Figure 1: A 51-year-old Taiwanese man with invasive thymoma for 5 years developing GVHD-like erythroderma. (a) Chest X-ray showed pleural effusion and right hilum enlargement. (b) Computed tomography showed an anterior mediastinal tumor next to the ascending aorta with calcification (yellow arrow). (c-e) Generalized confluent scaly erythematous papules and plaques on his trunk and limbs including soles, involving more than 90% of the body surface area. Some lesions showed an annular pattern, and some had purpuric centers. Histopathological findings of the skin biopsy showed (f) confluent parakeratosis, focal vacuolar interface change with scattered necrotic keratinocytes mostly in the upper layer of epidermis with adjacent one or more lymphocytes (black arrows), and mild superficial perivascular inflammatory infiltrates (H and E, ×400). (g) CD4+ T-cells infiltration mostly in the papillary dermis (CD4, ×200); and (h) epidermal infiltration of CD8+ T-cells (CD8, ×200).