Extranodal peripheral T-cell and NK-cell neoplasms

Area of Science:

• Hematology
• Oncology
• Immunology

Background:

• Mature or peripheral T-cell lymphomas constitute 10-15% of non-Hodgkin lymphomas.
• Classification of these lymphomas has been challenging due to lack of distinct cytologic features and specific immunophenotypes.
• Clinical presentation is often paramount in defining T-cell and NK-cell neoplasms.

Purpose of the Study:

• To review the classification and key features of extranodal T-cell and NK-cell lymphomas.
• To highlight the importance of clinical characteristics in diagnosing these rare malignancies.
• To discuss associations with Epstein-Barr virus (EBV) and immune suppression.

Main Methods:

• Review of existing literature on T-cell and NK-cell lymphomas.
• Analysis of clinical, cytologic, and immunophenotypic data.
• Categorization of extranodal T/NK cell tumors based on common presentations.

Main Results:

• Most extranodal T-cell/NK-cell lymphomas exhibit a cytotoxic phenotype, potentially leading to apoptosis.
• Three primary categories of extranodal T/NK cell tumors include nasal, intestinal, and subcutaneous panniculitis-like types.
• Hepatosplenic gamma delta T-cell lymphoma represents a systemic disease of immature cytotoxic cells.
• Epstein-Barr virus (EBV) association varies by site and geography.
• Increased incidence observed in immune-suppressed individuals, particularly post-organ transplantation.

Conclusions:

• Clinical features are critical for diagnosing T-cell and NK-cell neoplasms, often superseding precise cell of origin.
• Extranodal T/NK cell lymphomas encompass diverse entities with varying clinical behaviors and associations.
• Understanding these lymphomas is vital for accurate diagnosis and management, especially in immunocompromised patients.