The MAL gene is expressed in primary mediastinal large B-cell lymphoma.
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Primary mediastinal large B-cell lymphoma (PMBL) appears to be a distinct clinicopathologic entity among diffuse large B-cell lymphomas (DLBLs). To find molecular alterations associated with this disease, we compared the mRNAs expressed in 3 PMBLs and 3 peripheral DLBLs by differential display-reverse transcription (DDRT) and identified a mRNA specifically expressed in PMBLs. Sequence analysis showed that this mRNA is encoded by the MAL gene, the expression of which was shown to be restricted to the T-cell lineage during hematopoiesis. MAL gene expression was demonstrated by Northern blot and reverse transcription-polymerase chain reaction (RT-PCR) in 8 of 12 PMBLs. However, there was little or no MAL gene expression in 8 peripheral DLBLs. Immunohistochemical analysis evidenced expression of MAL protein in tumoral B cells restricted to the PMBL subtype. Finally, Southern blot studies did not demonstrate rearrangement of the MAL gene. Altogether, our results indicate that MAL expression is recurrent in PMBLs, providing further evidence that PMBL represents a distinct entity among DLBLs. Because MAL protein is located in detergent-insoluble glycolipid-enriched membrane (GEM) domains involved in lymphocyte signal transduction, abnormal expression of MAL protein in the B-lymphoid lineage may have significant implications in PMBL lymphomagenesis. (+info)
CNS involvement in primary mediastinal large B-cell lymphoma.
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PURPOSE: The risk of CNS involvement by non-Hodgkin's Lymphoma (NHL) has been associated with bone marrow and/or testicular involvement; however, it was recently reported that the number of extranodal sites is a more reliable predictor of CNS disease. Because primary mediastinal thymic large B-cell lymphoma (PMLCL) has a high propensity for involving extranodal sites, we investigated the frequency and pattern of CNS involvement in PMLCL. PATIENTS AND METHODS: The medical records of 219 patients with aggressive NHL, consecutively entered onto protocols at the National Cancer Institute between 1987 and 1998, were retrospectively reviewed. RESULTS: Twenty-three patients (11%) had clinical and pathologic features of PMLCL. These patients were young (median age, 29 years), female (61%), and presented with massive mediastinal adenopathy (70%). Extranodal disease occurred at presentation in 70% and at relapse in 93% of patients and involved contiguous intrathoracic structures and/or distant sites, including the lungs, kidneys, liver, adrenals, ovaries, pancreas, and bone. Six patients (26%) developed CNS involvement, two (9%) at presentation and four (27%) at relapse. All had extranodal disease, but only one had bone marrow involvement. Parenchymal and leptomeningeal CNS disease occurred in four and three patients, respectively. CONCLUSION: CNS involvement in PMLCL is associated with extranodal involvement other than bone marrow and may reflect the unique biology of this disease. The propensity to involve the CNS parenchyma raises the concern that intrathecal prophylaxis may not be effective and suggests that CNS imaging should be considered in patients with extranodal disease. (+info)
Non-Hodgkin's lymphoma in children: results of treatment with LSA2-L2 protocol.
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The results obtained with very intensive treatment in previously untreated patients early in the disease are encouraging, and we hope will change the philosophy of most investigators that even in far advanced disease such as those with marrow metastases or multiple primary sites, one can still obtain complete regression at all tumour sites within 1 to 1 1/2 months from onset of therapy by combined treatment with multiple chemotherapeutic agents and radiation therapy to one or more sites. (+info)
BACKGROUND: The association between primary germ cell tumors of the mediastinum (the space between the lung pleura that contains the heart and other chest viscera) and hematologic malignancies has been described by retrospective analysis of patients treated at individual clinical centers. To better characterize the risk of hematologic disorders in patients with extragonadal germ cell tumors and to describe the clinical and biologic features of the disorders, we studied an unselected population in a large, international, multicenter database. METHODS: Six hundred thirty-five patients treated at 11 centers in the United States and Europe from 1975 through 1996 were evaluated retrospectively. RESULTS: A hematologic disorder was observed in 17 patients with germ cell tumors. All cases developed among the 287 patients with primary mediastinal nonseminomatous germ cell tumors, giving an incidence rate in this group of 2.0% (95% confidence interval [CI] = 1.1%-3.1%) per year over a median follow-up time of 3 years. The risk of developing hematologic disorders was statistically significantly increased in patients with primary mediastinal nonseminomatous germ cell tumors in comparison with the age-matched general population (standardized incidence ratio = 250; 95% CI = 140-405). The median time to onset of hematologic neoplasia was 6 months (range, 0-47 months), and the median survival after diagnosis of the hematologic disorder was 5 months (range, 0-16 months) (two-sided P<.0001, comparing survival from the time of diagnosis of the germ cell tumor of patients with and without hematologic disorders). CONCLUSION: In our study, approximately one in 17 patients with primary mediastinal nonseminomatous germ cell tumors was affected by a hematologic disorder, whereas no cases were seen among 334 patients with other extragonadal germ cell tumors. The hematologic disorder had a statistically significant impact on prognosis, with none of the 17 reported patients surviving for more than 2 years. (+info)
Cyclophosphamide and carboplatin and selective consolidation in advanced seminoma.
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This prospective Phase II study assesses the clinical efficacy and complications of a treatment regimen of combination chemotherapy with cyclophosphamide and carboplatin and selective consolidation in advanced seminoma. Of 46 patients who entered the study between December 1992 and October 1998, 46 were evaluable. Thirty-two achieved a complete remission (70%; 95% confidence interval, 56-83%) after chemotherapy alone. Fourteen achieved a complete remission (30%; 95% confidence interval, 18-46%) after chemotherapy plus consolidation. Forty-three of the 46 patients (93%; 95% confidence interval, 82-97%) remained in remission after a median follow-up period of 27.4 months. No patient experienced nephrotoxic, neurotoxic, or ototoxic effects or hemorrhagic cystitis. No patient had neutropenic fever requiring hospitalization. Thirteen % required platelet transfusions, and 9% required transfusions of packed RBCs. For patients with advanced seminoma, treatment with cyclophosphamide and carboplatin and selective consolidation is safe and effective. (+info)
Primary mediastinal germ cell tumors in children and adolescents: results of the German cooperative protocols MAKEI 83/86, 89, and 96.
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PURPOSE: To evaluate children and adolescents with primary mediastinal teratoma and malignant germ cell tumors (GCTs). PATIENTS AND METHODS: Forty-seven patients from the German nontesticular GCT studies were analyzed (median age, 2.5 years; range, neonate to 17 years). Teratoma (n = 21) were resected, and no adjuvant treatment was given. Malignant GCTs (n = 26) were treated with cisplatin-based chemotherapy and resection. Three of 26 patients underwent radiotherapy. RESULTS: In all patients with teratoma, tumor markers were normal. Surgery of teratoma was complete in 17 of 21 patients and microscopically incomplete in four of 21 patients, and we observed no relapse after a median follow-up of 29 months. In 23 of 26 patients with malignant GCTs, alpha-fetoprotein and/or beta-human chorionic gonadotropin were elevated. Twelve of 26 patients received adjuvant chemotherapy after initial resection, which was complete in six of 12 patients, whereas delayed resection after preoperative chemotherapy was complete in 10 of 11 patients (P =.03). Four of six patients underwent second-look thoracotomy after incomplete primary surgery. Three of 26 patients did not undergo tumor resection. The final completeness of resection was the strongest prognostic indicator (event-free survival inverted question markEFS, 0.94 +/- 0.06 v 0.42 +/- 0.33; P <.002). Local stage and distant metastases were not prognostically significant at the.05 level. For all malignant GCTs, the 5-year survival rate was 0.87 +/- 0.05 (median follow-up, 51 months), with an EFS of 0.83 +/- 0.05. CONCLUSION: The prognosis of mediastinal teratoma is excellent after complete or microscopically incomplete resection. In children with malignant GCT, the prognosis is favorable with a therapeutic strategy of delayed resection after preoperative chemotherapy. In most children, the diagnosis can be based on elevated tumor markers and imaging. Biopsy is indicated in nonsecreting GCT. (+info)
Thymic neuroendocrine carcinomas with combined features ranging from well-differentiated (carcinoid) to small cell carcinoma. A clinicopathologic and immunohistochemical study of 11 cases.
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We reviewed 11 cases of primary thymic neuroendocrine carcinomas with combined features ranging from well-differentiated to poorly differentiated neuroendocrine carcinoma. For 3 asymptomatic patients, tumors were discovered during routine examination. Presentation in the other patients was as follows: Cushing syndrome, 2 patients; chest pain, 3 patients; superior vena cava syndrome, 1 patient; and hypercalcemia and hypophosphatemia, 1 patient. No clinical data were available for the 11th patient. All tumors were located in the anterior mediastinum and treated by surgical excision. The lesions were large and well-circumscribed with areas of hemorrhage and necrosis. They were characterized by areas showing a proliferation of monotonous, round tumor cells adopting a prominent organoid pattern admixed with areas showing sheets of atypical cells with hyperchromatic nuclei, frequent mitoses, and extensive areas of hemorrhage and necrosis. Immunohistochemical studies performed in 6 cases showed strong CAM 5.2 low-molecular-weight cytokeratin positivity in all cases, chromogranin and synaptophysin positivity in 4, Leu-7 in 3, and focal positivity for p53 in 2. Follow-up information for 9 cases showed that all patients died of their tumors between 1 and 4 years after diagnosis. The present cases highlight the heterogeneity of neuroendocrine neoplasms and reinforce the notion that these tumors form part of a continuous spectrum of differentiation. (+info)
Incidence rates of malignant mesothelioma in Denmark and predicted future number of cases among men.
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OBJECTIVES: This study analyzed the incidence rates of malignant mesothelioma in Denmark in order to predict the future number of cases that will occur among Danish men. METHODS: The 1912 cases of malignant mesothelioma reported to the Danish Cancer registry in 1943-1993 were analyzed in order to describe current incidence rates. By a Poisson regression model the relative risks of synthetic birth cohorts were estimated and used in the prediction of the future number of cases that will occur among Danish men. RESULTS: The incidence rate increased to 1.33 per 100000 person-years in 1983-1987 among men and to 0.51 in 1973-1977 among women. From the Poisson regression model, the risk for birth cohorts of men, relative to the 1940-1944 cohort, peaked in the 1940-1944 cohort and decreased to 0.57 in the 1950-1954 cohort. The age-specific incidence rate peaked at 246 per 100000 person-years in the age group 80-84 years. The future annual number of mesothelioma cases is expected to peak around 2015 with 93 cases among men born before 1955. CONCLUSIONS: The fit of the models was not ideal, but with careful interpretation of the results, it was concluded that a further increase in the number of mesothelioma cases can be expected, and the effect of regulating the environmental exposure to asbestos cannot be expected within the next 10-15 years. (+info)