A case of refractory Kimura disease with a buccal bulky mass successfully treated with low-dose cyclosporine A: Report and review of the literature

Kimura disease (KD) is a chronic inflammatory disorder that presents as painless lymphadenopathy or subcutaneous masses, most predominantly in the head and neck region. Peripheral eosinophilia and elevated serum IgE levels are the characteristics of the disease. Promoted helper type 2 (Th2) responses are suggested to be the mechanism underlying KD. Although the disease has a benign course, relapse often occurs after the first-line therapy, which includes surgical excision, radiotherapy, and topical steroids. Recently, cyclosporine A (CsA) for the treatment of recurrent KD has been reported. Here, we describe a patient with recurrent KD after surgical and medium-dose steroid therapy who was successfully treated with low-dose (2 mg/kg/d) CsA. We also review the literature related to CsA treatment for KD. A 25-year-old Japanese man with a childhood history of atopic dermatitis presented with a left buccal soft tumor (Fig. 1A). At the age of 11 years, he had been diagnosed as having KD on the basis of biopsy findings for a left buccal tumor. At the age of 16 years, he had undergone surgical excision of the tumor, followed by oral steroid therapy. Although he had remained in remission for 1 year, after discontinuation of the oral steroid, the tumor had again grown in size, to that of a goose egg. He was referred to the otorhinolaryngology department for surgical excision of the tumor again; this time, however, the tumor could not be excised owing to an ambiguous margin between the tumor and the normal tissue that was due to the progression of fibrosis. He was prescribed 50 mg/d (0.7 mg/kg/d) of oral prednisolone (PSL) after the surgical biopsy, followed by tapering by 10% every 4 days. After the dose of PSL was tapered to 30 mg/d, the tumor reduction ceased, and he was subsequently referred to our internal medicine department. The laboratory findings revealed an increased leukocyte count of 15,200/mm3 with hypereosinophilia (eosinophils: 10,792/mm3 [71%]); hemoglobin: 17.4 g/dl; and platelets: 241,000/mm3. C-reactive protein was negative and the erythrocyte sedimentation rate was normal. The urinalysis and kidney function were also normal. He had extremely elevated serum IgE levels (6519 mg/dl) when taking 30 mg/d of oral PSL. Soluble IL-2 receptor was elevated to 952 U/ml and IgG4 was within normal range. In this case, the serum levels of Th2 cytokines such as IL-4, IL-5, and IL-13 were below detection limits. Magnetic resonance imaging revealed a 75 135 145-mm tumor in the left buccal region from the