Acute intestinal pseudo-obstruction after induction treatment of relapsed acute promyelocytic leukemia with arsenic trioxide.

Arsenic trioxide (As(2)O(3)) is an effective agent for the treatment of relapsed acute promyelocytic leukemia (APL). We report a patient with intestinal pseudo-obstruction, which occurred while treating relapsed APL with As(2)O(3). A 6-year-old female with relapsed APL developed paralytic ileus, hyperleukocytosis, and a high fever while being treated with As(2)O(3). Although As(2)O(3) was discontinued and dexamethasone was administered, vomiting and abdominal distension worsened. An ileostomy was performed and diffuse patch-like infiltrations on the bowel surface were noted. Pathologic findings revealed APL cells involving the entire intestinal layers. This case history suggests that As(2)O(3) when used for reinduction therapy for APL may adversely affect the intestine and cause acute intestinal pseudo-obstruction.