[Molecular characterization of lynch syndrome in Tunisia]

High rates of early colorectal cancers [CRC] are observed in Tunisia suggesting genetic susceptibility. Nevertheless, up to now no molecular studies have been performed in the Tunisian population. To evaluate the clinical and genetic characteristics of Tunisian families suspected of hereditary nonpolyposis colorectal cancer [HNPCC] and to identify new tumoral markers for CRC susceptibility leading to distinguish patients with sporadic CRC from those with familial CRC, like HNPCC. 31 unrelated families suspected of HNPCC were screened for germline mutations in MMR genes. We have also analyzed tumoral phenotype and the genetic characteristics of tumors from 51 patients with CRC meeting the Bethesda criteria. 10 different germ line mutations, 8 of which were novel, were identified in 11 out of the 31 families [35.5%], 5 in MSH2 and 5 in MLH1. Our results showed that MUC5AC expression was more frequent in patients with family history of CRC [p=0.039]. The analysis of MUC5AC expression might be very beneficial in the detection of Tunisian patients with high susceptibility to CRC

utility of alpha-methyl CoA racemase [P504S] expression as a marker of renal cell carcinomas

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

[Solid pseudopapillary tumors of the pancreas: a pediatric case report]

Solid pseudopapillary tumors of the pancreas are extremely rare and mostly seen in young females. It is often diagnosed incidentally or during investigations of gastrointestinal complaints. Report of a pediatric case of this tumor. We report the case of a 15-year old teenager who presented with painful abdominal tumefaction. Imaging findings were a 12 cm solid and cystic mass originating from the tail of the pancreas. A distal pancreatectomy with splenectomy was performed. Pathologic examination concluded to solid pseudopaprillary tumor. Evolution was favorable with no recurrence 18 months after surgery. Histological examination confirms the diagnosis and allows, with the help of immunohistochemical study, to rule out some differential diagnoses such as pancreatoblastoma, acinar tumors and endocrine tumors. Prognosis of solid pseudopapillary tumors of the pancreas is excellent after radical resection and recurrences are rarely seen