histopathologic correlation. Cytospin smears were made in all. Cell blocks were prepared, wherever adequate fluid was available. Immunocytochemistry (ICC) for calretinin and Ber-EP4 was performed.

Results:

Forty-five of the reactive effusion cases (90%) were calretinin reactive and Ber-EP4 negative. Among the adenocarcinoma cases, 49 (98%) were calretinin negative but Ber-EP4 positive. Thus, both calretinin and Ber-EP4 had a high sensitivity (90% and 98%, respectively), as well as a high specificity (100% and 86%, respectively). In the 21 reactive mesothelial cases, whose cell blocks were made, results were comparable to those on cytospin. However, of the 19 adenocarcinoma cases in which cell blocks were prepared, all were Ber-EP4 immunopositive except for three, which were positive on cytospin, implying false-negative results on cell blocks.

Conclusions:

A limited panel of two monoclonal antibodies, calretinin and Ber-EP4, may be useful in cytology, as a “primary antibody panel”, for accurate diagnosis and patient management. Additionally, ICC can be performed easily on cytospin preparations, which gave results comparable to cell blocks in our study.

A review of uncommon cytopathologic diagnoses of pleural effusions from a chest diseases center in Turkey

BACKGROUND

After pneumonia, cancer involving the pleura is the leading cause of exudative pleural effusion. Cytologic examination of pleural effusions is an important initial step in management of malignant effusions. The aim of this study is to evaluate the spectrum of uncommon malignant pleural effusions in a chest disease center in Turkey.

MATERIALS AND METHODS

A retrospective study of samples of pleural effusions submitted to Ataturk Chest Diseases and Chest Surgery Education and Research Hospital Department of Pathology between March 2005 and November 2008 was performed.

RESULTS

Out of a total of 4684 samples reviewed 364 (7.8%) were positive for cancer cells. Of the malignant pleural effusions 295 (81%) were classified as adenocarcinoma or carcinoma not otherwise specified (NOS). Pleural effusion specimens revealing a diagnosis other than adenocarcinoma/carcinoma NOS were: 32 (8.8%) malignant mesotheliomas, 14 (3.8%) small cell carcinomas, 13 (3.5%) hematolymphoid malignancies and 10 (2.7%) squamous cell carcinoma. Hematolymphoid malignancies included non- Hodgkin lymphoma (diffuse B large cell lymphoma, mantle cell lymphoma), multiple myeloma, chronic myeloid leukemia, and acute myeloid leukemia.

CONCLUSIONS

Despite that adenocarcinoma is the most common cause of malignant pleural effusions, there is a significant number of hematological and non-hematological uncommon causes of such effusions. Cytopathologists and clinicians must keep in mind these uncommon entities in routine practice for an accurate diagnosis.

Utility of paired box gene 8 (PAX8) expression in fluid and fine-needle aspiration cytology: an immunohistochemical study of metastatic ovarian serous carcinoma

BACKGROUND

Metastases from ovarian neoplasms are commonly encountered in peritoneal fluids. In addition, reactive mesothelial cells in effusion specimens can mimic ovarian serous carcinoma, making the diagnosis difficult. Calretinin has been recognized as a reliable immunohistochemical marker for mesothelial cells, whereas WT1 has proven useful in the diagnosis of ovarian serous carcinoma. This can present a diagnostic pitfall in effusion cytology, because mesothelial cells can demonstrate immunoreactivity for WT1. Recently, paired box gene 8 (PAX8) has been used in distinguishing ovarian from mammary carcinoma. To the authors' knowledge, no studies using PAX8 have been performed on peritoneal cytology specimens to date, and its expression in metastatic ovarian serous carcinoma has not been studied.

METHODS

These markers, along with BerEP4 and MOC-31, were evaluated in cytology cell block preparations from 30 fluid cytology specimens and 11 fine-needle aspiration specimens.

RESULTS

PAX8 was found to be positive in 37 of 41 (90%) ovarian carcinoma cases studied, and was a sensitive (90%) and specific (100%) marker for the detection of metastatic ovarian carcinoma. In addition, calretinin was found to be useful for identifying mesothelial cells in fluid cytology. Furthermore, although PAX8 and WT1 have demonstrated comparable sensitivity (90% and 93%, respectively) in diagnosing metastatic ovarian carcinoma, PAX8 appears to have superior specificity because staining is not observed in mesothelial cells. BerEP4 and MOC-31 were found to have a lower sensitivity and specificity compared with PAX8.

CONCLUSIONS

PAX8-positive, calretinin-negative staining appears to be highly specific and sensitive for detecting metastatic ovarian serous carcinoma in cytologic preparations and can be useful in distinguishing it from mesothelial cells in fluid cytology.

Occupational toxicology of asbestos-related malignancies

INTRODUCTION

Asbestos is banned in most Western countries but related malignancies are still of clinical concern because of their long latencies. This review identifies and addresses some controversial occupational and clinical aspects of asbestos-related malignancies.

METHODS

Papers published in English from 1980 to 2009 were retrieved from PubMed. A total of 307 original articles were identified and 159 were included.

ASSESSMENT OF EXPOSURE

The retrospective assessment of exposure is usually performed by using questionnaires and job exposure matrices and by careful collection of medical history. In this way crucial information about manufacturing processes and specific jobs can be obtained. In addition, fibers and asbestos bodies are counted in lung tissue, broncho-alveolar lavage, and sputum, but different techniques and interlaboratory variability hamper the interpretation of reported measurements. SCREENING FOR MALIGNANCIES: The effectiveness of low-dose chest CT screening in exposed workers is debatable. Several biomarkers have also been considered to screen individuals at risk for lung cancer and mesothelioma but reliable signatures are still missing. ATTRIBUTION OF LUNG CANCER: Exposures correlating with lung cancer are high and in the same range where asbestosis occurs. However, the unresolved question is whether the presence of fibrosis is a requirement for the attribution of lung cancer to asbestos. The etiology of lung cancer is difficult to define in cases of low-level asbestos exposure and concurrent smoking habits. MESOTHELIOMA: The diagnosis of malignant mesothelioma may also be difficult, because of procedures in sampling, fixation, and processing, and uses of immunohistochemical probes.

CONCLUSIONS

Assessment of exposure is crucial and requires accurate medical and occupational histories. Quantitative analysis of asbestos body burden is better performed in digested lung tissues by counting asbestos bodies by light microscopy and/or uncoated fibers by transmission electron microscopy. The benefits of screenings for asbestos-related malignancies are equivocal. The attribution of lung cancer to asbestos exposure is difficult in a clinical setting because of the need to assess asbestos body burden and the fact that virtually all these patients are also tobacco smokers or former smokers. Given the premise that asbestosis is necessary to causally link lung cancer to asbestos, it follows that the assessment of both lung fibrosis and asbestos body burden is necessary.

Mesothelial proteins are expressed in the human cornea

The goal of our study was to determine whether proteins typical of the human mesothelial cell phenotype, such as mesothelin, HBME-1 (Hector Battifora mesothelial cell-1) protein and calbindin 2, are expressed in the human cornea, especially in endothelial cells. Cryosections and endothelial and epithelial imprints of sixteen human cadaverous corneoscleral discs were used. The presence of proteins was examined using immunohistochemistry and Western blotting, while mRNA levels were determined by qRT-PCR. A strong signal for mesothelin was present in the corneal epithelium, while less intense staining was visible in the endothelium. Similarly, higher and lower mRNA levels were detected using qRT-PCR in the corneal epithelium and endothelium, respectively. HBME-1 antibody strongly stained the corneal endothelium and stromal keratocytes. Marked positivity was present in the corneal stromal extracellular matrix, while no staining was present in the sclera. Calbindin 2 was detected using immunohistochemistry and Western blotting in the corneal epithelium, endothelium and stroma. qRT-PCR confirmed its expression in epithelial and endothelial cells. Three proteins expressed constitutively in mesothelial cells were detected in the human cornea. The possible function of mesothelin in cell-cell contact on the ocular surface is discussed. The presence of HBME-1 protein in the endothelial layer may indicate a still unknown function that could be shared with mesothelial cells of the pleura and peritoneum. The much more pronounced occurrence of calbindin 2 in the corneal epithelium compared to fewer positive endothelial cells explains the higher turnover of epithelial cells compared to the proliferatively inactive endothelium.

Challenges in the interpretation of peritoneal cytologic specimens

CONTEXT

The presence of malignant cells in peritoneal washings leads to classification as International Federation of Gynecology and Obstetrics stage IC or higher in ovarian carcinomas and at least International Federation of Gynecology and Obstetrics stage IIIA in endometrial carcinomas. Unfortunately, the morphologic examination of cytologic specimens has not proven to be a sensitive or specific diagnostic tool. Malignant cells might be few in number and might be unrecognized among a large population of mesothelial cells and/or macrophages, or reactive mesothelial cells might be misinterpreted as neoplastic cells leading to unnecessary chemotherapy.

OBJECTIVE

To evaluate the main pitfalls in the evaluation of peritoneal washings in patients with gynecologic malignancies and analyze the ancillary studies that might be helpful to achieve the correct diagnosis with an emphasis on immunocytochemistry.

DATA SOURCES

A comprehensive review of the literature was performed.

CONCLUSIONS

Peritoneal effusions may represent major challenges to the pathologist and can have important clinical implications. Immunostains for epithelial markers such as B72.3, MOC-31, and Ber-EP4 represent the best available markers to identify epithelial cells. Caution is advised to not overdiagnose endometriosis or endosalpingiosis as adenocarcinoma.

Immunocytochemical panel for distinguishing between adenocarcinomas and reactive mesothelial cells in effusion cell blocks

The aim of our study was to determine the value of a panel that consisted of one epithelial marker (MOC-31) and two mesothelial markers (D2-40 and calretinin) for distinguishing between reactive mesothelial cells (RMCs) and adenocarcinomas (ACs) in effusion fluids. A total of 118 cell block specimens from pleural and peritoneal effusions, including 88 ACs and 30 benign effusions with RMCs were stained with antibodies against MOC-31, D2-40, and calretinin. MOC-31 membranous activity was observed in all samples from ACs, regardless of the primary tumor site. All benign effusion samples with RMCs were negative for MOC-31. All benign effusion samples with RMCs exhibited membranous staining for D2-40, and one AC case had focal reactivity for D2-40. Almost all benign effusions reacted positively with calretinin. Staining was noted in both the cytoplasm and the nucleus in the majority of cases. Scattered tumor cells had weak calretinin positivity in two AC cases. Background RMCs in AC effusions were consistently positive for D2-40 and calretinin. In general, D2-40 identified more RMCs than calretinin. The staining combination of positive for MOC-31 and negative for D2-40 or calretinin were 100% specific and 99% sensitive for ACs. Our data suggest that immunohistochemical studies performed on cell blocks with MOC-31, D2-40, and calretinin were useful in the differentiation between ACs and RMCs. D2-40 was a more sensitive marker for RMCs than calretinin.

Immunocytochemical panel for distinguishing carcinoma cells from reactive mesothelial cells in pleural effusions

OBJECTIVE

The aim of this study was to evaluate the individual and combined diagnostic utility of carcinoembryonic antigen (CEA), cytokeratin 19 fragments (CK19) and HBME-1 in pleural effusions of patients with lung cancer.

STUDY DESIGN

CEA, CK19 and HBME-1 were detected by immunocytochemistry in pleural effusions from patients with lung cancer (86 cases) and without lung cancer (40 cases).

RESULTS

CEA and CK19 expression were significantly higher in the carcinoma cell group and in three subgrouped as adenocarcinoma (AC), squamous cell carcinoma (SCC) and small cell lung cancer than in the mesothelial cell group, whereas HBME-1 expression was lower in the former group (P < 0.01). In the subgrouped tumours, CEA expression was higher in AC than in SCC (P < 0.05), whereas HBME-1 expression was higher in SCC than in AC (P < 0.01). Used alone, CK19 had the highest sensitivity (95.3%) and accuracy (93.7%), whereas CEA had the highest specificity (97.5%). When combinations of antibodies were evaluated together and membrane staining with HBME-1 taken as a negative outcome, CK19 and HBME-1 gave a high diagnostic performance: sensitivity of 100.0% and accuracy of 95.2% respectively.

CONCLUSION

A panel of CEA, CK19 and HBME-1 monoclonal antibodies proved to be suitable for distinguishing carcinoma cells from reactive mesothelial cells in pleural effusions.

Losses of chromosome arms 4q, 8p, 13q and gain of 8q are correlated with increasing chromosomal instability in hepatocellular carcinoma

OBJECTIVE

Chromosomal instability is a key feature in hepatocellular carcinoma (HCC). Array comparative genomic hybridization (aCGH) revealed recurring structural aberrations, whereas fluorescence in situ hybridization (FISH) indicated an increasing number of numerical aberrations in dedifferentiating HCC. Therefore, we examined whether there was a correlation between structural and numerical aberrations of chromosomal instability in HCC.

METHODS AND RESULTS

27 HCC (5 well, 10 moderately, 12 lower differentiated) already cytogenetically characterized by aCGH were analyzed. FISH analysis using probes for chromosomes 1, 3, 7, 8 and 17 revealed 1.46-4.24 signals/nucleus, which correlated with the histological grade (well vs. moderately,p < 0.0003; moderately vs. lower, p < 0.004). The number of chromosomes to each other was stable with exceptions only seen for chromosome 8. Loss of 4q and 13q, respectively, were correlated with the number of aberrations detected by aCGH (p < 0.001, p < 0.005; Mann-Whitney test). Loss of 4q and gain of 8q were correlated with an increasing number of numerical aberrations detected by FISH (p < 0.020, p < 0.031). Loss of 8p was correlated with the number of structural imbalances seen in aCGH (p < 0.048), but not with the number of numerical changes seen in FISH.

CONCLUSION

We found that losses of 4q, 8p and 13q were closely correlated with an increasing number of aberrations detected by aCGH, whereas a loss of 4q and a gain of 8q were also observed in the context of polyploidization, the cytogenetic correlate of morphological dedifferentiation.

Claudin 4 identifies a wide spectrum of epithelial neoplasms and represents a very useful marker for carcinoma versus mesothelioma diagnosis in pleural and peritoneal biopsies and effusions

We evaluated the usefulness of the tight-junction associated protein Claudin 4 (CL-4) in the diagnosis of mesothelioma and mimickers, analyzing biopsies from 454 tumors, including 82 mesotheliomas, 336 carcinomas of different origin (278 primary, 58 metastatic to serosae), 36 nonepithelial spindle cell neoplasms, as well as 97 cytological samples from reactive effusions (12), mesothelioma (23) and metastatic carcinomas (62). CL-4 was consistently negative in normal and reactive mesothelium, as well as in all 82 mesotheliomas. In contrast, strong reactivity was found in 57/58 serosal metastasis, and in 245/278 primary carcinomas, with uppermost expression (150/153) in those most frequently involved in the differential with mesothelioma (lung, breast, gastrointestinal tract, pancreas, ovary, primary serous papillary carcinoma of peritoneum). On effusions, reactive and neoplastic mesothelial cells were regularly negative, while metastatic tumor cells stained positively in 60/62 (96.8%) cases. Among spindle cell neoplasms, only 2/9 biphasic synovial sarcomas and 4/4 follicular dendritic cell sarcomas stained positively. Results indicate that CL-4 reacts with the majority of epithelial neoplasms that often metastasize to serous membranes, representing a pancarcinoma marker with extremely high sensitivity and specificity. CL-4 may be considered a primary immunohistochemical reagent to rule out the diagnosis of mesothelioma.

[Immunocytochemistry in malignant serous effusions]

Immunocytochemistry may be of valuable help in typing most malignant serous effusions. Various preparatory methods are described including centrifugation and smearing, cytocentrifugation, cell blocks and liquid based cytology. The value and usefulness of immunocytochemistry depends on the experience of each pathologist. The use of a panel of antibodies associating markers of carcinomas with markers of mesothelial cells is recommended.

The utility of fluorescence in-situ hybridization in the diagnosis of malignant pleural effusion

PURPOSE OF REVIEW

Molecular tools are used to refine the diagnosis of malignancy in pleural fluids. This review discusses the rationale and recent findings of the application of one of these tools, fluorescence in-situ hybridization, in pleural effusions.

RECENT FINDINGS

Aneuploidy (i.e., pronounced numeric and structural chromosomal changes) is a recurrent finding in cells of solid tumors. Different methods attempt to detect tumor-associated aneuploidy to prove micrometastasis in different compartments, such as urine, cerebrospinal fluid, bone marrow, and body fluids. In recent years, fluorescence in-situ hybridization analysis has proved viable for detecting metastasis based on the observation of matching patterns of chromosomal aneusomies in primary tumors and corresponding metastasis.

SUMMARY

Fluorescence in-situ hybridization analysis using specific probes for visualizing numeric aberrations in a microscopic evaluation (thus complementing routine cytologic evaluation) has been shown to be relatively simple, very robust, and thus applicable in material of lesser quality and more sensitive than routine cytology. Remarkably, dual-color fluorescence in-situ hybridization analysis allows for an efficient analysis in effusions, and the approach presented in this review proved to be more specific than other molecular procedures applied in effusions to detect malignancy, such as polymerase chain reaction. Prospective studies are needed to demonstrate that refinement of staging by fluorescence in-situ hybridization or polymerase chain reaction ('molecular upstaging') will translate into meaningful therapeutic consequences.

TNF-alpha promotes progression of peritoneal metastasis as demonstrated using a green fluorescence protein (GFP)-tagged human gastric cancer cell line

The mechanisms underlying progression of peritoneal metastasis by gastric cancer after micrometastasis formation remain unclear. In the present study, we investigated metastasis to the abdominal wall peritoneum, one of the major features of peritoneal spread, using a human gastric cancer cell line (GCIY-EGFP) tagged with the green fluorescence protein gene (GFP). This model allows sensitive, specific and sequential observation of metastasis development from the initial deposits to peritoneal carcinomatosis at the end stage. In the initial phase, GCIY-EGFP cells could form micrometastasis selectively on the omentum and mesenterium in a milky spot-dependent manner, but not on abdominal wall peritoneum lacking milky spots until the late stages. In vitro analysis using primary mesothelial cells revealed addition of TNF-alpha to decrease their stress fibers, leading to morphological change followed by exposure of the submesothelial extracellular matrix (ECM) in intercellular gaps. Such TNF-alpha pretreatment was found to enhance attachment of tumor cells to the mesothelial monolayer. When tumor cells were injected into the peritoneal cavity of TNF-alpha pretreated mice, they could metastasize to the abdominal wall peritoneum from the very early stages, resulting in accelerated accumulation of ascites than in TNF-alpha non-pretreatment controls. RT-PCR analysis revealed that tumor cells express cytokines and chemokines, including TNF-alpha. Furthermore, TNF-alpha treatment results in up-regulation of expression of monocyte chemoattractant protein-1 (MCP-1) and IL-8 by mesothelial cells and of TNF-alpha itself by inflammatory leukocytes in the peritoneal cavity. These results suggest that metastasis to the abdominal wall peritoneum occurs as a second step from the first omental metastasis in a milky spot-independent manner and that TNF-alpha derived from tumor cells, mesothelial cells and inflammatory leukocytes in the peritoneal cavity may be involved in the progression of peritoneal metastasis.

E-cadherin and calretinin as immunocytochemical markers to differentiate malignant from benign serous effusions

AIM: To investigate the expressions of E-cadherin and calretinin in exfoliated cells of serous effusions and evaluate their values in distinguishing malignant effusions from benign ones.

METHODS: Fresh serous effusion specimens were centrifuged and exfoliated cells were collected. Cells were then processed with a standardized procedure, including paraformaldehyde fixation, BSA-PBS solution washing and smears preparation. E-cadherin and calretinin were detected by immunocytochemistry (ICC).

RESULTS: In the exfoliated cells of serous effusions, most of carcinoma cells only expressed E-cadherin, and most of mesothelial cells only expressed calretinin, and benign cells (lymphocytes and granulocytes) did not express either of them. For E-cadherin, 85.7% (30/35) of malignant effusions and 8.1% (3/37) of benign fluids were ICC-positive (P < 0.001). The sensitivity of E-cadherin ICC in the diagnosis of malignant effusions was 85.7%, specificity 91.9%, and diagnostic rate 88.9%. For calretinin, 94.6% (35/37) of benign effusions and 11.4% (4/35) of malignant effusions were ICC-positive (P < 0.001). The sensitivity of calretinin ICC in the diagnosis of benign effusions was 94.6%, specificity 88.6%, and diagnostic rate 91.7%. For diagnosis of benign and malignant effusions by combining E-cadherin ICC and calretinin ICC, the specificities were up to 100% and 97.1%, respectively.

CONCLUSION: E-cadherin ICC and calretinin ICC are sensitive and specific in differential diagnosis of benign and malignant serous effusion specimens and specificities are evidently improved when both markers are combined.

Serous effusions: diagnosis of malignancy beyond cytomorphology. An analytic review

In this brief review, the role of various ancillary techniques to detect malignancy in effusion fluid are evaluated and discussed. The data were collected from a large number of research articles published in various medical journals. The role of these techniques to increase the diagnostic accuracy in serous effusions is emphasised.