[Case #2. High-grade B-cell lymphoma with 11q aberration: A case report]

High-grade B-cell lymphoma with 11q aberration (HGBL-11q) is a recently recognized entity according to the 2022 WHO classification that often morphologically and immunohistochemically resembles Burkitt lymphoma but has distinct molecular characteristics. In HGBCL-11q, the defining abnormality is a characteristic gain/loss pattern of chromosome 11q without MYC rearrangement, whereas Burkitt lymphoma is characterized by a classical MYC rearrangement with one of the three immunoglobulin genes. HGBL-11q is a rare lymphoma that predominantly affects children and adolescents. Clinically, patients typically present without B symptoms. The disease most commonly involves lymph nodes in the head and neck region (approximately 60-70% of cases), while gastrointestinal involvement is observed in about 30-40% of patients.