RESUMO
More than 90% of synovial sarcomas (SSs) possess a non-random chromosomal translocation t(X;18)(p11;q11) and express SYT-SSX fusion gene products originating from the translocation. To test whether it is possible to detect the SYT-SSX mRNA on archival formalin-fixed paraffin-embedded SS tissue sections using PCR-based in situ amplification technique, we performed reverse transcription-polymerase chain reaction in situ hybridization (RT-PCR ISH) for the SYT-SSX fusion gene mRNA. In three types of SSs, monophasic fibrous, biphasic and poorly differentiated, NBT/BCIP signals corresponding to SYT-SSX mRNA were uniformly and predominantly positive in the sarcoma cell cytoplasm. Our results indicated that SS cells uniformly possessed the SYT-SSX fusion genes and expressed their transcripts. Furthermore, our results were thought to support monoclonal origin of epithelial and spindle cell components of biphasic SSs. Thus, specific chromosomal translocation t(X;18) is likely to be an early event in the development of SSs, and the expression of SYT-SSX fusion gene products is thought to be crucial for the tumorigenesis of SSs.
Assuntos
Hibridização In Situ/métodos , Proteínas de Fusão Oncogênica/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Sarcoma Sinovial/genética , Humanos , Imuno-Histoquímica , Queratinas/análise , Mucina-1/análise , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reprodutibilidade dos Testes , Sarcoma Sinovial/metabolismo , Sarcoma Sinovial/patologia , Vimentina/análiseRESUMO
AIM: To clarify CT and MR features of nasopharyngeal carcinoma (NPC) in children and young adults. METHOD: CT and MR findings of 13 patients (30 years old or younger) with a histopathologic diagnosis of NPC were reviewed. RESULTS: Skull base invasion (12/13), lymphadenopathy (10/13), and infiltrative growth (8/8) were common findings. The signal intensity of tumours was slightly higher than that of muscles in six cases and isointense to that of muscles in two cases on T1-weighted images; it was higher than that of muscle and lower than that of cerebellar grey matter on T2-weighted images in all cases. Internal signals were homogeneous in both pre- and post-Gd-enhanced MR images in all cases. CONCLUSIONS: Despite its rarity in this age group, NPC should be included in a differential diagnosis when CT and MR imaging reveal these features.