So-called "Lennert's lymphoma": is it a clinicopathologic entity?

Area of Science:

• Hematology
• Oncology
• Pathology

Background:

• The term "Lennert's lymphoma" has been used to describe lymphomas with a high content of epithelioid histiocytes.
• Its precise clinicopathologic definition and natural history remain subjects of investigation.

Purpose of the Study:

• To investigate the natural history of "Lennert's lymphoma".
• To reevaluate whether non-Hodgkin's lymphoma with abundant epithelioid histiocytes constitutes a distinct clinicopathologic entity.

Main Methods:

• Retrospective review of histopathologic and clinical features of 60 patients.
• Analysis of pretreatment diagnostic tissues showing epithelioid histiocytic reaction.

Main Results:

• "Lennert's lymphoma" comprised Hodgkin's disease (27 patients), non-Hodgkin's lymphoma (24 patients), angioimmunoblastic lymphadenopathy (1 patient), and atypical lymphoepithelioid cell proliferations (8 patients).
• Hodgkin's disease patients typically had early-stage disease without B symptoms and a median survival of 79 months.
• Non-Hodgkin's lymphoma patients often presented with advanced-stage disease and B symptoms, with a median survival of 12 months.
• Non-Hodgkin's lymphoma with epithelioid histiocytes showed distinct macroscopic and microscopic features and appears to be a separate entity.

Conclusions:

• "Lennert's lymphoma" is a heterogeneous group, not a single disease entity.
• Non-Hodgkin's lymphoma characterized by a multifocal epithelioid histiocytic reaction is a distinct clinicopathologic entity.
• This distinct entity has a significantly poorer prognosis compared to Hodgkin's disease within the "Lennert's lymphoma" spectrum.