Childhood de novo CD5+ Diffuse Large B-cell Lymphoma: a Separate Entity?

De novo CD5-positive diffuse large B-cell lymphoma (CD5+ DLBCL) is a subtype of DLBCL found predominantly in older individuals. This particular subtype has been associated with a female predominance and a more aggressive clinical course. Conversely, this entity has not been described in the pediatric population. We report a case of a 12 year-old boy who presented with an ileocecal intussusception. Radiologic, morphologic, and immunophenotypic analysis revealed an isolated extranodal mass consistent with a CD5+ DLBCL, germinal center cell phenotype. Fluorescent in situ hybridization analysis was negative for cMYC, BCL6, BCL2, MLL, and IGH/CCND1 rearrangement and showed loss of one copy of MLL in 32% cells. The patient was treated with four cycles of cyclophosphamide, vincristine, prednisolone, methotrexate, and doxorubicin and achieved complete remission. To the best of our knowledge, this is the first detailed report of a de novo CD5+ DLBCL occurring in a child.