Colonic ulceration in a patient with renal disease and hyperkalemia

A noncontrast CT revealed a large heterogeneous mass measuring approximately 14×7×9 cm in the medial right thigh, extending to the midthigh. Because the patient had an elevated WBC count and had been febrile, infection was suspected. The platelet count increased to 619×103/µL and peaked at 911×103/µL. Decreases in hemoglobin and hematocrit to 6.7 g/dL and 21%, respectively, indicated worsening anemia, and the patient was transfused with packed RBCs. Because of the anemia and a history of "dark" stools while in the hospital, the patient underwent colonoscopy on hospital day 11.