1/21. Localized malignant mesothelioma of the pleura.We describe a case of malignant pleural mesothelioma appearing as a solitary pleural tumor in a 56-year-old Japanese man with no history of exposure to asbestos. A chest radiograph revealed an isolated extrapulmonary mass in the left hemithorax. The patient underwent tumor resection, but the tumor later recurred on the contralateral pleura. The patient developed cerebral metastases and died 16 months after the initial surgery. The resected tumor was sessile with broad-based pleural attachment. Microscopically, the tumor was composed of interlacing fascicles of plump spindle cells intermixed with few polygonal cells. Most of the tumor cells showed positive immunoreactivity for cytokeratins (AE1 and AE3) and vimentin. Many of the tumor cells were positive for epithelial membrane antigen, and a few were positive for desmin. In contrast, the tumor cells were consistently negative for carcinoembryonic antigen, epithelial antigen BerEP4, calretinin, S-100 protein, neuron-specific enolase, muscle actin antigen HHF35, alpha-smooth muscle actin antigen and CD34. Ultrastructurally, the tumor cells had diffusely distributed cytoplasmic intermediate filaments, desmosome-like junctions, and a few microvilli. Some tumor cells contained cytoplasmic tonofilaments. Immunohistochemical and ultrastructural findings supported the mesothelial nature of the tumor, and led us to diagnose this tumor as a sarcomatoid localized malignant mesothelioma.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
2/21. P53 gene mutations in pleuropulmonary blastomas.Pleuropulmonary blastoma (PPB) is rare childhood tumor oniginating from either lung or pleura. Although several cytogenetic changes, such as tisomy 2, trisomy 8, and loss of 17p material, have been reported, evidence of gene mutations is still lacking. Pathologically, PPB shares similarities with rhabdomyosarcoma in which p53 mutations arefrequently detected. Possible implication of p53 mutations in PPB was investigated. PPBs of 3 patients were analyzed for occurrence of p53 mutations by using polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) method, and the nature of mutations was confirmed by direct sequencing. Two PPBs were confirmed to harbor p53 mutations. One was a Val to Leu substitution at codon 173, and another was a ArgArg to TrpCys substitution at codons 282 and 283. In each tumor, only the mutated allele was detected, suggesting inactivation of p53. Both patients with mutations had fatal outcome, while the remaining patient in whom no mutation was detected is disease free for 3 years after completion of treatment. The results raise the possibility that p53 inactivation can occur as a nonrandom genetic change involving the pathogenesis and outcome of PPB. Further studies in a larger series are necessary to clarify these matters.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
3/21. Malignant mesothelioma: PAS-diastase positivity and inversion of polarity in intravascular tumour.AIMS: periodic acid-Schiff (PAS)-diastase-positive material was identified within pseudoglandular structures within the small intravascular component of two pleural malignant mesotheliomas. The aim of this study was to ascertain the nature of this material and to asses the polarity of the cells forming the pseudoglandular structure. methods AND RESULTS: immunohistochemistry was performed using antibodies to laminin and type IV collagen and the antibody HBME-1. These demonstrated the material to be basement membrane rather than mucin. The apical polarity marker HBME-1 was not related to the internal pseudoglandular structure but stained the periphery of intravascular tumour clumps. CONCLUSIONS: Pseudoluminal PAS-diastase-positive material in malignant mesothelioma may easily be mistaken for epithelial mucin, leading to an erroneous diagnosis of adenocarcinoma. The presence of basement membrane material in pseudolumina, as defined by the presence of laminin and type IV collagen, surrounded by tumour cells whose external surface expresses the apical polarity marker HBME-1 implies inversion of polarity of tumour cells within vascular spaces.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
4/21. Malignant pleural mesothelioma: a case report.OBJECTIVE: The aim of this study was to discuss a case of malignant pleural mesothelioma (MPM) that presented to a chiropractic teaching clinic and review the pathophysiology of diseases associated with asbestos exposure. CLINICAL FEATURES: An 86-year-old woman had right-sided back pain at the thoracolumbar junction for 3 months; this pain prevented her from exercising on a daily basis. She was alert and oriented but in obvious distress because of her back pain. Breath sounds were decreased on the right in the posterior and lower lobes, with dull percussion and increased tactile fremitus. A significant collection of pleural effusion was seen on the right side on plain film radiographs. A chest computed tomography with contrast showed a large right-sided pleural effusion with small consolidation at the right lung base suggestive of pleural or pulmonary malignancy and highly suspicious for MPM. Further questioning about asbestos exposure revealed that her husband was a maintenance worker. An extrapleural pneumonectomy was performed, and specimens of parietal and visceral pleura were sent for pathological, which revealed a definitive diagnosis of spindle cell mesothelioma. INTERVENTION AND OUTCOME: The patient was diagnosed with MPM, and a surgical therapy option was considered because of the aggressive nature of the lesion and her advanced age. An extrapleural pneumonectomy was performed with removal of parietal and visceral pleura, right lower lobe, and right hemidiaphragm. CONCLUSION: This is an unusual case of advanced MPM that is most likely from indirect asbestos exposure.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
5/21. Extracranial metastases of glioblastoma multiforme confirmed by electron microscopy.A case of glioblastoma multiforme which metastasized to the pleura and the lymph nodes of the neck is described. The metastases were detected during the life of the patient. The glial nature of the metastases was confirmed by electronmicriscopic demonstration of typical 90-100 angstrom wide glial fibrils occupying the tumor cell cytoplasm. Electronmicroscopy is recommended to prove the astrocytic nature of a metastatic glioblastoma multiforme. A review of the literature of histologically documented extracranial metastases of glioblastoma multiforme reveals an increase in frequency in recent years. Increased efforts at detection and documentation or an increase in occurrence caused by new methods of treatment are the two possible explanations for this trend.- - - - - - - - - - ranking = 2keywords = nature (Clic here for more details about this article) |
6/21. Inflammatory fibrous histiocytoma (? anthogranuloma). Report of two cases with ultrastructural observations in one.Two cases of inflammatory fibrous histiocytoma are presented, one occupying the pleural space, and the other the retroperitoneum. One of the cases was studied with the electron microscope and confirmed the histiocytic and xanthomatous nature of the lesion. It is suggested that the term xanthogranuloma be replaced by fibrous histiocytoma, and that when a considerable inflammatory component is present in the stroma, a guarded prognosis be entertained. Ultrastructurally there are no distinctive features for the inflammatory variant of the fibrous histiocytoma.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
7/21. 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.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
8/21. Spontaneous regression of a pleural thickening with the histological appearance of an inflammatory pseudotumour.The inflammatory nature of a tumour-like lesion not formerly observed in the parietal pleura was confirmed histologically using immunohistochemical analysis and clinically by spontaneous regression. A study of the literature revealed that the histological picture of the lesion was consistent with that of the rarely described inflammatory pseudotumour.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
9/21. 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.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
10/21. light chain myeloma with meningeal and pleural involvement.A 76-year-old woman with newly diagnosed lambda light chain myeloma was found to have involvement of the pleura and meninges. Direct immunofluorescence demonstrated the monoclonal nature of plasma cells found in the pleural fluid; morphologically similar cells were found in the cerebrospinal fluid and bone marrow. immunoelectrophoresis revealed lambda light chains in the pleural fluid and cerebrospinal fluid, as well as in the serum and urine. Clinically apparent pleural involvement and meningeal involvement by myeloma are each rare events. This is believed to be the first report of both phenomena occurring simultaneously and the first known case of light chain myeloma involving the cerebrospinal fluid.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
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