Age- and Sex-Related Differences in Primary Cutaneous Lymphoma.

Few studies have directly compared primary cutaneous lymphomas (PCLs) in pediatric and adult populations. In this retrospective observational study, we evaluated the clinical characteristics, subtypes, treatment patterns, and outcomes of PCLs in 54 children and 104 adults evaluated at 2 tertiary institutions between January 1, 1999, and December 31, 2019. Statistical analysis was performed using χ2 and Mann-Whitney U tests. Our findings indicated that the time to diagnosis was shorter in children vs adults. Mycosis fungoides (MF) was the most common diagnosis, most often manifesting as erythematous plaques, with frequent lower-extremity involvement. Key differences between groups included a higher frequency of MF in adults, whereas chronic active Epstein-Barr virus (EBV)-associated lymphoproliferative disease occurred exclusively in children; pediatric patients more often presented with hypopigmented lesions, and systemic therapies were used only in children.