ABSTRACT
Background: Gastrointestinal stromal tumors - commonly called GISTs - are rare; yet, they represent an important type of mensenchymal tumors arising within the gastrointestinal tract. The acronym GIST was introduced in 1998 to define a well established pathological entity which bears a highly specific marker called KIT [CD117]. Scientific interest for these tumors in recent years is mainly due to the progress in identification by immunohistochemistry and the advent of targeted molecular therapy
Aim: To reclassify mesenchymal tumors of the digestive tract using advanced immunophenotyping
Methods: We examined the digestive tissue tumors operated at the Principal Military Hospital of Instruction of Tunis over a 19-year period from 1992 to 2011
Results: We collected 22 cases of benign mesenchymal tumors of the digestive tract. Tumors were initially diagnosed as leiomyomas [4 cases], schwannomas [2 cases], gastrointestinal stromal tumors [14 cases], a leiomyoblastoma and a mesenchymal tumor with fusiform cells. The immunohistochemical study has allowed to correct some diagnoses and, in one case, the block has been exhausted. In total, we selected 18 cases of gastrointestinal stromal tumor, a schwannoma and two leiomyosarcomas among 21 mesenchymal tumors. The final diagnosis of GIST was confirmed by the positivity of C-kit or DOG1
Conclusions: The combined use of C-kit and DOG1 ensures accurate diagnosis of GIST. The DOG1 has allowed us to detect the 3 stromal tumors negative for C-kit. This antibody has achieved a diagnostic gain of 15%. The rate of GIST tumors labeled increased from 71% to 86% among mesenchymal tumors
ABSTRACT
Study the expression of the following immunohistochemical markers in Tumours of the bladder: Proliferating Cell Nuclear Antigen [PCNA], Ki67 antigen [MIB1], the C-erbB2 proto- antigene, the tumor suppressor gene p53, the receptor for epidermal growth factor [EGF-R], the apoptosis suppressor gene bcl2, the carcinoembryonic antigen [CEA] and epithelial membrane antigen [EMA]. Study of retrospective series of 30 patients having tumours of the urinary bladder. The expression of PCNA with a cut-off value of 14% is correlated with recurrence [P = 0.010]. The expression of PCNA with a cut-off value of 1% is correlated with tumour stage [P = 0.003]. The expression of MIB1 with a cut-off value of 47% is correlated with recurrence [P = 0.010]. The expression of MIB1 with a cut-off value of 47% is correlated with the tumour progression in stage and/or in grade [P = 0.007]. The expression of C-erbB2 with a cutoff value of 28% is correlated in the tumour grade [P = 0.007]. The other antibodies didn't demonstrate a prognostic value. MIb1 and PCNA being correlated with recurrence, they can be useful with the decision of the rhythm of the endoscopy. The correlation of C-erbB2 with the tumour grade could serve to better graduating bladder tumours