Merkel cell tumour is a rare malignant cutaneous neoplasm of neuroendocrine origin. It mainly affects women over 50, is generally located in photo-exposed areas, is normally asymptomatic and of rapid growth. It has a high percentage of recurrences and metastasis, with the most frequent sites of dissemination being the skin, followed by the regional lymph nodes. Its treatment is still controversial. We report a clinical case of a 76-year-old woman with erythematous nodule in the right forearm that was not responding to treatment. The final diagnosis was a Merkel tumour and after the treatment it shows good progress.