[Extramedullary relapse of acute lymphoblastic leukemia in the mastoid after allogeneic hematopoietic stem cell transplantation: a case report].

Extramedullary relapse of acute lymphoblastic leukemia (ALL) in the mastoid after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is rare. In this paper, we describe such an uncommon case of extramedullary relapse of ALL in the mastoid. The patient, who had been diagnosed as having ALL and underwent an allo-HSCT from his matched sibling donor. Eight months after allo-HSCT, he presented with ear-ache, tinnitus. The middle ear mastoid CT revealed otomastoiditis. The patient underwent operation. After pathological examination, the definited diagnosis was made that the patient was extramedullary relapse of ALL in the mastoid. We should pay more attention to the patients with hemopathy, which can help to improve early diagnosis.