title: Hepatocellular carcinoma with a "nodule-in-nodule" appearance reflecting an unusual dilated pseudoglandular structure.
abstract: We present a case of hepatocellular carcinoma (HCC), showing an atypical "nodule-in-nodule" appearance on ultrasonogram (US). In general, a "nodule-in-nodule" appearance is found as a hyperechoic tumor containing a hypoechoic nodule. In the present case, however, there was a hyperechoic subnodule in the center of the tumor, which was surrounded by a hypoechoic tumor area. Histologically, the subnodule consisted of moderately differentiated HCC with a markedly dilated pseudoglandular structure, and the outer tumor consisted of well-differentiated HCC with a thin-trabecular pattern. It should be noted that there is a rare HCC with dilated pseudoglandular structure showing the inversed "nodule-in-nodule" appearance.
authors.affiliation: Division of Gastroenterology, Department of Medicine, Kurume University School of Medicine, Karume, Japan. ishida_yuusuke@kurume-u.ac.jp
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Ishida
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nagamatsu
authors.forename: Hironori
authors.initials: H
authors.lastname: Koga
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yoshida
authors.forename: Masamichi
authors.initials: M
authors.lastname: Kojiro
authors.forename: Michio
authors.initials: M
authors.lastname: Sata
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D014463:Ultrasonography