Figure 1: Macroscopic and microscopic findings in the skin of the patient. a, b, c) Newly-occurred nodular erythemas (15-60 mm in diameter) after the mogamulizumab administration. The plaques were erythematous with sharply-defined margins and hyperkeratosis. d) The pathological examination of nodular erythemas (Hematoxylin-Eosin staining ×200) revealed Munro`s micro abscess (blank arrow head), infiltration of lymphocytes in superficial dermis (circled by black arrow heads), and elongation of rete ridges (blank arrow), hyperkeratosis, all of which were compatible with findings in psoriasis vulgaris.