RESUMO
Microscopic colitis (MC) is a chronic inflammatory disease of the colon that presents with chronic, nonbloody watery diarrhea and only few or no endoscopic abnormalities. Histologic examination discriminates lymphocytic colitis (LyC; presence of ≥20 intraepithelial lymphocytes per 100 surface epithelial cells) and collagenous colitis (CC; colonic subepithelial collagen band >10 µm in diameter).1,2 MC not otherwise specified describes a subgroup of patients who do not fulfill the diagnostic criteria for either CC or LyC.1,2 Population-based epidemiologic data regarding MC are scarce. We aimed to evaluate the clinical presentation at diagnosis, incidence, and prevalence of MC in Cantons of Vaud and Fribourg, Switzerland.
Assuntos
Colite Colagenosa , Colite Linfocítica , Colite Microscópica , Colite , Estudos de Coortes , Colite Microscópica/diagnóstico , Colite Microscópica/epidemiologia , Humanos , Incidência , Suíça/epidemiologiaRESUMO
Colorectal cancer with microsatellite instability (MSI) may occur sporadically or be inherited in cases of hereditary nonpolyposis colorectal cancer (HNPCC) syndrome. However, there is no consensus as to which patients must be tested and how to test MSI. In this study, MSI was tested by immunohistochemical analysis and by polymerase chain reaction in 148 cases of colorectal cancer, and methylation of the hMLH1 promoter was examined. MSI status was correlated with tumor phenotype. We found that localization, tumor infiltrating lymphocytes, and mucinous differentiation were predictive of high-frequency MSI (MSI-H) colorectal cancer and might be used to select cases for MSI analysis. Immunohistochemical analysis detected most MSI-H colorectal cancer and might constitute the first step in MSI detection. Absence of hMLH1 promoter methylation in MSI-H colorectal cancer could be predictive of hereditary colorectal cancer, and, hence, methylation analysis might constitute the second step in the identification of patients with HNPCC.
Assuntos
Algoritmos , Proteínas de Transporte/genética , Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Repetições de Microssatélites/genética , Técnicas de Diagnóstico Molecular/métodos , Proteínas Nucleares/genética , Proteínas Adaptadoras de Transdução de Sinal , Idoso , Estudos de Coortes , Neoplasias Colorretais Hereditárias sem Polipose/genética , Análise Custo-Benefício , Análise Mutacional de DNA , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Técnicas de Diagnóstico Molecular/economia , Proteína 1 Homóloga a MutL , Reação em Cadeia da PolimeraseRESUMO
A clear cell sarcoma, arising primarily in the ileum of a 35-year-old man, is reported. Histologically, the neoplasm infiltrated the full thickness of the intestinal wall. It consisted of strands and sheets of round to spindle-shaped cells with clear to eosinophilic cytoplasm, vesicular nuclei and prominent nucleoli. Vascular invasion was present at diagnosis. Tumour cells expressed S-100 protein, melan-A and tyrosinase. They were negative for HMB45, CD117, cytokeratins, epithelial membrane antigen, smooth muscle actin, desmin, CD31, CD34, chromogranin and synaptophysin. Reverse transcription-polymerase chain reaction analysis performed on paraffin-embedded tissue showed EWS-ATF1 fusion transcripts representative of the t(12;22) (q13;q12) clear cell sarcoma reciprocal translocation. The patient, who developed liver metastases 2 months after diagnosis, died of disease at 15 months. This case demonstrates that the gastrointestinal tract is a potential site for primary clear cell sarcoma of soft tissues, and, furthermore, that cytogenetics and/or molecular techniques play a central role in the diagnosis.