CT appearances of mucosa-associated lymphoid tissue (MALT) lymphoma

Mucose-associated lymphoid tissue (MALT) lymphoma is a low-grade lymphoma t hat differs from high-grade non-Hodgkin lymphoma both clinically and histol ogically. The CT appearances of MALT lymphoma are described, Of 40 patients referred with biopsy-proven MALT lymphoma, only, seven had not had gastrec tomy or chemotherapy prior to CT examination. The CT scans of these seven c ases were analysed for the degree and extent of gastric wall thickening, en largement of abdominal and extra-abdominal lymph nodes, and presence of ext ra-nodal disease. In all patients the stomach was distended with oral contr ast medium and scans performed at narrow collimation, after intravenous adm inistration of 20 mg hyoscine butylbromide. In six patients focal thickenin g of the gastric wall was 1 cm or less. One patient had thickening of over 4 cm. There was no enlargement of abdominal or extra-abdominal lymph nodes or extension to adjacent organs. Thus on CT, at presentation, MALT lymphoma results in minimal gastric wall thickening, unlike high-grade non-Hodgkin lymphoma, which typically causes bulky gastric disease, nodal enlargement a nd extension into adjacent organs. CT is therefore of limited value in moni toring response to treatment. With disease greater than minimal thickening, transformation to a higher grade should be considered.