Purpose: Merkel cell carcinoma (MCC) is a rare aggressive neuroendocrine tumor of the skin mainly found in elderly white patients. Due to its poor prognosis with distant metastases in up to 33% and local recurrence in 25-33% and a 5 year disease-specific survival of 64% (1-2) its early diagnosis and appropriate treatment is mandatory.
Methods: The study is an exceptional clinical case of a patient with a large inoperable MCC unable to be treated according to treatment guidelines due to her old age. We review the literature addressing treatment options.
Results: The patient was treated with palliative definitive radiotherapy to her large MCC of the left lower leg. She showed a rapid clinical response to four palliative radiation doses of 7 Gy each, necrosis of tumor mass and persistent clearing at a follow-up of 32 weeks. Our patient was very unusual in terms of her extensive MCC and her rapid and complete response to palliative radiotherapy lasting for 6 months at present.
Conclusions: As MCC is an aggressive tumor, best survival is achieved with early diagnosis in a localized stage and prompt adequate surgery and further stage-adjusted treatment. Thus, the differential diagnosis of MCC should not be dismissed in a reddish nodule on the leg, and every excision should be submitted to pathology. In accordance with the literature we demonstrate here that definitive radiotherapy is an effective treatment option for inoperable MCC, which in this individual patient produced necrosis of the extensive tumor mass after only four palliative doses.