Complete remission of Merkel cell carcinoma of the scalp with local and regional metastases after topical treatment with dinitrochlorbenzol.

Merkel cell carcinoma (MCC) is a highly aggressive tumor with a high percentage of recurrence, metastatic spread, and mortality. Treatment of metastasized MCC is not standardized and prognosis of metastasized MCC is often poor. Current protocols recommend surgery, adjuvant radiation therapy, and often lymph node dissection to prevent recurrences. A few sporadic reports of spontaneous regression of MCC suggest a so far not yet characterized role and potential of the immune system in controlling this tumor. We describe a 69-year-old man with extended inoperable MCC of the scalp including multiple local and regional metastases who responded with complete remission to 4 weekly treatments of topically applied immune-modulating dinitrochlorbenzol. Together with subsequent irradiation, remission has now lasted for more than 1 year.