Extramedullary Involvement of the Ascending Colon in Relapsing Acute Lymphocytic Leukemia: A Case Report.

Acute lymphoblastic leukemia (ALL) accounts for <1% of adult cancers. Extramedullary relapse of ALL has been primarily reported in pediatric patients or hematopoietic stem cell transplant recipients, and the gastrointestinal (GI) tract is a less frequently reported site of extramedullary relapse. Here, we report a case of a 30-year-old male who was a known case of ALL with multiple relapses and allogenic stem cell transplantations. The patient presented with acute lower GI bleeding and was confirmed to have an extramedullary relapse of ALL in the ascending colon. As the patient already had early relapses after two hematopoietic stem cell transplants in the past, he was managed with palliative chemotherapy, consisting of vincristine, dexamethasone, and rituximab, following which the patient achieved complete remission. This case highlights the importance of recognizing uncommon presentations of ALL such as those involving the GI tract.