ABSTRACT
The deficiency of mismatch repair system is one of the main pathways in colorectal cancer. This system consists mainly of four proteins: MLH1, MSH2, MSH6 and PMS2. Colorectal cancer develops in the majority of cases from precancerous lesions called adenomas. Only few studies have reported on the deficiencies of these proteins in adenomas. In this study we used immunohistochemistry staining in colorectal adenomas to assay functional status of MLH1, MSH2, MSH6, and PMS2 proteins. 102 adenomas from 93 patients were collected in our institution during six years [2007-2012]. The immunohistochemical technique was performed with 4 antibodies: MLH1, MSH2, MSH6 and PMS2. The loss of expression was retained if adenomatous cells were not stained with positive internal control. Staining was considered as abnormal if nucleus of adenomatous cells showed low nuclear staining and / or heterogeneous one, while positive internal control had normal staining. Loss of expression of MSH2 and MSH6 in adenomatous cells was found in only 1 case which was a tubular adenoma 3mm high-grade dysplasia. Abnormal staining of the adenomatous cells was noted in 23 cases [22.5%] for MSH2 and in 8 cases [7.8%] for MSH6. No cases showed loss of expression of MLH1 and PMS2. Abnormal expression of MSH2 and MSH6 was not correlated with sex of patients, the location of the adenoma, its grade of dysplasia and its histological type. Loss of Mismatch repair proteins expression is a rare event in adenomas. However, the abnormal expression levels are higher in our study compared to those reported in the literature. This could reflect a higher rate of microsatellite instability in our patients. Multicenter and larger studies with molecular biology techniques are needed
ABSTRACT
Renal cell tumours are numerous and heterogeneous. Because of their clinicopathological heterogeneity, their accurate diagnosis may be challenging. In case of an equivocal diagnosis, immunohistochemistry may be a useful mean of diagnosis. Recently, alpha-methyl CoA racemase has been identified as a useful marker in kidney cancers. Our objectives are to highlight the role of alpha-methyl CoA racemase [AMACR] as a diagnostic marker in papillary renal carcinoma and to assess its utility in the other tumour types. A retrospective review was performed on 62 patients who were treated for renal tumours between January 1994 and November 2005. Immunoreactivity was evaluated with a qualitative manner. Positive AMACR staining was defined as a coarse dense cytoplasmic granularity. The 62 renal tumours were diagnosed as papillary tumours in 22 cases, clear cell tumours in 18 cases, chromophobe carcinoma in 12 cases and oncocytoma in 10 cases among the 22 cases of papillary tumours, all the cases [100%] showed cytoplasmic immunoreactivity staining. 4 cases between the 18 clear cell carcinomas [22%] showed positivity with AMACR. The 12 cases of chromophobe carcinoma didn't express AMACR by immunohistochemistry. Only one case between the oncocytomas [1%] expressed AMACR. This study confirms the high sensitivity of AMACR for papillary renal cell carcinomas but we must keep in mind that weak focal AMACR staining could be present in other renal cell carcinomas
ABSTRACT
Hepatic localization of non Hodgkin's lymphoma is generally secondary. Primary localizations are rare.To report a rare case of primary hepatic lymphoma particular by its association with dermatopolymyositis. A 55-year-old woman with a past medical history of dermatopolymyositis diagnosed one year before presented with abdominal pain and fever. Laboratory tests showed pancytopenia. Radiologic examination revealed multiple hepatic masses. Surgical biopsy revealed a large B cell hepatic lymphoma. No other localizations were found so the diagnosis of primary hepatic lymphoma was retained. The patient died after a few days due to a severe sepsis. Primary hepatic lymphoma is a rare tumor with a bad prognosis. Its diagnosis is based on histologic examination. Treatment of these tumors remains non consensual