・ TAKAHASHI Shin-ichi 3 ) ・ NOMURA Takeshi 1 ) : Eosinophilic ulcer (EU) is a rare self-limiting oral condition, frequently occurring on the tongue and appearing as an ulcer with elevated induration of the surrounding tissue. Consequently, there is risk of misdiagnosis as carcinomatous ulcer. We describe a 30-year-old man with a painful ulcer on the tongue, which reappeared one and a half months after healing. First, a lesion developed on the dorsum of the tongue. The lesion healed without

more »

... e treatment after 1 month. However, two lesions were then observed on the right ventral aspect of the tongue. Histopathological examination of the lesions showed ulceration and inflammatory deterioration with distinct eosinophilic infiltration extending into the deep underlying connective tissue and muscle fibers. Immunohistochemical analysis revealed a large number of CD30-positive large atypical cells among inflammatory cells. As a result, an eosinophilic ulcer was diagnosed. The recurrent lesions also healed without active treatment, similar to the primary lesion. : eosinophilic ulcer (好酸球性潰瘍) ,immunohistochemistry (免疫組織化学) ,CD30-positive lymphoproliferative disorders (CD30 陽性リンパ増殖性疾患) ,differential diagnosis (鑑別疾患) ,recurrence (再燃) 1) 東京歯科大学オーラルメディシン・口腔外科学講座 (主任:野村武史教授) 2) 東京歯科大学市川総合病院臨床検査科病理 (主任:佐々木 文教授) 3) 東京歯科大学市川総合病院皮膚科 (主任:高橋愼一教授) 1)