RESUMO
Lipomas are frequently characterized by rearrangements resulting in the fusion of the HMGA2 gene (12q14.3) with a variety of partners. Chromosome band 9p22 rearrangements occur in about 1% of lipomas. We report here the molecular cytogenetic analysis of five cases of lipoma with a 9p22 aberration, including the first cytogenetic analysis of a colonic lipoma. Three out of the five cases showed a rearrangement of NFIB at 9p22.3. The NFIB rearrangement involved a fusion with HMGA2 in two cases. We have identified an in-frame fusion of the first three exons of HMGA2 with exon 6 of MSRB3 (12q14.3) and exons 8 and 9 of NFIB by using 3'RACE-PCR in a case of superficial lipoma. In a case of retroperitoneal lipoma we found a fusion of HMGA2 with NFIB by fluorescence in situ hybridization analysis. The colonic lipoma was characterized by a t(9;16;19)(p22;q21;q13) with a rearrangement of NFIB and no rearrangement of HMGA2. NFIB belongs to the nuclear factor I transcription family. It has been previously shown to be fused with HMGA2 in one case of lipoma and to be a recurrent partner of HMGA2 in pleormorphic adenoma of salivary glands. We here demonstrate that NFIB can also be rearranged independently from HMGA2, indicating a potentially important role in lipoma pathobiology. Our findings suggest that the rearrangement of NFIB might be associated with deep-seated lipomas, such as retroperitoneal or gastro-intestinal lipomas.
Assuntos
Aberrações Cromossômicas , Cromossomos Humanos Par 9/genética , Neoplasias do Colo/genética , Lipoma/genética , Fatores de Transcrição NFI/genética , Neoplasias Retroperitoneais/genética , Adulto , Idoso , Sequência de Bases , Neoplasias do Colo/patologia , Feminino , Humanos , Cariotipagem , Lipoma/patologia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Fatores de Transcrição NFI/metabolismo , Neoplasias Retroperitoneais/patologiaRESUMO
Diffuse retroperitoneal fibrosis (RPF) is a rare inflammatory process. We report on two known cases of RPF, without evidence of involvement of the urinary tract or of the venous system. A computed tomography (CT)-guided biopsy was performed in each case, and the histological findings eliminated other pathological processes, particularly those of malignant origin. In both cases, a therapy with cortisone was instituted, and a follow-up with CT at 6 months has demonstrated a regression of the pathology of more than 50%.
Assuntos
Biópsia por Agulha/métodos , Fibrose Retroperitoneal/diagnóstico , Tomografia Computadorizada por Raios X/métodos , Seguimentos , Humanos , Imuno-Histoquímica , Dor Lombar/diagnóstico , Dor Lombar/etiologia , Masculino , Pessoa de Meia-Idade , Prednisolona/uso terapêutico , Fibrose Retroperitoneal/tratamento farmacológico , Medição de Risco , Índice de Gravidade de Doença , Resultado do TratamentoRESUMO
Well-differentiated liposarcomas (WDLPS) classically contain high-level amplification of 12q14-15 sequences, including the MDM2 and CDK4 genes, while lipomas are characterized by simple structural chromosome aberrations often involving HMGA2 at 12q15. Previous studies have shown that low-level gain of the 12q14-15 region, such as trisomy 12 and 12q15-24 duplication, might be sufficient for the development of minimal atypia and formation of WDLPS. Moreover, because some features, such as overexpression of HMGA2, are shared by both lipomas and WDLPS, it has been hypothesized that lipomas and WDLPS may form a genetic and morphological continuum. We report here the results of molecular cytogenetic analysis of 8 lipomas that had unusual chromosomal features resulting in gains of 12q14-15. While 3 cases had simple numerical rearrangements (trisomy 12) or structural rearrangements (unbalanced translocations with 12q gains), 5 cases were particularly intriguing because of peculiar features such as giant chromosomes, supernumerary chromosomes or neocentromeres that usually are the hallmark of WDLPS. Gain of 12q14-15 sequences including extra copies of MDM2 and CDK4 were detected by fluorescence in situ hybridization analysis in all analyzed cases but no expression of MDM2 and CDK4 was observed suggesting that these genomic imbalances had no functional consequence. We observed rearrangements of HMGA2 in 5 out 8 cases. Altogether, our results indicate that moderate gains of 12q are not always associated with a malignant phenotype, and that some intermediary forms exist between classical lipomas and classical WDLPS. Some of these intermediary forms may correspond to a genomic premalignant condition while some may have no malignant potential.
Assuntos
Aberrações Cromossômicas , Cromossomos Humanos Par 12/genética , Lipoma/genética , Lipoma/patologia , Idoso , Idoso de 80 Anos ou mais , Bandeamento Cromossômico , Deleção Cromossômica , Quinase 4 Dependente de Ciclina/genética , Feminino , Proteína HMGA2/genética , Humanos , Hibridização in Situ Fluorescente , Cariotipagem , Lipossarcoma/genética , Lipossarcoma/patologia , Masculino , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas c-mdm2/genética , Translocação Genética , TrissomiaRESUMO
Primary rhabdomyosarcoma (RMS) of the kidney in an adult is a very rare and unusual tumor in this site. The clinical signs associated with the flank tumoral syndrome, the histologic appearance of cytoplasmic double striation in rhabdomyoblasts and the immunohistochemical expression of skeletal muscle differentiation (desmin, myoglobin, myogenin) are described in the context of a rapidly evolving renal RMS in a 77-year old man. The differential diagnosis are mainly represented by sarcomatoid renal cell carcinoma. According to the neoplastic extent, the treatment includes radical nephrectomy, chemotherapy and surgery. The prognosis of primary renal RMS is extremely poor, with lymph node, hepatic, bone marrow and pulmonary metastasis and a short survival rate.
