PAROXYSMAL-NOCTURNAL HEMOGLOBINURIA ASSOCIATED WITH VENOUS THROMBOSISAND PAPILLARY ENDOTHELIAL HYPERPLASIA PRESENTING AS ULCERATED DUODENAL MASS

Paroxysmal nocturnal hemoglobinuria is an acquired clonal expansion of bone marrow stem cells that are deficient in the decay-accelerating f actor, which is a complement regulatory glycoprotein (CD55), as well a s in the membrane inhibitor of reactive lysis (CD59) and the C8-bindin g protein. These proteins are deficient on the membranes of red blood cells, granulocytes, monocytes, and platelets. The disorder is associa ted with intermittent hemolytic anemia, hemoglobinuria, infection, a t endency toward bone marrow aplasia, and venous thromboses. The thrombo ses, on resolution, may give rise to endothelial proliferation that ma y cause ischemia and ulceration, or, alternatively, the thromboses may cause ulceration leading to a granulation tissue response with exagge rated endothelial proliferation. We report a second case of paroxysmal nocturnal hemoglobinuria that presented roentgenographically as an ul cerated circumferential duodenal mass secondary to venous thrombosis a ccompanied by florid papillary endothelial hyperplasia. We also review the literature concerning this phenomenon.