Case report: rectal stenosis due to extramedullary haemopoiesis--radiological features.

Although extramedullary haemopoiesis (EMH) is relatively common in myelofibrosis, it is seldom symptomatic and rarely involves the intestinal tract. We report a case in which perirectal infiltrate resulted in clinically symptomatic constipation. The barium enema showed tubular rectal narrowing with mucosal pleating. On computed tomography a poorly marginated soft tissue mass was shown to be replacing the perirectal fat.