Peripheral T-cell lymphomas: histologic, immunohistologic, and clinical characterization.

Area of Science:

• Hematology
• Oncology
• Immunology

Background:

• Peripheral T-cell lymphomas (PTCLs) present diverse clinical and histological features.
• Conventional classification of non-Hodgkin's lymphomas is challenging for PTCLs.
• Extranodal involvement is common in PTCLs at initial presentation.

Purpose of the Study:

• To review and classify 40 cases of PTCL identified institutionally.
• To investigate the immunologic and histologic characteristics of PTCLs.
• To determine if previously described entities are distinct variants of PTCL.

Main Methods:

• Retrospective review of 40 PTCL cases (March 1983 - December 1985).
• Histomorphologic analysis using conventional criteria for non-Hodgkin's lymphomas.
• Immunologic methods to identify B-cell and T-cell antigens.

Main Results:

• PTCLs showed significant clinical, histological, and immunological diversity.
• Extranodal manifestation occurred in 52% of cases.
• Four distinct subgroups were identified: angioimmunoblastic lymphadenopathy, lymphomatoid granulomatosis, Hodgkin's-like disease, and Lennert's lymphoma.
• Immunologic studies confirmed angioimmunoblastic lymphadenopathy and lymphomatoid granulomatosis as PTCLs.

Conclusions:

• Angioimmunoblastic lymphadenopathy and lymphomatoid granulomatosis are distinct histologic variants of peripheral T-cell lymphoma.
• Conventional histomorphologic criteria are insufficient for classifying all PTCLs.
• Immunologic phenotyping is crucial for accurate PTCL diagnosis and classification.