Long-term remission after surgical excision and minimal rituximab exposure in localized high-grade B-cell lymphoma with 11q aberration

Abstract

High-grade B-cell lymphoma with 11q aberration (HGBCL-11q) is a mature B-cell neoplasm that resembles Burkitt lymphoma (BL) but lacks MYC rearrangement and is characterized by a distinct pattern of 11q gain and loss abnormalities. Although most reported cases have been treated with intensive chemotherapy, the clinical behaviour of localized disease remains poorly understood. We report a localized case of HGBCL-11q in a young woman who has remained in durable remission for 8.5 years after complete surgical excision, with only limited exposure to rituximab and no further systemic therapy. Histologically, the tumour showed high-grade morphology intermediate between BL and diffuse large B-cell lymphoma (DLBCL), with diffuse growth, a prominent starry-sky appearance, high MYC expression, and a high proliferative index. The tumour exhibited a germinal center B-cell (GCB) phenotype but lacked MYC rearrangement, arguing against BL. DLBCL, NOS remained in the differential diagnosis because of the intermediate morphology and GCB phenotype and was considered the most likely diagnosis at the time, although the overall clinicopathological findings were atypical. Paediatric-type follicular lymphoma was also considered because of the localized presentation and GCB phenotype, but the absence of centrocyte-like cells and follicular architecture, together with diffuse growth, argued against this diagnosis. Subsequent fluorescence in situ hybridization demonstrated gain of 11q23.3 and loss of 11q24.3, establishing the diagnosis of HGBCL-11q. This case suggests that some patients with completely resected localized HGBCL-11q may maintain long-term remission without intensive chemotherapy despite aggressive histological features.