Enhanced detection of lymphovascular invasion in small rectal neuroendocrine tumors using D2‐40 and Elastica van Gieson immunohistochemical analysis oleh Yoshiyasu Kitagawa, Dai Ikebe, Taro Hara, Kazuki Kato, Teisuke Komatsu, Fukuo Kondo, Ryousaku Azemoto, Fumitake Komoda, Taketsugu Tanaka, Hirofumi Saito, Makiko Itami, Taketo Yamaguchi, Takuto Suzuki