Characteristic molecular abnormalities are expressed by a number of these mature B cell lymphomas. T cell lymphoma may arise in the setting of celiac sprue, notably type I enteropathy-associated T cell lymphoma (EATL) (8). Molecular studies for T cell gene rearrangement confirm clonal evolution of

malignant neoplastic T cells. Extranodal NK/T cell lymphoma (ENKTL) of the GI tract is commonly associated with Epstein-Barr virus (EBV) infection and demonstrates aggressive clinical behavior and thus, like most T cell lymphomas, confers a poor prognosis (9). On the other hand, a few cases of benign, indolent Inhibitors,research,lifescience,medical and EBV negative, NK-cell http://www.selleckchem.com/products/PD-0332991.html lymphoproliferative disorder/enteropathy or lymphomatoid gastropathy, a recently described entity, have been documented (10,11). Other hematopoietic neoplasms may also involve the GI tract although incidence is extremely rare compared to mature B cell lymphomas. These include but are not limited to extramedullary plasmacytoma (EMP) (12,13), or primary amyloidosis associated with Inhibitors,research,lifescience,medical myeloma (14), plasmablastic lymphoma (PBL) (15,16), Hodgkin lymphoma (HL) (17,18), histiocytic sarcoma (HS) (19-21)

and mast cell sarcoma (MCS) (22,23). This review concentrates on the selected primary GI tract lymphomas as mentioned, focusing on Inhibitors,research,lifescience,medical the characteristic morphologic, immunophenotypic and molecular or cytogenetic features, Inhibitors,research,lifescience,medical with a brief description of a few selected hematopoietic malignancies, other than lymphoma, that may also be encountered in the GI tract. Clinical findings Symptoms may vary from each patient who may present with any or combination of any of the following: dyspepsia, epigastric pain, abdominal pain, nausea, vomiting, diarrhea, weight loss, malabsorption

(8), Inhibitors,research,lifescience,medical obstruction, anemia, and to a lesser extent ulceration, perforation (2,21) and intussusception (24,25). Hematochezia has been reported in some patients who were later diagnosed with rectal lymphoma. Conversely, a few patients were reportedly asymptomatic (10). Imaging On endoscopy, lymphoma may be nodular similar to a reactive lymph node or manifest as mucosal ulceration, hyperplasia, polyp, or as an infiltrative lesion (26). In rare occasion, lymphoma can present as incidental thickening of GI luminal wall on computed tomography (CT) (27). Biopsy is frequently performed on mucosal mafosfamide abnormalities as it is difficult to differentiate neoplastic lymphoid nodules from benign reactive follicles or mucosal polyps. Endoscopic ultrasonography (EUS) demonstrates four types of patterns indicative of gastric lymphoma: superficially spreading, diffusely infiltrating, mass forming and mixed. Low-grade MALT lymphoma characteristically appears as a superficially spreading or diffusely infiltrative lesion (28).