Serial pseudoprogression of metastatic malignant melanoma in a patient treated with nivolumab: a case report oleh Yukinori Ozaki, Junichi Shindoh, Yuji Miura, Hiromichi Nakajima, Ryosuke Oki, Miyuki Uchiyama, Jun Masuda, Keiichi Kinowaki, Chihiro Kondoh, Yuko Tanabe, Tsuyoshi Tanaka, Shusuke Haruta, Masaki Ueno, Shigehisa Kitano, Takeshi Fujii, Harushi Udagawa, Toshimi Takano