RESUMO
Microsatellite instability (MSI) has a therapeutic and prognostic implication in colorectal carcinomas (CRCs). It can be detected either by immunohistochemistry (IHC) or molecular studies. In developing countries, a significant proportion of the patients experience financial constraints limiting the utilization of healthcare facilities. We aimed to identify the possible clinicopathological variables which can be used as predictors of microsatellite instability in such patients. CRC cases received for MSI detection by IHC (for 1 and 1/2 years) were included. A panel of four IHC markers (anti-MLH1, anti-PMS2, anti-MSH2, and anti-MSH6) was used. Confirmation by the molecular study was recommended in all the IHC-proven MSI cases. Various clinicopathological parameters were evaluated as predictors of MSI. Microsatellite instability was detected in 40.6% (30/74) cases with MLH1 and PMS2 dual loss in 27% cases, MSH2 and MSH6 dual loss in 6.8%, loss of all four MMR proteins in 2.7%, and isolated PMS2 loss in 4.1%. MSI-H expression was shown by 36.5% cases with only 4.1% cases showing MSI-L expression. The age cut-off value to differentiate both the study groups (MSI vs MSS) was 63 years with a sensitivity of 47.7% and specificity of 86.7%. ROC curve showed an area under the curve of 0.65 (95% CI, 0.515-0.776; p-value = 0.03). On univariate analysis, age < 63 years, colon site, and absence of nodal metastasis were significantly higher in the MSI group. However, on multivariate analysis, only the age < 63 years was found to be significantly higher in the MSI group. Confirmation was molecular study could only be obtained in 12 cases and was completely concordant with MSI detection by IHC. MSI detection can be performed either by IHC or by molecular study. In this study, no histological parameter appeared to be the independent predictor of MSI status. The age < 63 years might predict the microsatellite instability, yet larger studies are needed for its validation. Thus, we recommend that IHC testing should be performed in all CRC cases.
RESUMO
BACKGROUND: Celiac Disease involves the small intestine patchily affecting more frequently the proximal small bowel but the histological changes have been observed till terminal ileum. Of late in addition to D2, the duodenal bulb (D1 region) biopsies have been found helpful in identifying a small group of patients with CD. Therefore, multiple site biopsies are recommended as histological changes are not uniform throughout small intestine. METHODS: During this present 1.5 years prospective study, we evaluated 84 cases of suspected celiac disease with respect to the light microscopy (D1, D2, and D3 biopsy) and serology (anti tTg and or EMA). Histological examination was done according to Modified Marsh grading system. RESULTS: Out of 84 cases with raised anti tTg, the segmental biopsies significantly increased the diagnostic accuracy from 39/44 cases (88.6%) to 43/44 cases (97.7%) and 44/44 cases (100%) when D2 alone, D1 + D2 and D1 + D2 + D3 biopsies were evaluated, respectively. Of the suspected cases of celiac disease patients (tTg > 10 ULN and associated weight loss, diarrhea), additional D3 biopsy increased the diagnostic yield by 2.1%, compared to D1, D2 region biopsy and 6.38% compared to standard D2 biopsy alone. Of the 28 cases (tTg > 10 times ULN + EMA positive and associated weight loss, diarrhea), the potential celiac disease (histologically Type 1/Normal) cases reduced from 28.5% (standard D2 region alone) to 21.4% and 17.8% when additional biopsies were taken from D1 region and D3 region, respectively, and additional D3 biopsy increased the diagnostic yield by 10.8% (compared to standard D2 biopsy alone) and 3.7% (compared to D1 and D2 biopsy). CONCLUSION: We believe multiple sites duodenal biopsies including D3 region biopsies might increase the diagnostic accuracy of adult celiac disease in addition to sensitive and specific serologic tests.
