Lymphomatoid papulosis

Abstract

Lymphomatoid papulosis (LyP) is a rare, chronic, relapsing disease characterized by papulonodular or papuloulcerative skin lesions. According to the 2018 WHO-EORTC classification, it belongs to the spectrum of primary cutaneous CD30-positive T-cell lymphoproliferative disorders, with several histological subtypes (A, B, C, D, E, and a variant associated with DUSP22-IRF4 gene rearrangement). Although histologically similar to malignant lymphomas, its clinical course is considered an indolent hematological condition. The papules and nodules tend to regress spontaneously, but ulceration may occur in certain types. In mild cases, local therapy is sufficient, while severe or extensive cases may require systemic immunomodulatory or targeted therapy. Despite its rarity and generally favorable prognosis, the increased risk of secondary hematological malignancies (5–25%) highlights the importance of close follow-up. This article reviews the latest classification, pathomechanism, diagnostic algorithm, and treatment options for LyP based on international and Hungarian literature.