Influence of translocation t(11;18) on response to conservative treatment of MALT gastric lymphoma (MGL)

phage COX-2 expression was also determined. Results: All of the tumors were c-kit positive confirming the diagnosis of GIST. Eighty percent (12/15) of the tumors expressed COX-2. Expression was noted in the cytoplasm of the tumor cells. There was heterogeneity of intensity of staining between the tumors. COX-2 was expressed in both epithelioid and spindled tumors, but appeared stronger in epithelioid lesions. In mixed lesions, COX-2 was expressed to a greater extent in epithelioid areas. There was a higher degree of COX-2 expression in malignant tumors and those located in the stomach. CD68 positive cells were identified in all of the lesions and in 80% of cases, these ceils also expressed COX-2. in 2 of the 3 GISTs that were COX-2 negative, macrophages expressed COX-I Conclusions: In this study, for the first time, we have demonstrated expression of COX-2 in stromal lesions of the gastrointestinal tract. The enzyme may have a role in the proliferation of these lesions, which suggests the potential use of COX-2 inhibitors for treatment of these tumors.