Pachyderma in Primary Cutaneous NK and T-Cell Lymphoma and Leukemia Cutis

BACKGROUND: Pachyderma is defined as severely thickened skin with deep folds and is occasionally observed with primary cutaneous NK and T-cell lymphoma (pCNKTCL), primary cutaneous B-cell lymphoma (pCBCL), and leukemia cutis (LC). AIM: To describe the clinical, histological, and therapeutic particularities of a series of pCNKTCL, pCBCL, and LC patients with pachyderma. RESULTS: In a series of pCNKTCL (n = 70), pCBCL (n = 12), and LC (n = 2) patients followed up during 9 years, 6 cases of pachyderma were observed. Pachyderma occurred on the arms (n = 2), thighs (n = 1), forehead (n = 1), and face (n = 2). The mean age of the patients was 69 years (51–82). The stages were erythrodermic (T4) mycosis fungoides (MF) (n = 1), folliculotropic MF (FMF) (n = 2), classic (T2) MF (n = 2), and chronic myeloid leukemia (n = 1). The erythrodermic MF patient with acute pachyderma on the right arm responded rapidly to oral steroids. The other cases were indolent, appeared progressively, and were highly treatment resistant. Histology revealed dense dermal neoplastic infiltration. The immunohistological profile of the pachydermic lesions was similar to common MF and LC. CONCLUSION: Pachyderma is an atypical manifestation of MF and LC and may occur on the face (FMF) or the extremities (MF). The rapidly appearing pachyderma may be transitory and responds readily to oral steroids.