Immunoproliferative small intestinal disease: prolonged 30-year course without development of lymphoma.

Immunoproliferative small intestinal disease (IPSID) is mostly found in young adults of low socioeconomic class in developing countries. This condition is characterized by a dense lymphoplasmacytic infiltrate beneath the epithelium in the duodenal and proximal jejunal mucosa and in the mesenteric lymph nodes. In two thirds of cases, the involved lymphocytes elaborate an anomalous alpha-heavy chain protein. The etiology of this disease is unclear, although various parasitic, genetic, and toxic mechanisms have been proposed. Half of all IPSID patients will be found at diagnosis to have a concurrent intestinal B-cell lymphoma, and most of the remaining patients develop frank lymphoma within a few years. Although most reports of IPSID are from developing nations or indigent immigrant populations within Western countries, four cases of an IPSID-like condition have been documented in white women. Furthermore, although many IPSID patients progress to high grade indeterminate-type lymphoma within a few years of initial presentation, there have been occasional reports of long term survival without lymphomatous conversion. Here, we present an atypical case of IPSID--a California native who, though of Mexican heritage, had resided in the United States his entire life and did not belong to an indigent population. This patient had biopsy-proven IPSID that progressed over 30 yr but never exhibited lymphomatous conversion despite end stage intestinal stasis and recurrent obstruction, culminating in death. Our case calls into question some current assumptions about the prelymphomatous nature of this disease.