Cytologic diagnosis of malignant mesothelioma in serous effusions using an antimesothelial-cell antibody.

Differentiating mesothelioma, reactive mesothelium, and adenocarcinoma in serous effusions is often difficult, despite the application of ancillary techniques in support of the traditional cytomorphologic criteria. A polyclonal antimesothelial-cell antibody recently developed by our group was evaluated as a histogenetic marker on a series of primary (n = 12) and metastatic (n = 12) malignant effusions. Immunostaining was performed on paraffin sections from cell blocks. All mesothelioma effusions stained positive for the antibody, whereas, in contrast, all metastatic carcinoma specimens failed to react. These results (100 percent specificity and 100% sensitivity for mesothelioma) provide a basis for a reliable use of the antibody in the cytologic examination of suspicious or malignant serous effusions.     

Culture of menstrual endometrium with peritoneal explants and mesothelial monolayers confirms attachment to intact mesothelial cells

BACKGROUND: To evaluate adhesion of menstrual endometrium (ME) to intact peritoneal mesothelium. METHODS: Explants of peritoneum were cultured for 1 h with ME (n = 6). Specimens were serially sectioned for haematoxylin and eosin stain and immunohistochemistry using an anti-cytokeratin antibody to label mesothelium. Confocal laser scanning microscopy (CLSM) was performed to identify an intact layer of mesothelial cells (MC) underlying sites of ME attachment. Also, ME and MC were labelled with Cell-Tracker dyes. ME was cultured with mesothelial monolayers for 1 h (n = 10). Cultures were examined with differential interference contrast and CLSM. Optical sections were taken and a three-dimensional model was constructed. RESULTS: In the peritoneal explants, ME adhered to intact mesothelium. There was no evidence of transmesothelial invasion. CLSM of sections of the explants demonstrated an intact monolayer of cytokeratin positive cells below the sites of ME implantation. Cytokeratin negative and positive ME cells adhered to mesothelial cells. Likewise, the ME attached to cultured mesothelium. Orthogonal sections and three-dimensional reconstruction confirmed an intact monolayer of mesothelium underlying ME attachment sites. CONCLUSIONS: This study confirms that ME adheres rapidly to intact peritoneal mesothelium. Further studies are needed that characterize the mechanisms of ME adhesion to, and migration through, mesothelial cells.     

Morphological changes in mesothelial cells induced by shed menstrual endometrium in vitro are not primarily due to apoptosis or necrosis

In a previous study on the pathogenesis of endometriosis, we observed that constituents of menstrual effluent induce morphological alterations in human mesothelial cells. In this study, we investigated whether these alterations were associated with apoptosis or necrosis or were the result of cellular remodelling. After overnight incubation of confluent monolayers of human omental mesothelial cells (HOMEC) with conditioned media prepared from menstrual effluent shed anterogradely, severe alterations in morphology were observed. Typical polygonal mesothelial cell cultures at confluency acquired elongated spindle morphology, resulting in gaps between the cells. In contrast, mesothelial cells from the control groups receiving culture medium only, retained a normal morphology. Immunofluorescence staining revealed that cytokeratin, vimentin and actin filaments were still present, homogeneously distributed in the cell cytoplasm following changes in morphology. To evaluate whether the morphological alterations were associated with apoptosis and/or necrosis, the cells were stained with the M30 CytoDeath antibody or annexin V with propidium iodide and analysed using flow cytometry. The results showed that only a small percentage (1-7%) of the affected HOMEC were undergoing apoptosis or necrosis. We conclude that the profoundly altered morphology of HOMEC is a result of cellular remodelling and that the role of apoptosis and necrosis is negligible. Soluble paracrine factors released by cells isolated from menstrual effluent shed anterogradely may induce a reorganization of the cytoskeleton. As a result, the underlying basement membrane will be exposed and the mesothelium may no longer prevent implantation of endometrium shed retrogradely into the peritoneum, thus facilitating the development of endometriosis.     

大鼠膈腹膜间皮通透性的电镜观察

腹膜腔内注射兔血液和中墨汁后，用电镜观察了大鼠膈腹膜间皮对示踪剂血细胞和碳颗粒的通透笥。在膈膜隐窝区，示踪剂经三种途径通过膈腹膜间皮。（１）间皮孔的吸收作用。示踪剂由腹膜腔经间皮孔直接进入膈毛细淋巴管，或被成纤维细胞的突起包绕。（２）间皮细胞的吞噬作用。（３）示踪剂通过间皮细胞间裂隙或细胞间连接。     

联合检测E-cadherin、CEA及Calretinin在浆膜腔积液细胞学鉴别诊断中的意义

背景与目的：浆膜腔积液中转移性腺癌细胞、恶性上皮型间皮瘤细胞和反应性间皮细胞的形态有不少相似之处，有时仅凭形态学特征不能做出准确诊断。近年来免疫细胞化学在这方面得到较多应用，但国内报道仅局限于用CK、EMA、CEA、Vim和HBME-1几种抗体，而且不能较好地进行细胞学的鉴别诊断。本研究旨在探讨联合检测E-cadherin、CEA及calretinin在浆膜腔积液鉴别诊断中的应用价值。方法：选用浆膜腔积液标本共93例，其中胸水66例、腹水24例、心包积液3例。经组织学检查或结合临床资料证实的转移性腺癌55例、恶性上皮型间皮瘤6例、间皮细胞反应性增生32例。每例均制备HE染色的涂片和细胞块，并用细胞块切片作免疫细胞化学染色。结果：E-cadherin、CEA对诊断转移性腺癌的敏感性分别为85．5％(47／55)、78．2％(43／55)，特异性分别为100％(38／38)、97．4％(37／38)。E-cadherin和CEA联合应用诊断浆膜腔积液转移性腺癌的阳性率为96．4％(53／55)。Calretinin对诊断间皮瘤和间皮细胞增生的敏感性和特异性分别为81.6％(31／38)和87．2％(48／55)。结论：E-cadherin、CEA和calretinin是鉴别浆膜腔积液转移性腺癌细胞和间皮源性细胞有价值的一组抗体。     

Diagnostic mesothelioma biomarkers in effusion cytology

Malignant mesothelioma is a rare malignancy with a poor prognosis whose development is related to asbestos fiber exposure. An increasing role of genetic predisposition has been recognized recently. Pleural biopsy is the gold standard for diagnosis, in which the identification of pleural invasion by atypical mesothelial cell is a major criterion. Pleural effusion is usually the first sign of disease; therefore, a cytological specimen is often the initial or the only specimen available for diagnosis. Given that reactive mesothelial cells may show marked atypia, the diagnosis of mesothelioma on cytomorphology alone is challenging. Accordingly, cell block preparation is encouraged, as it permits immunohistochemical staining. Traditional markers of mesothelioma such as glucose transporter 1 (GLUT1) and insulin-like growth factor 2 mRNA-binding protein 3 (IMP3) are informative, but difficult to interpret when reactive proliferations aberrantly stain positive. BRCA1-associated protein 1 (BAP1) nuclear staining loss is highly specific for mesothelioma, but sensitivity is low in sarcomatoid tumors. Cyclin-dependent kinase inhibitor 2A (CDKN2A)/p16 homozygous deletion, assessed by fluorescence in situ hybridization, is more specific for mesothelioma with better sensitivity, even in the sarcomatoid variant. The surrogate marker methylthioadenosine phosphorylase (MTAP) has been found to demonstrate excellent diagnostic correlation with p16. The purpose of this review is to provide an essential appraisal of the literature regarding the diagnostic value of many of these emerging biomarkers for malignant mesothelioma in effusion cytology.     

Extrathoracic Mesothelial Proliferations and Their Mimics

Mesothelial proliferations, either reactive or neoplastic in nature, often pose difficult diagnostic dilemmas. Electron microscopy continues to be a gold standard in the identification of mesothelial differentiation. However, it is very common to apply long panels of antibodies for that purpose. In most cases, light microscopy and immunohistochemistry will solve the problem. However, the definitive, specific, and sensitive immunohistochemical marker is still lacking. This is particularly true in peritoneal and testicular mesothelial tumors, in which common embryologic origin with epithelial elements results in overlapping immunohistochemistry and morphology. The particularities of peritoneal and testicular mesothelial proliferations, and the main tumors that may mimic them in these sites, as well as the value and limitations of immunohistochemistry and electron microscopy in their differential diagnosis are the subject of this review.     

Mesothelial cells: their structure,function and role in serosal repair

The mesothelium is composed of an extensive monolayer of specialized cells (mesothelial cells) that line the body's serous cavities and internal organs. Traditionally, this layer was thought to be a simple tissue with the sole function of providing a slippery, non-adhesive and protective surface to facilitate intracoelomic movement. However, with the gradual accumulation of information about serosal tissues over the years, the mesothelium is now recognized as a dynamic cellular membrane with many important functions. These include transport and movement of fluid and particulate matter across the serosal cavities, leucocyte migration in response to inflammatory mediators, synthesis of pro-inflammatory cytokines, growth factors and extracellular matrix proteins to aid in serosal repair, release of factors to promote both the deposition and clearance of fibrin, and antigen presentation. Furthermore, the secretion of molecules, such as glycosaminoglycans and lubricants, not only protects tissues from abrasion, but also from infection and possibly tumour dissemination. Mesothelium is also unlike other epithelial-like surfaces because healing appears diffusely across the denuded surface, whereas in true epithelia, healing occurs solely at the wound edges as sheets of cells. Although controversial, recent studies have begun to shed light on the mechanisms involved in mesothelial regeneration. In the present review, the current understanding of the structure and function of the mesothelium and the biology of mesothelial cells is discussed, together with recent insights into the mechanisms regulating its repair.     

Iron overload in the peritoneal cavity of women with pelvic endometriosis

OBJECTIVE: To examine the possible involvement of iron in the physiopathology of endometriosis. DESIGN: Prospective study. SETTING: Department of gynecology in a university hospital. PATIENT(S): Seventy patients undergoing laparoscopy. INTERVENTION(S): Collection of peritoneal fluid (n = 57), blood samples, and biopsy samples from endometrium (n = 62) and from endometriotic (n = 33) and normal-appearing peritoneum (n = 53). MAIN OUTCOME MEASURE(S): Measurement of iron and ferritin in serum and peritoneal fluid and staining of iron deposits with Prussian blue in tissues. RESULT(S): Iron and ferritin concentrations were significantly higher in the peritoneal fluid of patients with endometriosis compared with controls during the secretory phase. Higher rates of ferritin and hemosiderin deposits were observed in the peritoneum adjacent to red (100%), black (57%), and white (62%) lesions compared with normal-appearing peritoneum (25%). Deposits were more frequent during the secretory phase than the proliferative phase in healthy peritoneum from controls, whereas they were found throughout the cycle in the vicinity of lesions in patients with endometriosis. Similar rates of iron deposition were observed in the stroma of black and white lesions and in eutopic endometrium from patients with endometriosis. CONCLUSION(S): Iron overload was observed in the cellular and peritoneal fluid compartments of the peritoneal cavity of women with endometriosis. Iron deposits seem to be related to the presence of lesions, suggesting that iron may be involved in the pathogenesis of endometriosis.     

The alpha(2)beta(1) and alpha(3)beta(1) integrins do not mediate attachment of endometrial cells to peritoneal mesothelium

OBJECTIVE: To evaluate the possible role of mesothelial alpha(2)beta(1) and alpha(3)beta(1) integrins in the attachment of endometrial stromal cells (ESCs) and endometrial epithelial cells (EECs). DESIGN: In vitro study. SETTING: University medical center. PATIENT(S): Women of reproductive age (n = 26). MAIN OUTCOME MEASURE(S): Mesothelial cells were grown on collagen IV. Endometrial stromal cells and EECs were plated on mesothelial cells for 1 hour. Before plating, mesothelial cells or endometrial cells were incubated with antibodies to alpha2, alpha3, and beta1 integrin subunits. The effect of these antibodies on ESC and EEC binding to collagen IV and collagen I was also examined. The expression of collagen I, collagen IV, fibronectin, and laminin by cultured ESCs and EECs was examined. RESULT(S): The anti-integrin antibodies had no effect on endometrial binding to mesothelium. The beta1 integrin antibody decreased binding of ESCs and EECs to the collagen matrices. In culture, ESCs and EECs expressed collagen I, collagen IV, fibronectin, and laminin to varying degrees. CONCLUSION(S): The initial adhesion of ESCs and EECs to mesothelium is not mediated by beta1 integrins. In contrast, ESC and EEC attachment to collagen IV and collagen I, which are present in the submesothelial extracellular matrix, is mediated by beta1 integrins.