Primary Macroglobulinemia: Death due to Mesenteric Vascular Occlusion with Gas in the Portal Venous System

Clinical features presented by a patient with primary macroglobulinemia over a four-year period included cachexia, weight loss, bleeding tendency, anemia, lymphadenopathy, hepatosplenomegaly and recurrent pulmonary bacterial infections. Immunoelectrophoresis demonstrated the presence of a β₂ macroglobulin which, on ultracentrifugation, was found to have a sedimentation constant of 14.9 S₂₀, w; this macroglobulin constituted over 40% of the total serum protein. Postmortem findings included the typical “naked” lymphocyte infiltration of the reticuloendothelial system, with septic embolization from a terminal Gram-negative bacteremia, associated with a mesenteric vascular occlusion. A feature of particular interest was the antemortem appearance of gas in the portal venous system, shown on two abdominal scout radiographs taken one and two hours before death. The diagnostic significance of this rare radiologic sign is discussed.