Double Primary Cancers of Earlobe Merkel Cell Carcinoma and Lung Adenocarcinoma

Merkel cell carcinoma (MCC) is an aggressive neuroendocrine carcinoma with a high rate of metastasis. MCC is rarely suspected during clinical examination, thus requiring biopsy to establish a pathologic diagnosis. In addition, MCC sometimes occurs in double primary cancers. Although there have been reviews on double primary cancers, only a few cases involving MCC have been described. Herein, we report a case of a 54-year-old female patient who presented to our clinic with a diagnosis of earlobe MCC following an excisional biopsy performed by another clinic. Further evaluation, including chest imaging, revealed a mass in the lung. The patient underwent a wide excision of the right earlobe, and video-assisted thoracic surgery on the lung. Pathology confirmed MCC in the right earlobe and adenocarcinoma in the lung. The patient underwent postoperative adjuvant chemotherapy followed by radiotherapy. Up to this point, 3 years after the surgery, there has been no evidence of recurrence.