Pediatric lymphomatoid papulosis: a broad clinicopathologic spectrum including rare variants in a single-center case series

Abstract

Background Lymphomatoid papulosis (LyP) is a rare CD30-positive cutaneous T-cell lymphoproliferative disorder, extremely uncommon in children and adolescents. Despite its indolent course, LyP may mimic malignant lymphomas clinically and histopathologically, making diagnosis challenging in pediatric patients. Objectives To characterize the clinical, histopathologic, immunophenotypic and molecular features of pediatric LyP and to describe treatment approaches and clinical outcomes. Methods We performed a retrospective observational study of pediatric patients with clinicopathologically confirmed LyP evaluated at our tertiary referral center between 2004 and 2025. Demographic, clinical, histopathologic, immunophenotypic, molecular, treatment and follow-up data were collected. Results Nine patients were included (8 males, 1 female), with a median age at diagnosis of 11 years (range 2–18). Lesions predominantly involved the limbs (9/9, 100%), followed by the trunk (5/9, 56%) and hands (4/9, 44%). Ulceration or necrotic evolution occurred in 6/9 patients (67%). Type A was the most common histologic subtype (5/9, 56%), followed by single cases of types B, D, E and one overlap A–C case. CD30 expression was observed in all patients. T-cell receptor clonality was identified in 4/5 tested cases. Management was mainly conservative, consisting of topical corticosteroids and phototherapy (nbUVB or PUVA). Methotrexate was used in one patient. At the last follow-up, all patients were free of active LyP lesions, and no associated hematologic malignancy was documented. Conclusions Pediatric LyP shows heterogeneous clinicopathologic features with overall favorable outcomes. However, long-term follow-up remains warranted due to the lifelong risk of associated lymphoproliferative disorders.