Cutaneous Plasmablastic Lymphoma: Comparative Analysis of Primary and Secondary Skin Involvement

Summary: Background: Cutaneous plasmablastic lymphoma (PBL) is an aggressive neoplasm presenting as rapidly growing skin nodules. Skin involvement occurs in ~5% of PBL cases, and no specific classification exists for primary cutaneous PBL in the WHO. This study analyzes 44 cases, the largest known review, to enhance understanding of this entity. Methods: A literature review and institutional archives identified 44 cutaneous PBL cases. These were categorized as primary (no extracutaneous involvement; n=27) or secondary (with extracutaneous disease; n=17). Clinicopathologic and immunohistochemical data were analyzed. Statistical analyses, including survival analysis, were conducted using IBM SPSS. Results: Significant differences were observed in age (p= 0.005) and light chain restriction (p= 0.015). Leg involvement was more frequent in the primary group (67% vs. 33%), with a trend toward significance (p= 0.064). Cox regression, adjusted for confounders, showed higher mortality in secondary cases (p= 0.028) and reduced mortality in EBV-positive tumors within the primary group (p= 0.035). Conclusions: This study provides a comprehensive clinicopathologic characterization of cutaneous PBL. Secondary skin involvement predicts a poor outcome, while EBV positivity is associated with better survival in primary cases. These findings lay a solid foundation for future research and the improved management of this rare lymphoma.