Unusual manifestation of B-cell acute lymphoblastic leukemia in a 16-year-old boy with gastric ulcer caused by blast infiltration

We present the case of a 16-year-old boy diagnosed with B-cell acute lymphoblastic leukemia and leukemic infiltration of the stomach. Two months prior to diagnosis, the patient had suffered from upper abdominal pain with vomiting, melena, increasing tiredness accompanied by weight loss of 12kg and night sweat. He presented to a local hospital where a stenosing pyloric ulcer was diagnosed by gastroscopy. Biopsy specimen were taken and consistent with chronic inflammatory changes. Colonization with Helicobacter pylori was found and eradication therapy was initiated. However, two months later the patient presented with recurrent acute exacerbation and worsening clinical condition. At this point, another biopsy revealed identical results. MRI of the whole abdomen was performed which showed not only thickening of the gastric wall but also hepatosplenomegaly with peritoneal and pleural effusion. Moreover, generalized hyperintensity of the bone marrow was noted. The boy was then referred to our center and a bone marrow aspirate was performed revealing infiltration with 90% blasts. Morphology and immunophenotype were consistent with B-cell acute lymphoblastic leukemia. Cytogenetics verified a MYC t(8;14)(q24;q32) rearrangement. Retrospectively, blast infiltration was also found in the initial gastric and duodenal biopsy material. Chemotherapy according to the NHL-BFM 2004 protocol with an upfront rituximab window was initiated. Since gastric ulceration without obvious intake of damaging substances is rare in children and adolescents, a broad work-up is warranted, including leukemia as a differential diagnosis.