Virchows Archiv

Dhaene, Karl; Verhulst, Anja; Van Marck, E.

doi: 10.1007/s004280050387pmid: 10431839

DNA-like sequences of the p53 and pRB-inactivating simian virus 40 large T-antigen (SV40 LTag) have recently been found in mesotheliomas in the United States and several European countries. Nuclear expression of SV40 LTag, possibly in concert with detectable telomerase activity, could be responsible for immortalisation of (pre)malignant clones, as suggested by the mesothelioma-specific latency period. Depending on the antibody used, different results have been observed regarding the subcellular expression of SV40 LTag in mesotheliomas with SV40 LTag-like DNA sequences. In this study, we screened 28 Belgian mesothelioma tumour samples for the presence of SV40 LTag-like DNA and its gene product by polymerase chain reaction amplification, using the SV.for3/SV.rev primer set, and by tyramine-amplified immunohistochemistry, using the pAb419 and the pAb101 SV40 LTag antibodies. Amplicons were found in 13 of the 28 (46%) mesotheliomas. Cytoplasmic, but no nuclear, staining was found in 10 of these 13 cases. Although our study confirms the presence of SV40 LTag-like DNA sequences in Belgian mesotheliomas, we did not detect nuclear expression of the viral oncoprotein, which makes a pathogenic role of SV40 LTag in mesothelioma carcinogenesis questionable.

König, Jens-Ekkehard; Tolnay, Edina; Wiethege, Thorsten; Müller, K.-M.

doi: 10.1007/s004280050388pmid: 10431840

 Angiogenesis is an important part of normal and pathological processes, including tumour growth, metastasis, inflammation and wound healing. VEGF is the best known angiogenic factor, implicated in tumour-associated microvascular hyperpermeability and carcinogenesis. We investigated 103 malignant pleural mesotheliomas, analysing the expression of vascular endothelial growth factor using immunohistochemistry and insitu hybridization. The grade of microvessel density was assessed with the aid of anti-factor-VIII antibodies. An increased expression of VEGF was found in biphasic and epithelioid mesotheliomas, correlating in a statistically significant manner (P<0.042). Insitu hybridization confirmed the specificity of VEGF mRNA expression. There was a robust correlation between VEGF expression and increased microvessel density (P<0.001), and positive mesotheliomas had significantly higher microvessel densities than negative specimens. There was also a significant correlation between microvessel density and histological pattern. As growth pattern tended towards biphasic and sarcomatoid mesotheliomas the density of micovessels decreased (P<0.05).

Polosukhin, V. V.

doi: 10.1007/s004280050389pmid: 10431841

 Examination of 127 biopsy specimens from 45 patients with inflammatory lung diseases showed changes consistent with increased permeability of the capillary endothelial cells as an initial stage in the development of the inflammatory reaction. Associated interstitial oedema, deformation of the interalveolar septa, and structural disorganization of alveolar epithelium cells occur, and local microcirculatory problems result in tissue hypoxia and fibrosis. The ultimate morphological picture is determined largely by the intensity of repair. Laser biostimulation minimizes the inflammation and stabilizes fibroplastic process.

Fehrenbach, H.; Haase, Michael; Kasper, Michael; Koslowski, Roland; Schuh, Dieter; Müller, Martin

doi: 10.1007/s004280050390pmid: 10431842

To investigate the role of vascular endothelial growth factor (VEGF) in fibrogenesis, the distribution patterns of the VEGF receptors Flt1 and Flk1 were studied by immunohistochemistry, double immunofluorescence, and immunoelectron microscopy in normal (n=2) and bleomycin-treated (n=21) adult rats. Lungs were studied at 5, 24, 28, 35, and 42 days after treatment (p.t.). Flt1, Flk1, and VEGF immunoreactivity localised predominantly to the pulmonary epithelium. In control lungs, Flt1 immunoreactivity was present in ciliated bronchial epithelium and type 2 pneumocytes, Flk1 in Clara cells, and VEGF in Clara cells and type 2 pneumocytes. Flk1 localised to mast cells, present in the peribronchovascular and pleural interstitium only. Flt1- and Flk1-mRNAs were observed in Clara cells and type 2 pneumocytes. Bleomycin-induced fibrogenesis was characterised by a decrease in Flk1 immunoreactivity of Clara cells, and an increase in VEGF-immunoreactive myofibroblasts and type 2 pneumocytes by day 5 p.t., followed by a progressive accumulation of Flk1-immunoreactive mast cells by day 24 p.t. in fibrotic lesions containing VEGF-immunoreactive myofibroblasts. After 42 days, fibrotic regions were densely populated by mast cells. Since mast cells are known to be chemotactically attracted by VEGF, we suggest that VEGF/Flk1 represents the molecular link between proliferation of myofibroblasts, accumulation of mast cells, and the burst of fibrosis at sites of initial lesions in bleomycin-induced fibrosis.

Jiang, Zhong; Xu, Minzhen; Savas, Louis; LeClair, Paula; Banner, B. F.

doi: 10.1007/s004280050391pmid: 10431843

 Invariant chain (Ii) is a chaperone molecule that inhibits binding of endogenous antigens to class II molecules. High levels of Ii in cancer cells may prevent tumour antigen expression with class II and render the tumour less immunogenic. To correlate the expression of Ii and class II molecules in colon carcinomas with the density of tumour infiltrating lymphocytes (TILs), surgical specimens from a total of 48 patients with well- (WDAC), moderately (MDAC) and poorly differentiated adenocarcinomas (PDAC), adenoma with high-grade dysplasia (AdHGD) and adenomas were immunostained for Ii and class II antigen (HLA-DR). Aggregates of TILs were graded in H&E-stained sections. Normal colon epithelium was negative for Ii and HLA-DR. Invasive carcinomas showed a linear increase in the expression of Ii in the progression from low- to high-grade tumours, while there was no significant difference in HLA-DR expression across the groups. Invasive carcinomas showed a disproportionate increase in Ii over HLA-DR. Frequency of TILs showed inverse correlation with expression of Ii and tumour grade. This is the first demonstration that expression of Ii increases in the progression from low- to high-grade colon neoplasms and is most marked in the poorly differentiated carcinomas. Ii expression by carcinomas is inversely related to the frequency of TILs. The findings suggest that increased Ii renders the tumour less immunogenic and less likely to stimulate a host immune response.

Lüttges, J.; Mentzel, T.; Hübner, G.; Klöppel, G.

doi: 10.1007/s004280050392pmid: 10431844

Solitary fibrous tumours usually occur in the pleura, but occasionally they appear in extraserosal soft tissues or parenchymatous organs, where their diagnosis often causes problems. This report describes a solitary fibrous tumour (SFT) of the pancreas in a 50-year-old woman treated by left-side pancreatectomy. The tumour showed immunocytochemical reactivity for CD34, CD99 and bcl-2. Because of its favourable prognosis, SFT must be clearly distinguished from leiomyosarcoma, the most frequent nonepithelial tumour of the pancreas. Other mesenchymal tumours that may occur in the pancreas include tumours of the peripheral nerve sheath, fibrous histiocytic tumours and rare vascular tumours.

Davidson, B.; Risberg, Bjørn; Kristensen, Gunnar; Kvalheim, Gunnar; Emilsen, Elisabeth; Bjåmer, Asle; Berner, Aasmund

doi: 10.1007/s004280050393pmid: 10431845

The detection of malignant cells in pleural, peritoneal, and pericardial fluids of cancer patients marks the presence of metastatic disease and is associated with a grave prognosis. We evaluated five epithelial markers for the detection of cancer cells in 94 fresh pleural, peritoneal and pericardial effusions. Eighty-four of the samples were regarded as adequate for analysis after evaluation of cytological smears, including 61 samples from patients known to have gynaecological neoplasms. The other 23 samples were from patients with various non-gynaecological malignancies or tumours of unknown origin. Our control cases were 10 fallopian tubes not affected by any malignancy and 12 malignant mesotheliomas. Cell blocks from all cases were stained for CA-125, BerEP4, carcinoembryonic antigen (CEA), BG8 (Lewis Y blood antigen), and B72.3 (TAG-72). Fifty-one of 84 cases were diagnosed as malignant or suggestive of malignancy in cytological smears and/or cell block sections. However, staining for epithelial markers highlighted the presence of malignant cells in 7 additional cases. When membrane staining was evaluated, the sensitivity of the markers studied in detecting malignant cells was as follows: CA-125: 88%, BerEP4: 78%, CEA: 26%, BG8: 86%, B72.3: 79%. Membrane positivity for CEA, B72.3 and BerEP4 was not detected in reactive mesothelial cells. However, membranous staining in mesothelial cells was evident in 13% and 31% of cases with the use of BG8 and CA-125, respectively. Weak cytoplasmic staining for CEA was observed in mesothelial cells in 2 cases. When Ber-EP4, B72.3, and BG8 staining results in cancer cells were combined, the following sensitivity levels were observed: BG8+B72.3: 91%; BG8+Ber-EP4: 90%; B72.3+Ber-EP4: 93%; BG8+ Ber-EP4+B72.3: 95%. The detection of malignant cells in effusions is facilitated by the use of immunocytochemistry using a wide panel of antibodies. BerEP4 and B72.3 appear to be the best markers when both sensitivity and specificity are considered, followed by BG8, while CEA and CA-125 have a limited role in the detection of metastases from gynaecological tumours owing to the low sensitivity of the former and the low specificity of the latter. Analysis of all staining results should be based on a thorough morphological examination.

Blair, Harry C.; Dong, Sai-Sai; Julian, Bruce A.

doi: 10.1007/s004280050394pmid: 10431846

Mast cells accumulate in hyperparathyroid bone, but the reason is not clear. We compared the distribution of mast cells and related growth factors in normal and hyperparathyroid bone. Mast cell formation was strongly affected by proximity to bone-forming surfaces of hyperparathyroid bone. Hyperparathyroidism greatly increased the production by active, bone-synthesizing osteoblasts of stem cell factor (SCF) but not of IL-3. Osteoblast SCF was distributed to the basolateral cell membranes, and its cDNA sequence (GenBank AF119835) is homologous to the murine membrane-bound SCF. Quiescent osteoblasts did not produce detectable SCF. Synthetic osteoblasts in normal bone were SCF positive, but comprised a much smaller population of cells, in keeping with the slow turnover of normal bone. Major SCF isoforms on immunoblot analysis of osteoblast-fraction proteins from high-turnover bone had Mrs of about 48 and 40 kDa. Similar SCF isoforms were produced by MG63 osteoblast-derived cells and were identified by several anti-SCF antibodies. SCF is expressed in several mesenchymal cell types in a complementary fashion with cells bearing its receptor. SCF potently facilitates differentiation of mast cells, so the increase in paratrabecular mast cells in hyperparathyroid bone is probably driven by osteoblastic SCF. However, since mast cells are not normal components of bone, osteoblastic SCF probably regulates other cells, with mast cell differentiation occurring as a side effect greatly increased osteoblastic activity.

Vlodavsky, E. A.; Ludatscher, Ruth M.; Sabo, Edmond; Kerner, Hedviga

doi: 10.1007/s004280050395pmid: 10431847

 The capillary basement membranes from 16 skeletal muscle biopsies from patients with a clinical and histological diagnosis of inflammatory myopathy and from six controls were analysed ultrastructurally and morphometrically. Resin sections from 244 endomysial capillaries were examined by light microscope, and the results were correlated with findings seen in electron micrographs of these capillaries. The ultrastructural morphometric measurements and the statistical analysis showed that the capillary basement membrane was thick and multilaminated in 87% specimens affected by inflammatory myopathy. No thick or multilaminated basement membrane was observed in controls. In inflammatory myopathy the endomysial space next to the capillaries contained an increased amount of collagen fibrils and showed signs of a chronic reparative process. It is suggested that the thick multilaminated basement membrane in inflammatory myopathy represents an advanced stage of vascular regeneration.

Miracco, C.; Laurini, Lorella; Santopietro, Rosa; De Santi, Maria Margherita; Sassi, Carlo; Neri, Eugenio; Pepi, Fiorella; Luzi, Pietro

doi: 10.1007/s004280050396pmid: 10431848

 We report an intimal sarcoma presenting as an aortic aneurysm. A 68-year-old man suffered from chest pain and speech disturbance. Computed tomography showed a sacciform aneurysm of the aorta, which was resected, revealing a polypoid tumour measuring 1.5×2×2.5 cm projecting into the lumen. This proved to be a poorly differentiated high-grade sarcoma having morphological, immunophenotypic and ultrastructural features consistent with rhabdomyosarcomatous differentiation. Primary sarcomas of the aorta are extremely rare. Many cases have been diagnosed as ”intimal” on the basis of their site of origin, and they are not easy to classify from their histological pattern. Electron microscopy and the use of a more comprehensive panel of immunohistochemical markers should be applied in the histological classification of ”intimal” sarcoma.