Importance of Early Detection and Complete Resection of Primary Cutaneous Mucinous Carcinoma with Lymphatic Metastasis: A Case Report and Literature Review.

A 67-year-old man had a tumor on his right cheek. It was resected 15 years earlier but recurred 1 year before his first visit. He had a red papule on his right cheek and subcutaneous induration in the right preauricular area. A right cheek biopsy revealed a mucinous carcinoma. The positron emission tomography-computed tomography showed accumulation only in the right cheek and parotid gland lymph node; therefore, we diagnosed primary cutaneous mucinous carcinoma. Sentinel lymphoscintigraphy showed accumulation of parotid gland and level II lymph node. He underwent extended resection and sentinel-node biopsy. Both lymph nodes were metastatic, requiring the appropriate range of neck dissection. There were no recurrence and metastasis postoperatively. There is no effective treatment when distant metastasis occurs, and the prognosis is poor. Therefore, it is important to prevent metastasis. However, positron emission tomography-computed tomography could not reveal early micrometastases. Therefore, a sentinel-node biopsy can be key to early detection and treatment.