Apoptosis of ileal crypt epithelia after allogeneic bone marrow transplantation without graft-versus-host disease.

Intestinal crypt cell apoptosis may occur after allogeneic bone marrow transplantation without clinically overt graft-versus-host disease. We describe this phenomenon in a case of a 12-year-old girl who had segments of the ileum resected because of a relapse of acute lymphoblastic leukemia. The diagnostic difficulties are discussed.