Concurrent low grade B-cell non-Hodgkin's lymphoma of MALT type arising in the large intestine, small intestine and stomach.

Low-grade non-Hodgkin's lymphomas (NHL) of mucosa associated lymphoid tissue (MALT) are indolent neoplasms that, although tending to remain localized for many years, may spread to other mucosal sites. Despite increasing identification of concurrent gastric and intestinal lymphoma of MALT type, the clonal relationship between the tumors and their sequential development are poorly understood. It is also unknown whether the development of these concurrent tumors is closely associated with direct antigen stimulation, which is thought to play an important role in the clonal expansion of low grade MALT lymphomas. The most important function of B-cells is production of specific antibodies. This is largely achieved during B-cell development by recombination of the Ig heavy chain variable (V), diversity (D), and joining (J) segments and hypermutation of the rearranged gene. The rearranged Ig genes of a mature B-cell record much of its evolution history. We report a case of synchronous development of intestinal and gastric low grade MALT lymphomas in a 70 years old female and discuss their possible clonal relationship and sequential appearance.