Acral malignant melanoma; emphasis on the primary metastasis and the usefulness of preoperative ultrasound for sentinel lymph node metastasis. - Kwon, Mi-ri; Choi, Sang-Hee; Jang, Kee-Taek; Kim, Jung-Han; Mun, Goo-Hyun; Lee, Jeeyun; Lee, Dong-Youn (Scientific Reports, 2019)