Cutaneous Follicle Center Lymphoma : Differential

Comments:
Primary cutaneous follicle center lymphoma (PCFCL) vs Primary Cutaneous Marginal Zone Lymphoma (PCMZL) - Differential Diagnosis (continued).

Features favoring PCMZL:

• lesions on trunk and extremities in middle aged men; often multifocal
• follicles appear reactive or may be colonized by neoplastic centrocytes
• infiltrate consists of centrocytes, monocytoid B-cells, lymphoplasmacytoid & plasma cells
• few centroblasts and immunoblasts
• neoplastic lymphocytes are positive for CD20, CD79a, PAX5, CD43 (50%) and BCL2
• Negative for CD5, CD10, BCL6, and cyclin D1
• presence of light chain-restricted monotypic lymphoplasmacytoid and plasma cells