CD30⁺ cutaneous lymphoproliferative disorders with pseudocarcinomatous hyperplasia are associated with a T-helper-17 cytokine profile and infiltrating granulocytes

Background The pathogenetic mechanism of CD30⁺ cutaneous lymphoproliferative disorders (CLPD) associated with pseudocarcinomatous hyperplasia (PCH) and granulocytic inflammation surrounding atypical CD30⁺ lymphocytes remains unclear. Objective We sought to characterize clinical and pathological findings of a cohort of patients with PCH associated with CD30⁺ CLPD and to analyze the cytokine profile of the atypical lymphocytes. Methods We retrospectively reviewed medical records and pathological material of CD30⁺ CLPD with PCH. Immunohistochemistry for T-helper (Th)17 cytokine profile was performed. Results In all, 25 patients with a median age of 52 years were included. The median follow-up was 3.7 years. Histologically, an infiltrating pattern of PCH was observed in 14 cases with a neutrophilic-rich infiltrate (P =.21), and epidermal pattern in 11 cases with eosinophil-rich infiltrate (P =.03). Th17 or Th22 cytokines were detected in tumor cells in 81% cases tested. Tumor cells expressed Th17 transcription factor retinoic acid receptor (ROR)-related orphan receptor gamma-2 in 2 of 7 samples tested and 1 was positive for aryl hydrocarbon receptor. Limitations This is a retrospective study of a small sample. Conclusions PCH in CD30⁺ CLPD is associated with Th17/Th22 cytokine expression in the atypical lymphocytes. Although these lesions commonly regress spontaneously and are associated with an indolent course, some cases develop a generalized process and tumor progression.