Burkitt lymphoma-induced ileocolic intussusception in Wiskott-Aldrich syndrome.

A 12-year-old patient with Wiskott-Aldrich syndrome (WAS) was referred because of recurrent abdominal pain and bloody stools. Ileocolic invagination was diagnosed and resection of the terminal ileum was performed. Pathologic examination identified submucosal tumor as the leading point of intussusception. Immunohistochemistry confirmed the diagnosis of Burkitt lymphoma. The use of chemotherapy with anti-CD20 monoclonal antibody led to complete clinical remission of lymphoma. Non-Hodgkin's lymphoma (NHL) accounts for more than 60% of the tumors in children with primary immunodeficiency, and it is the most common type of malignancy observed in WAS. Burkitt lymphoma represents 40% to 50% of all NHL cases in childhood, but in WAS it has rarely been reported. Mutation analysis of the WASP gene in this patient revealed missense mutation (105 C > T) in exon 1. WAS protein (WASP) of normal size was present at a reduced amount in peripheral blood lymphocytes. Complete lack of expression of WASP carries a greater risk for severe infections, bleeding, or malignancy development in WAS. However, rare patients with residual expression of mutated WASP, like this patient, still may develop lymphomas.