Paroxysmal nocturnal hemoglobinuria associated with venous thrombosis and 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 factor, which is a complement regulatory glycoprotein (CD55), as well as in the membrane inhibitor of reactive lysis (CD59) and the C8-binding protein. These proteins are deficient on the membranes of red blood cells, granulocytes, monocytes, and platelets. The disorder is associated with intermittent hemolytic anemia, hemoglobinuria, infection, a tendency toward bone marrow aplasia, and venous thromboses. The thromboses, on resolution, may give rise to endothelial proliferation that may cause ischemia and ulceration, or, alternatively, the thromboses may cause ulceration leading to a granulation tissue response with exaggerated endothelial proliferation. We report a second case of paroxysmal nocturnal hemoglobinuria that presented roentgenographically as an ulcerated circumferential duodenal mass secondary to venous thrombosis accompanied by florid papillary endothelial hyperplasia. We also review the literature concerning this phenomenon.