Malignant pleural mesothelioma and epidermal growth factor receptor (EGF-R). Relationship of EGF-R with histology and survival using fixed paraffin embedded tissue and the F4, monoclonal antibody.

The expression of epidermal growth factor receptor (EGF-R) in 34 formalin fixed paraffin embedded specimens of malignant mesothelioma was examined using the F4 antibody. Eight samples of reactive pleura showed homogenous cytoplasmic staining with the antibody. EGF-R positive cells (greater than or equal to 5%) were found in 68% of the mesotheliomas examined. EGF-R positivity was more commonly seen in the epithelial histological subtype than in the sarcomatous or mixed subtypes. Patients with less than 5% of mesothelioma cells staining positive for EGF-R had a significantly shorter survival (median 299 days) compared with patients whose tumours had a greater number of cells positive for EGF-R (median 446 days) (P = 0.04). However, when the histological subgroup was also taken into consideration (epithelial type had a significantly longer survival than the sarcomatous or mixed) the survival difference in relation to EGF-R positivity was no longer significant (P = 0.08). EGF-R could not be used to distinguish between malignant and benign mesothelial tissue and was not an independent prognostic factor for survival.

Reactive lesions of the pleura. Immunohistochemical characterization.

The visceral pleura of 8 lung tissue specimens with non-tumorous pleural lesions and of 10 specimens with secondary pleural infiltration of different primary tumours were tested by avidin-biotin-method with the following antibodies: anti-keratin KL1, anti-vimentin V9, anti-CEA (BMA 130c), HEA 125, Leu M1, HMFG 2 and anti-collagen type IV. In all cases anti-keratin positive subserosal cells could be proved. Activated mesothelial cells expressed vimentin additionally to keratin. The antibodies Leu M1, HEA 125 and BMA 130c (against CEA) showed no reaction in subserosal and mesothelial cells. With the antibody HMFG 2, however, a weak reaction could be observed. A distinction between reactive and neoplastic pleural lesions is not possible by using these antibodies. The antibodies LeuM1, HEA 125 and BMA 130c can be helpful for differential diagnosis in single cases with pleural carcinosis. The antibody against collagen type IV demonstrates newly developed basal membrane structures in areas with proliferating subserosal cells. Considering our results the entity of mesothelium and submesothelium is discussed with regard to the histogenetical aspect of mesothelioma.

[Malignant mesothelioma of the pleura. Analysis of its immunohistochemical aspects]. / Mésothéliomes malins de la plèvre. Analyse de leurs aspects immunohistochimiques.

To evaluate the usefulness of immunohistochemistry in the diagnostic distinction between pleural mesothelioma and metastatic adenocarcinoma to the pleura, the authors studied formalin-fixed paraffin-embedded tissue sections from 14 pleural mesotheliomas and 20 primary adenocarcinomas of the lung, stomach, ovary and breast by using 16 commercially available antibodies to cytokeratin (KL1), vimentin, EMA, CEA, CA19.9, CA125, Egp 34 (detected by HEA 125), secretory component, S100 protein, SP1-béta 1, Leu M1, alpha-1-AT, alpha-1-ACT, lysozyme, desmin and factor VIII. Keratin positivity was found in all mesotheliomas and adenocarcinomas. A coexpression of keratin and vimentin was present in 8/14 (57%) mesotheliomas but only in 2/20 (10%) adenocarcinomas. CEA and CA 19.9 were detected in 80% and 65% of the adenocarcinomas respectively, but not in any of the mesotheliomas. Interestingly, two adenocarcinomas (of the ovary and the stomach) that failed to stain for CEA, were immunoreactive to anti-CA 19.9 antibody. Thus, the combined use of anti-CEA and anti-CA 19.9 antibodies results in staining 90% of the adenocarcinomas. S100 protein, SP1-beta and Leu M1 were also absent in mesotheliomas but present only in less than half of the adenocarcinomas. Adenocarcinomas and mesotheliomas did not significantly vary in reaction to the remaining above mentioned antibodies. The authors conclude that the coexpression of keratin and vimentin and the absence of CEA and CA 19.9 might be the best criteria in the distinction of mesothelioma from metastatic non mucosecreting adenocarcinoma.

[Benign pleural fibroma. An anatomo-clinical study of 10 cases]. / Les fibromes pleuraux bénins. Etude anatomo-clinique de 10 cas.

We present an anatomical-clinical analysis of ten cases of benign pleural fibroma. This tumour was discovered in a systematic fashion in 8 of the 10 cases and fortuitously in one. Recent radiological examinations enabled the diagnosis to be suspected. Computerised tomography most often precisely identified the pleural topography and imagery by nuclear magnetic resonance in one case visualised fibrous tissue (with a zone of low signals on the scale in T2). The final diagnosis was achieved at the same time as the treatment when an exploratory thoracotomy was performed. In all the cases there was a tumour composed of fusiform cells covered by normal epithelium coming from the viscera pleura 8 times out of 10. The ultrastructure examination and immunohistochemistry of the fusiform cells (Vimentin plus, EMA-, KL1-) allowed for a differentiation of these tumours of connective tissue origin from tumours of mesothelial origin. These analyses constitute an argument in favour of the fibroblastic origin of pleural fibromas.

Immunohistochemical analysis of pulmonary and pleural neoplasms with monoclonal antibodies B72.3 and CSLEX-1.

Sequential paraffin sections of 222 epithelial lung tumors comprising all common histologic types, and 31 pleural mesotheliomas of all variants were immunostained with monoclonal antibodies (Mabs) B72.3 and CSLEX-1. Reactivity with Mabs B72.3 and CSLEX-1 respectively was noted in 7/57 and 4/57 squamous carcinomas, in 44/70 and 60/70 adenocarcinomas, 9/16 and 11/16 bronchioloalveolar carcinomas, 8/25 and 14/25 large cell undifferentiated carcinomas, 3/3 and 3/3 adenosquamous carcinomas, 0/11 and 0/11 carcinoids, 0/10 and 2/10 well differentiated neuroendocrine (NE) carcinomas, 4/13 and 5/13 intermediate cell NE carcinomas, 0/17 and 0/17 small cell NE carcinomas, and 0/31 and 1/31 mesotheliomas. In most instances, both Mabs stained the same tumors; however, reactivity with CSLEX-1 was more intense and extensive, and involved more cases. Therefore, regardless of conventional histologic type, staining with Mabs B72.3 and CSLEX-1 defines 4 subsets of lung tumors: one expressing both antigens, two expressing one but not the other, and one expressing neither. The possible biological and/or clinical significance of these subsets remains undetermined. When correlated with conventional histologic tumor types, our findings indicate: 1). both of these Mabs recognize most but not all adenocarcinomas and bronchioloalveolar carcinomas, and since CSLEX-1 stained more cases than B72.3, it may be argued that the former is a broader exocrine phenotype marker than the latter; 2). both of these Mabs select exocrine subsets of large cell undifferentiated carcinomas; 3). both of these Mabs stain exocrine cell subpopulations in well differentiated and intermediate cell NE carcinomas but not in carcinoids or small cell NE carcinomas, and 4). except for rare cases, neither B72.3 nor CSLEX-1 reacts with mesotheliomas regardless of variant.(ABSTRACT TRUNCATED AT 250 WORDS)

Localized fibrous tumor of the serosal cavities. Immunohistochemical, electron-microscopic, and flow-cytometric DNA study.

Localized fibrous tumor of the serosal cavities (localized fibrous mesothelioma) is a generally benign spindle cell neoplasm of uncertain histogenesis. Fourteen histologically similar primary tumors from different mesothelium-lined sites (11 pleural and 1 each in the pericardium, peritoneal cavity, and pouch of Douglas) and 2 recurrences of those tumors (pericardium and pouch of Douglas) were examined histopathologically and by flow cytometry to relate histologic features and DNA ploidy to biologic behavior (follow-up, 48-255 months among 13 patients). All 16 tumors (14 primaries and 2 recurrences) displayed diploid DNA pattern, and none of 13 patients died of disease (1 patient was lost to follow-up). To elucidate the histogenesis, seven primary tumors were examined for vimentin and keratin immunostaining and six primary tumors were assessed by electron microscopy. All cases exhibited spindle-fibroblastic cell proliferation with a prominent hemangiopericytic pattern. All cases so examined had positive results for vimentin and negative results for keratin. Ultrastructurally, the tumor cells showed mesenchymal-fibroblastic features. These results support a mesenchymal origin, most likely from submesothelial fibroblasts. Further, this neoplasm may recur but retain its basic histologic features, diploidy, and benign outcome.

Immunohistochemical differentiation of sarcomatoid mesotheliomas from other spindle cell neoplasms.

A sizable proportion of pleural malignant mesotheliomas are sarcomatoid (22%) or biphasic (24%) and may need to be distinguished from other spindle cell neoplasms that occur as primary or metastatic tumors of the chest wall or lungs. To determine the utility of immunohistochemistry in the differentiation of sarcomatoid malignant mesotheliomas from other spindle cell neoplasms, the authors studied the immunostaining patterns of nine antibodies in four sarcomatoid mesotheliomas, one desmoplastic mesothelioma, two epithelial mesotheliomas, four spindle cell squamous carcinomas, and eight sarcomas of various differentiation. Three of the four sarcomatoid mesotheliomas and the desmoplastic mesothelioma had positive results for cytokeratin, which distinguishes them from sarcomas but not from spindle cell squamous carcinomas. The immunostaining pattern of 14 examples of benign spindle cell mesothelial proliferation was similar to that of the sarcomatoid mesotheliomas, which supports the theory that these tumors are mesothelial in origin. Although other antibodies occasionally may be helpful, depending on the differentiation of the sarcoma, cytokeratin immunostaining appears to be the best method to discriminate sarcomatoid mesotheliomas from sarcomas.

Sarcomatous tumor of the chest wall with osteochondroid differentiation. Evidence of mesothelial origin.

We describe a case of sarcomatous tumor of the chest wall with differentiation toward bone and cartilage that was observed in an asbestos-exposed worker. Although the mesothelial nature of the tumor was at first considered, it was not proven. Later, the tumor was shown to be a mesothelioma using a panel of pertinent antibodies that included a recently described anti-mesothelial cell marker. In addition, asbestos bodies were found in association with the sarcoma cells. Our findings indicate that whenever physicians encounter any type of primary sarcomatoid tumor involving serous membranes, the possibility of malignant mesothelioma should be regarded a priori.

The immunohistochemical diagnosis of mesothelioma. Differentiation of mesothelioma and lung adenocarcinoma.

Despite numerous histochemical, ultrastructural, and immunohistochemical studies, differentiation between malignant epithelial pleural mesothelioma and adenocarcinoma of the lung remains extremely difficult. Although there is general agreement that immunohistochemical methods can aid in this distinction, some studies have produced conflicting results with some of the proposed markers for mesothelioma. To obtain comparable and reproducible results, 19 unequivocal epithelial mesotheliomas and 23 unequivocal primary lung adenocarcinomas were studied by the avidin-biotin-peroxidase complex method on formalin-fixed, paraffin-embedded tissue specimens. Well-characterized, commercially available antibodies to carcinoembryonic antigen (CEA), a high- and low-molecular-weight keratin, vimentin, epithelial membrane antigen, human milk fat globule, Leu-M1, TAG-72 (identified by monoclonal antibody B72.3), beta 1 pregnancy-specific glycoprotein (SP1), human placental lactogen, secretory component (SC), CA19-9, and S-100 protein were used. Twenty-one adenocarcinomas (91.3%) reacted for CEA, 14 (60.9%) for Leu-M1, 14 (60.9%) for SC, nine (39.1%) for CA19-9, and eight (34.8%) for SP1; no mesotheliomas stained for any of these markers. Nineteen adenocarcinomas (82.6%) and one mesothelioma (5.3%) reacted with B72.3. Adenocarcinomas and mesotheliomas did not significantly vary in reaction to the remaining antibodies. None of the antibodies used was specific for mesothelioma, but CEA was the single most useful marker. One of the two adenocarcinomas negative for CEA was positive for TAG-72, Leu-M1, and SC, and the only B72.3-positive mesothelioma was negative for CEA, Leu-M1, SC, CA19-9, and SP1. These findings indicate that greater sensitivity in differentiating mesothelioma and adenocarcinoma can be achieved by immunostaining for both CEA and one or more of the markers TAG-72 (B72.3), Leu-M1, SC (these three have the highest sensitivity and specificity after CEA), CA19-9, and SP1.

Immunohistochemical analysis of normal and mutated ras oncogene p21 expression in human pulmonary and pleural neoplasms.

In this study we examined 214 cases of primary human pulmonary neoplasms for the expression of a mutated form of the ras oncogene p21 product, recognized by the monoclonal antibody (MCA) DWP. Adjacent serial sections from these same cases had previously been used to demonstrate the frequency of ras p21 expression using the broadly reactive anti-ras p21 MCA RAP-5. Confirmation of the increased expression of p21 was accomplished using MCA Y13-259. The use of adjacent tissue sections from these cases allows the direct comparison of the expression of the mutated and non-mutated forms of ras p21. If reactivity with DWP would prove to be significantly more restrictive than that of the "pan" ras MCAs, RAP-5 and Y13-259, it would lend support to the possibility that DWP (and similar MCAs which detect other specific mutations) could be used to define subsets of these neoplasms based on their specific ras p21 phenotype. Since one would anticipate that the valine/cysteine substitution at position 12 of the ras p21 would occur at only low frequencies in human tumors, our results with DWP are consistent with this hypothesis. As previously reported, RAP-5 reacted with a high proportion of lung tumors (100/214 or 47%). In this report, we demonstrate the selective expression of the mutation recognized by the MCA DWP in only 5% of these same tumors (13/214), and that the expression of this mutated form is not restricted to any of the conventional histological subclasses of pulmonary neoplasms.

Non-occupational malignant mesotheliomas.

The mineral content of the lungs from 84 cases of malignant pleural mesothelioma was estimated by electron microscopy and energy-dispersive X-ray analysis. These cases were chosen because the history of asbestos exposure was absent, indirect or ill-defined. The occupational exposures were classified according to the method of Zielhuis, and the results indicated that this classification is unnecessarily complicated. The chrysotile counts in the lungs from these mesothelioma cases were similar to those in controls and in a previous series of mesotheliomas in which the majority had had direct exposure to asbestos. Amphibole counts were intermediate between those in controls and in the previous series of mesotheliomas with direct asbestos exposure. These findings confirm those of previous studies indicating that amphiboles are more important than chrysotile in the causation of malignant mesothelioma. The results confirm that some mesotheliomas develop in the absence of asbestos exposure.

Asbestos fibre content of lungs with mesotheliomas in Osaka, Japan: a preliminary report.

That crocidolite and amosite are both associated with the development of mesothelioma is now well established, but earlier studies have failed to find an excess of chrysotile in lungs with mesotheliomas as compared with the amounts in lungs of unaffected controls. In an attempt to clarify the importance of fibre type in tissue, an examination of a series of mesotheliomas is being undertaken in Osaka, Japan. A total of 23 mesotheliomas and 5 rejected cases reviewed by the Osaka Mesothelioma Panel were examined for the types of asbestos and semiquantitative fibre content by means of a transmission electron microscope equipped with energy-dispersive X-ray analyser. Asbestos fibres were detected in 19 of the 23 mesotheliomas (21 pleura, 1 pericardium, 1 peritoneum; 19 males, 4 females). Amphibole fibres were found in 13 cases. Five pleural and one peritoneal mesothelioma were found to have only chrysotile fibres. One female pleural mesothelioma with neighbourhood exposure had short chrysotile fibres. Among the 5 rejected cases, only one case with occupational exposure had both chrysotile and amosite fibres. A group of 17 controls were also examined and asbestos fibres were found in 5. Our data, while not definitive, suggest that mesotheliomas can be induced in humans, not only by crocidolite and amosite, but also by chrysotile, though possibly to a lesser extent.

Correlation between lung fibre content and disease in East London asbestos factory workers.

The lungs from 36 former workers at an East London asbestos factory dying of asbestos-related disease were compared with lung tissue from 56 matched control patients operated on in East London for carcinoma of the lung. The severity of asbestosis and the presence of pulmonary carcinoma or mesothelioma of the pleura or peritoneum were correlated with an asbestos exposure index and with the type and amount of mineral fibre of the lungs. Asbestosis was associated with far heavier fibre burdens than mesothelioma. Moderate or severe asbestosis was more common among those with carcinoma of the lung than in those with mesothelial tumours. Crocidolite and amosite asbestos were strongly associated with asbestosis, carcinoma of the lung and mesothelial tumours, whereas no such correlation was evident with chrysotile or mullite. It is suggested that greater emphasis should be placed on the biological differences between amphibole and serpentine asbestos fibre.

Localized benign biphasic mesothelioma of the pleura.

A localized benign biphasic mesothelioma of the pleura is described. Immunohistochemically the epithelial-like cells contained vimentin intermediate filaments only, while electron microscopy revealed signs of true mesothelial differentiation demonstrating the hybrid nature of neoplastic mesothelial cells.

Diagnostic interest of the monoclonal antibody CA1 in malignant pleural effusion.

The Ca1 antibody was used in an immunohistochemical procedure on smears of cells from 40 patients with malignant pleural effusion. The control group consisted of 25 benign pleural effusions with a high percentage of reactive mesothelial cells. The Ca1 Mc Ab was positive in 19 (79%) of the 24 pleural effusions with positive malignant cytology. In all the benign cases the Ca1 Mc Ab was negative (100% specificity). The Ca1 Mc Ab detected malignant mesothelial cells in two cases and was negative with reactive mesothelial cells and other nucleated cells present in the pleural effusion. We conclude that the Ca1 antibody offers a useful diagnostic method for malignant pleural effusions, when the morphological interpretation is doubtful.

Placental protein 10: levels in benign and malignant ovarian cyst fluids and pleural exudates.

Placental protein 10 (PP10) was measured in benign (n = 47) and malignant (n = 10) ovarian cyst fluids and in pleural fluid specimens from 19 patients with pleural metastases of various carcinomas (n = 15) or infectious pleurisy (n = 4). PP10 was found in 9 out of 18 follicular or luteal cyst fluids (range 2.0-42.0 micrograms/l) and in 24 out of 29 benign ovarian tumours (range 2.6-38.0 micrograms/l). Nine out of ten malignant ovarian cyst fluids contained detectable PP10 (range 4.0-55.2 micrograms/l). PP10 was found in all the pleural fluids from 15 patients with metastatic bronchial, pulmonary, breast or pancreatic carcinomas (range 5.1-100.2 micrograms/l), as well as from four patients with pleurisy (range 5.0-28.6 micrograms/l). Our results indicate that PP10 is tumour-associated, but not tumour-specific.

Immunohistochemical evaluation of ras oncogene expression in pulmonary and pleural neoplasms.

We undertook an immunohistochemical analysis of human bronchopulmonary epithelial neoplasms and pleural mesotheliomas using a monoclonal antibody which recognizes ras oncogene products (p21ras). The monoclonal antibody, RAP-5, recognizes both unaltered and certain mutated p21ras. Formalin fixed and paraffin embedded tissue samples of 187 lung epithelial tumors and 27 pleural mesotheliomas were investigated; normal and bronchiectatic lungs were similarly studied. Normal lung and pleural tissue did not immunostain except for occasional type II pneumocytes. Reactive type II pneumocytes adjacent to carcinomas and bronchiectasis immunostained consistently. Twenty four/34 (71%) squamous carcinomas immunostained. Only 8/50 (16%) adenocarcinomas immunostained focally and weakly whereas 19/24 (79%) bronchioloalveolar carcinomas immunostained. Eleven/18 (61%) large cell carcinomas immunostained with variable intensity. Eleven/13 (85%) carcinoids, 6/7 (85%) well differentiated neuroendocrine carcinomas, and 18/21 (86%) intermediate cell neuroendocrine carcinomas immunostained while none of 20 small cell neuroendocrine carcinomas immunostained. Only a few mesotheliomas were immunostained focally. Two/14 (14%) epithelial type and 1/9 (11%) biphasic type mesotheliomas immunostained weakly; none of 4 spindle cell mesotheliomas immunostained. We conclude that while at least occasional cases of most types of pulmonary epithelial neoplasms express p21ras, the frequency and intensity of the expression are distinctly greater in certain tumor types such as squamous, bronchioloalveolar, and neuroendocrine neoplasm except for the small cell type. Contrary to these lung epithelial neoplasms, most mesotheliomas did not immunostain for p21ras. Whether the enhanced p21ras expression may point to a different mechanism of transformation or may merely reflect differentiation features remains undetermined.

Estrogen and progesterone receptors in neoplastic cells of metastatic pleural effusion of breast carcinoma before and after tamoxifen therapy. Correlation with the clinical response.

We have investigated the activity of tamoxifen in 12 post-menopause patients affected by advanced breast carcinoma and, in this specific case, by metastatic pleural effusion. A receptor assay was carried out on all patients to assess the estrogen and progesterone receptor activity in pleural effusion tumor cells, cytologically confirmed. The assay was performed both at the moment of the diagnostic check and after a week of 30 mg/die of tamoxifen therapy. We obtained a temporary reduction of the pleural effusion in 5 patients out of 12 (42%). Four out of these 5 patients presented estrogen receptors (ER+) at the first assay. In the 4 patients with negative receptors (ER-) neither a decrease of the percentage of tumoral cells, nor a reduction of the effusion was ascertained. This study shows that also for pleural effusions tamoxifen's therapeutic benefit was obtainable only in those patients with estrogen receptors in the tumoral cells.