Rosai-Dorfman disease (RDD) is a rare idiopathic benign disease, self-limited non-Langerhans cell histiocytosis, most frequently presented as a massive bilateral and painless lymphadenopathy, associated with fever and weight loss. Extranodal manifestations of RDD represents a true diagnosis challenge for clinicians and surgical pathologists. A 64-year-old female, known with arterial hypertension and type 2 diabetes, presented to our Surgery Clinic for a left arm painless cutaneous tumour, having its onset one year before, and rapidly enlarged in the last two months. Physical examination revealed a firm and elastic cutaneous nodular lesion of 4 x 2 cm in size, prominent to the skin, with central ulceration area of 10 x 5 mm, located on the posterior side of the left arm. Surgery was performed, with lymphoma as a differential diagnosis at intraoperative extemporaneous examination. The RDD disease diagnosis was considered at histopathological analysis and confirmed by immunohistochemistry. Herein, we describe a rare case of purely cutaneous RDD presenting as unique cutaneous ulcerative nodular lesion, surgical treated only, and without local relapse after one-year follow-up.