High-grade B-cell lymphomas with TdT expression: a diagnostic and classification dilemma

Area of Science:

• Hematology
• Oncology
• Pathology

Background:

• Distinguishing mature and immature B-cell neoplasms is crucial for appropriate therapeutic strategies.
• TdT expression in B-cell neoplasms lacking other immaturity markers poses a diagnostic challenge.
• TdT-positive aggressive B-cell lymphomas represent a heterogeneous group with poor outcomes.

Purpose of the Study:

• To describe the clinicopathologic features of 13 patients with TdT-positive aggressive B-cell lymphoma.
• To evaluate the clinical course and outcome of these patients.
• To propose a distinct classification for these challenging neoplasms.

Main Methods:

• Case series analysis of 13 patients with TdT-positive aggressive B-cell lymphoma.
• Categorization of cases based on de novo diagnosis, evolution from follicular lymphoma, or relapse with TdT acquisition.
• Review of clinicopathologic features, cytogenetics, and treatment outcomes.

Main Results:

• The 13 patients exhibited highly heterogeneous clinicopathologic features.
• Cases were grouped into de novo high-grade B-cell lymphoma with rearrangements, lymphoma evolving from follicular lymphoma, or mature B-cell lymphomas acquiring TdT at relapse.
• All patients experienced an aggressive clinical course and dismal outcome despite therapy.

Conclusions:

• TdT-positive aggressive B-cell lymphomas represent a distinct subgroup with poor prognosis.
• A descriptive term like 'high-grade B-cell lymphoma with TdT expression' is suggested over current WHO categories.
• Distinguishing these neoplasms from B-lymphoblastic leukemia/lymphoma is vital for patient management and research.