The pathologic anatomy of alpha chain disease.

alpha CD is an immunoproliferative disorder which is most frequently, but not always, associated with the disease entity referred to as Mediterranean lymphoma with malabsorption. In most cases, the evolution of the disease and its morbid anatomy suggests an immune deficiency state in which an abnormal clone of intestinal plasma cells incapable of producing the complete IgA molecule proliferates, perhaps in response to microbial antigenic stimulation. In the majority of cases, this proliferation is composed of mature appearing plasma cells which lack morphologic features of malignancy. Although possibly reversible, this proliferation appears to be highly susceptible to the evolution of secondary neoplastic clones, which appear in most instances after a clinical course of unpredictable duration and manifest themselves in the form of single or multiple immunoblastic sarcomas.