RESUMO
We report the case of a 42 year-old woman with myasthenia gravis associated with a malignant thymoma. Despite surgery, chemotherapy and radiotherapy, the thymoma showed soft tissues, pleural and mediastinic progression. Unexpectedly, a complete remission of the thymoma was confirmed by FDG-PET after four cycles of immunoglobulins, administered as treatment for a myasthenic crisis. To our knowledge this is the first case report of complete remission of a malignant thymoma with immunoglobulin therapy.
Assuntos
Imunoglobulinas Intravenosas/uso terapêutico , Fatores Imunológicos/uso terapêutico , Miastenia Gravis/complicações , Miastenia Gravis/tratamento farmacológico , Timoma/tratamento farmacológico , Timoma/etiologia , Neoplasias do Timo/tratamento farmacológico , Neoplasias do Timo/etiologia , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Feminino , Humanos , Indução de Remissão , Neoplasias Torácicas/tratamento farmacológico , Neoplasias Torácicas/secundário , Timoma/secundário , Neoplasias do Timo/patologia , Falha de TratamentoRESUMO
BACKGROUND: It is well documented that over-expression of the c-myc proto-oncogene occurs in the vast majority of mouse thymic lymphomas induced by gamma-irradiation, evidencing the importance of this gene in T-cell lymphomagenesis. However, it remains unknown whether elevated levels of c-myc expression are driven by extra c-myc copy numbers. MATERIALS AND METHODS: Here we use a quantitative test on the basis of real-time PCR to determine the cellular copy number of c-myc in a set of 14 g-radiation- induced thymic lymphomas obtained from (C57BL/6J x BALB/cJ) F1 hybrid mice with increased mRNA c-myc expression. RESULTS: Since 5 out of 14 (35.7%) cases had no extra copy numbers of c-myc, gene amplification was obviously not the cause of c-myc over-expression in these tumours. In the remaining 9 tumours, c-myc over-expression was also accompanied with extra DNA copy numbers. Therefore, c-myc amplification might be a consequence of the genomic instability subsequent to the up-regulation of c-myc. However, linear regression analysis showed a lack of correlation between increasing DNA copy numbers and mRNA over expression of c-myc in these tumours (r = 0.029, p = 0.94). CONCLUSION: De-regulation of c-myc does not necessarily imply amplification of this gene in these tumours. This report is, to our knowledge, the first one comparing c-myc amplification with expression in lymphomas of the T-cell lineage.