Atypical angioimmunoblastic T-cell lymphomas masquerading as systemic polyclonal B-immunoblastic proliferation.

Area of Science:

• Hematology
• Oncology
• Immunology

Background:

• Angioimmunoblastic T cell lymphoma (AITL) is a rare peripheral T cell lymphoma originating from follicular T helper cells.
• AITL presents with diverse clinical and morphological features, often challenging diagnosis.
• Neoplastic cells in AITL can be obscured by reactive polyclonal B immunoblasts and plasma cells.

Observation:

• AITL-associated B cell and plasma cell proliferation results from cytokine dysregulation, notably interleukin-6, by neoplastic T cells.
• Systemic polyclonal B immunoblast and plasma cell proliferation characterizes SPBIP, a condition with unknown etiology.
• Two AITL cases exhibited atypical features resembling SPBIP, complicating initial diagnosis.

Findings:

• The reported AITL cases demonstrated unusual presentations that mimicked SPBIP.
• Diagnostic difficulty arose from the complex cellular infiltrates in these AITL cases.
• The study underscores the overlap in presentation between AITL and SPBIP-like conditions.

Implications:

• These findings emphasize the necessity of considering AITL in the differential diagnosis of polyclonal plasmacytosis and SPBIP.
• Screening patients with SPBIP-like presentations for underlying AITL is recommended.
• Improved diagnostic strategies are needed for challenging AITL cases with atypical features.