Abstract: Wu Wei, Fan Ruiqiang, Luo Jiasheng, Qin Xiaomin. Department of Dermatology, Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou 510120, China Corresponding author: Wu Wei, Email: wuwei1350187@126.com 【Abstract】 A 47-year-old man presented with recurrent oral ulcerations for more than 1 year and generalized vesicles for 9 months. Physical examination revealed multiple oral ulcers, patchy labial erosions with yellow or dark brown crusts, maceration and blanching of the angle of mouth resulting in difficulty in mouth opening. Cinnamomeous crusts were seen on the nasal limen, palpebral margin and coronary sulcus of penis, with pale red macules after decrustation. Diffuse erythematous patches and bullae were present on the trunk and extremities. The walls of bullae tightly clung to the skin, and some bullae were ruptured, leaving an erythematous and moist surface and giving an erythema multiforme-like appearance; some bullae were turbid and covered with adherent drug-containing white crusts or black crusts. Nikolsky′s sign was negative. Shrinking, edematous dark-red patches were seen in periungual regions of all the fingers and toes. Histologic biopsy and direct immunofluorescence examination of bullous lesions confirmed a diagnosis of paraneoplastic pemphigus （PNP）. Histopathological and immunohistochemical findings from the mediastinal tumor were consistent with Castleman disease （hyaline-vascular type） with proliferation of follicular dendritic cells. Laboratory examination revealed a decrease in serum complement C3 and the presence of antinuclear, anti-nucleosome and anti-dsDNA antibodies. The final diagnosis included Castleman disease, PNP and systemic lupus erythematosus. After 2 months of treatment with low-dose prednisone and azathioprine, skin lesions completely regressed. Then, the dose of prednisone and azathioprine was tapered. Six months later, the patient himself suddenly withdrew prednisone and azathioprine, and began to take traditional Chinese medicine; thereafter, the lesions developed into toxic epidermal necrolysis （TEN）, and the patient died finally. This case demonstrates that immunosuppressive therapy should be maintained for a long period of time in patients with Castleman disease after tumor removal, otherwise, skin lesions may recur or get worse.

Key words: Giant lymph node hyperplasia, Paraneoplastic pemphigus, Lupus erythematosus, systemic