Merkel cell carcinoma associated with chronic treatment with hydroxyurea: a case report

Merkel cell carcinoma is a rare neuroendocrine tumour of the skin, that shows a quickly and aggressive behaviour and carries a poor prognosis. Surgery is the standard primary treatment modality, while radiotherapy plays a role in postoperative treatment. Radiotherapy is also an alternative to unresectable lesions or patients who are unfit to surgery. Here we report a 90-year-old male with polycythemia vera that was chronically treated with hydroxyurea for about 30 years. The patient presented a purple and exophytic frontal scalp lesion, which had recurred after primary wide excision. This recurrence had been considered inoperable and the patient was treated with external beam radiotherapy to the lesion and locoregional lymph nodes, showing a complete clinical response after 12 weeks. However, disease progressed rapidly, and the patient died from distant metastasis 4 months later. This report is the second described case in literature of Merkel cell carcinoma as complication of chronic hydroxyurea and highlights the need for these patients to undergo regular and close dermatological evaluation.