Immunoproliferative small intestinal disease: a study of 13 cases with alpha heavy-chain disease.

The pathology of 13 cases of immunoproliferative small intestinal disease (IPSID) associated with alpha-heavy-chain disease--one an apparent non-secretor and another with localized infiltration--is described. Four cases exhibited immunohistological light-chain monotypia. In one of these, evolution of a light-chain negative cell population was observed over a 7-year period. In the intestine, centrocyte-like cells produced lympho-epithelial lesions in 11 cases and enlarged lymphoid follicles in three. In lymph nodes, perifollicular infiltration was observed in 11 cases and abnormal follicles in six. Of three patients with high-grade lymphoma at presentation, one died untreated at 2 months, and two are alive at 34 and 91 months. Of 10 patients with low-grade disease at presentation, two died--one at 76 months, the other after transforming to high-grade lymphoma at 73 months. Eight patients with low-grade disease are alive, an average of 67 months after presentation. Four of five conservatively treated low-grade cases (including three in remission) showed evidence of monoclonality at presentation (light-chain monotypia in two and gene rearrangement in two), while two of the five exhibited DNA aneuploidy. It is concluded that IPSID with alpha-heavy-chain disease is neoplastic in all its stages and is a variant of mucosa-associated lymphoma. The role of centrocyte-like cells and the response to conservative therapy are discussed.