Mediterranean lymphomas with alpha heavy chain monoclonal gammopathy.

Nine cases of Mediterranean lymphoma with alpha heavy chain disease are described. All patients were young, aged between 11 and 22 years. Neither sex predominated in the series. The clinical presentation of the disease was either gastrointestinal, with chronic diarrhea and malabsorption, or neoplastic, with tumors frequently associated with either obstructive or perforative complications. Finger clubbing and retardation of physical growth (height and weight) and secondary sexual maturation were usually evident. The laboratory manifestations of the malabsorption syndrome were scant and generally not specific. The intestinal lesions predominated in the beginning of the small bowel, and their gross appearance varied from one case to another: diffuse thickening of the intestinal wall, alone or associated with tumors, or isolated segmentary tumors. Massive mesenteric lymph node enlargement was present in all cases; in some cases hepatic, splenic, or extra-abdominal lymph node spread was noted. Histologically, these lesions demonstrated a varied cellular morphology, but seemed to belong constantly to the B-lymphocytic line. The secretion and excretion by these cells of an abnormal IgA (devoid of light chains), which was revealed by immunoelectrophorectic study of the patients' sera, was the main biochemical abnormality of the disease. This disease presents several problems: 1) its relationship with other intestinal lymphomas; 2) the nature and the degree of malignancy of the intestinal cellular infiltrates; and 3) its identification as a clinicopathologic entity, with the possibility that infectious and genetic factors are significant in its etiology and pathogenesis.