1/48. Beta-HCG aberrant expression in primary mediastinal large B-cell lymphoma.We report on a primary mediastinal large B-cell lymphoma with aberrant expression of beta-human chorionic gonadotropin (beta-hCG). The patient, a 33-year-old man, had cough, dyspnea, fever, superior vena cava syndrome, and a mediastinal bulky tumor. A biopsy showed that the latter was characterized by large cells, sclerosis, and compartmentalization. The neoplastic elements expressed CD45, CD20, CD79a and, partially, CD30, whereas they were negative for CD3, epithelial membrane antigen and cytokeratins. Surprisingly, they displayed a clear-cut positivity for beta-hCG. The remaining oncofetal markers applied (PLAP and alpha1-fetoprotein) were negative. Electron microscopy demonstrated the presence of numerous nuclear pockets and the lack of intercellular junctions. dna analysis by polymerase chain reaction showed clonal rearrangement of Ig heavy-chain genes. The patient responded promptly to the administration of MACOP-B. To the best of our knowledge, this is the first example of B-cell lymphoma showing positivity for beta-hCG; a similar aberrant expression was previously observed only in three Japanese patients with human T-cell lymphotropic virus type I adult T-cell lymphoma/leukemia. Because primary mediastinal large B-cell lymphoma has in the past been frequently confused with germ cell tumors, pathologists should be aware of possible beta-hCG expression by lymphomatous cells to avoid the risk of misdiagnosis.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/48. An autopsy case of a malignant pericardial mesothelioma in a Japanese young man.An autopsy case of a malignant pericardial mesothelioma in a 27-year-old man with no history of exposure to asbestos is reported. He was admitted for heart failure due to pericardial effusion of unknown origin and surgically drained, but later died. The diagnosis of a malignant pericardial mesothelioma was made on the basis of histologic, immunohistochemical and ultrastructural findings. The tumor was located on the pericardium, but autopsy revealed that it had spread extensively in the mediastinum and the lungs. Microscopically, the tumor cells were epithelial like and contained histochemically demonstrable glycogen and hyaluronic acid. Immunohistochemical studies of the tumor demonstrated positive immunoreactivity for cytokeratin 19, muscle actin HHF35, epithelial membrane antigen, CA125, p53 and p21WAF1/CIP1 whereas the tumor was negative for cytokeratins 10 and 17, carcinoembryonic antigen, vimentin, epithelial antigen BerEP4, S-100, c-erbB2 and bcl-2. A high MIB-1 labeling index was noted. Under the electron microscope the tumor cells exhibited long, thin villi. The operation and autopsy findings thus revealed this to be a very rare case of malignant pericardial mesothelioma in a young man.- - - - - - - - - - ranking = 3keywords = antigen (Clic here for more details about this article) |
3/48. Neuroendocrine carcinoma of the posterior mediastinum: a possible primary lesion.A paravertebral mass was noted in the posterior mediastinum in a 47-year-old man. Microscopically, the tumor showed solid and trabecular patterns and consisted of poorly differentiated atypical cells that often formed Flexner-Wintersteiner rosettelike glands. Immunohistochemically, the tumor cells expressed both epithelial and neuroendocrine markers, including cytokeratin (AE1/3), carcinoembryonic antigen, epithelial membrane antigen, neuron-specific enolase, chromogranin a, and synaptophysin, but were negative for CD99 (MIC2). Ultrastructurally, numerous desmosomes and neurosecretory granules were identified in the tumor cells. The present lesion was a primary neuroendocrine carcinoma of the posterior mediastinum-an unusual site for such a lesion.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
4/48. Benign mediastinal teratoma complicated by cardiac tamponade: report of a case.We present herein the case of a 48-year-old woman with a benign mediastinal teratoma that had been followed up for 3 years, who developed acute cardiac tamponade. The patient had initially undergone an exploratory sternotomy, at which time the tumor was histologically diagnosed as a benign mature teratoma that could not be resected due to its severe, wide adhesion to the surrounding organs. However, following the development of cardiac tamponade, both sternotomy and right intercostal thoracotomy were employed, and the tumor could be excised with cardiopulmonary bypass standby. High levels of amylase and carbohydrate antigen 19-9 were revealed in the pericardiac effusion fluid. The mRNA expression of inflammatory cytokines including interleukin-1 (IL-1), IL-6, and IL-8 in the tumor tissue was also demonstrated by a reverse transcriptase-polymerase chain reaction analysis. This case illustrates the ultimate natural course of benign mediastinal teratoma and emphasizes the importance of early surgical excision, even when this tumor is asymptomatic.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
5/48. Extramedullary manifestation of multiple myeloma (systemic plasmacytoma) that simulates hemangioma.We describe 2 cases of a unique type of extramedullary manifestation of multiple myeloma (systemic plasmacytoma) that presented as subcutaneous nodules and mediastinal mass, respectively. Both lesions had a similar morphologic appearance, with dilated vascular-like lumina that was separated by thin fibrovascular septa, filled with erythrocytes, and lined by mature and immature plasma cells and plasmacytoid cells. The plasma and plasmacytoid lining cells showed kappa light chain restriction in both cases, consistent with a B-cell monoclonal process. The lining cells were also focally positive for epithelial membrane antigen but were negative for endothelial cell markers. Abundant delicate capillaries were seen in the septa that separated the vascular lumina, mimicking a vascular tumor. Furthermore, we believe that our cases are different from the previously described blood lakes in a plasmacytoma by the presence of well-formed fibrovascular septa that separated the vascular-like spaces. Neoangiogenesis propagated by myeloma cells may contribute to this unusual morphologic manifestation of extramedullary manifestation of multiple myeloma.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
6/48. autoimmunity to gephyrin in Stiff-Man syndrome.Stiff-Man syndrome (SMS) is a rare disease of the central nervous system (CNS) characterized by chronic rigidity, spasms, and autoimmunity directed against synaptic antigens, most often the GABA-synthesizing enzyme glutamic acid decarboxylase (GAD). In a subset of cases, SMS has an autoimmune paraneoplastic origin. We report here the identification of high-titer autoantibodies directed against gephyrin in a patient with clinical features of SMS and mediastinal cancer. Gephyrin is a cytosolic protein selectively concentrated at the postsynaptic membrane of inhibitory synapses, where it is associated with GABA(A) and glycine receptors. Our findings provide new evidence for a close link between autoimmunity directed against components of inhibitory synapses and neurological conditions characterized by chronic rigidity and spasms.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
7/48. Small-cell variant of synovial sarcoma: fine-needle aspiration with ancillary features and potential diagnostic pitfalls.We report a small-cell variant of synovial sarcoma examined by fine-needle aspiration (FNA) biopsy. The patient is a 23-yr-old female who had a synovial sarcoma involving the left infratemporal region, diagnosed at 7 yr of age, followed by a metastatic lesion involving the lung and chest wall 16 yr later. The chest wall metastases was sampled by FNA biopsy. The aspirate consisted of numerous, small, round cells with very high nuclear-to-cytoplasmic ratios. The cytomorphologic features could potentially be confused with other pediatric small round cell tumors. Ancillary studies demonstrated positive staining of the neoplastic cells for cytokeratin, epithelial membrane antigen (EMA), and CD99. The differential diagnosis of other small round cell tumors that may be mistaken for the small-cell variant of synovial sarcoma are presented. We believe that this is the first FNA report detailing the cytologic and ancillary features of the small-cell variant of synovial sarcoma.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
8/48. Blastic natural killer cell lymphoma arising from the mediastinum with terminal deoxynucleotidyl transferase expression.Blastic natural killer (NK) cell lymphoma/leukemia is a relatively rare NK cell malignancy. We report the second case of blastic NK cell lymphoma arising from the mediastinum with an aggressive clinical course. The patient was a 63-year-old Japanese man with an anterior mediastinum tumor. The biopsy specimen showed diffuse proliferation of tumor cells with frequent mitotic figures and apoptotic bodies. Both angiocentric features and small foci of coagulative necrosis were found in this section. The tumor cells had medium to large nuclei with a fine chromatin pattern, inconspicuous nucleoli and scanty cytoplasm. The nuclear contour was oval to moderately irregular, showing slight pleomorphism as compared with typical lymphoblastic lymphoma. The tumor cells were positive for CD2, CD56 and terminal deoxynucleotidyl transferase, but negative for other T-cell antigens, B-cell antigens and myeloid markers. in situ hybridization for Epstein-Barr virus encoded small ribonucleic acid 1 was negative.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
9/48. Spontaneous rupture of mediastinal cystic teratoma into the pleural cavity: report of two cases and review of the literature.The authors report on two female patients aged 12 and 14 years, who spontaneously developed a rupture of benign mediastinal cystic teratoma into the right pleural cavity. They presented with acute onset of severe chest pain and respiratory distress. The tumors were completely resected by thoracotomy. The serum and pleural fluid levels of carcinoembryonic antigens, CA-125 and CA19-9 were invariably elevated, then decreased to normal range after the surgical resection. Rapid diagnosis of this extremely rare complication is important because it may progress to a life-threatening condition.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
10/48. Anaplastic large cell lymphoma of the mediastinum diagnosed by transbronchial scratch cytology. A case report.BACKGROUND: Anaplastic large cell lymphoma (ALCL) is a subtype of non-Hodgkin's lymphoma characterized by CD30 antigen-positive, large neoplastic cells. We describe a case of ALCL suggested by cytologic examination of the tumor cells obtained from bronchial scratch preparations. CASE: A 26-year-old woman had had a dry cough since November 1996. Chest radiography in May 1997 revealed an abnormal shadow in the mediastinum extending to the pulmonary hilar region. The patient was hospitalized in June 1997. Computed tomography revealed a neoplastic lesion in the anterior mediastinum invading the right lung. Transbronchial scratch cytology revealed large, atypical lymphoid cells expressing CD30 and CD3 on immunocytochemical examination. A transcutaneous mediastinal biopsy was performed and a diagnosis of ALCL made. CONCLUSION: Differentiation from Hodgkin's disease was the most difficult point in this case. Detailed cytologic observation and CD3-positive immunocytology led to the correct diagnosis. The cell transfer technique of Sherman et al was very useful for immunocytologic staining. Thus, transbronchial scratch cytology was an especially valuable and effective procedure in this case.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
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