Extramedullary Gastric Relapse at the Time of Bone Marrow Relapse of Acute Lymphoblastic Leukemia after Allogeneic Bone Marrow Transplantation.

Extramedullary relapse (EMR) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is relatively rare. The most commonly reported sites in acute lymphoblastic leukemia (ALL) patients after allo-HSCT are soft tissue and the central nervous system, and the gastrointestinal system is an uncommon site. We herein report a unique case with massive hematemesis resulting from gastrointestinal relapse of ALL after allo-HSCT. Upper gastrointestinal endoscopy showed bleeding from a 1.5-cm submucosal tumorous lesion with central ulceration on the anterior wall of the stomach. At the same time, computed tomography revealed extramedullary relapse at the breast and bilateral adrenal glands.