title: Small renal cell carcinoma: MRI with pathologic correlation.
abstract: The MRI features of small renal cell carcinomas (RCCs) were retrospectively reviewed and correlated with histology in 24 patients. MRI features on both T1- and T2-weighted images were classified into hypointensity, isointensity, and hyperintensity. Each tumor was pathologically classified into four types: alveolar, papillary, tubular, and cystic. These findings were correlated with MR signal intensities. Alveolar tumors showed hypointensity to isointensity on T1-weighted image and isointensity to hyperintensity on T2-weighted image. In contrast, all papillary tumors showed hypointensity on T2-weighted image. Four of six tumors with hypointensity on T2-weighted image were caused by hemosiderin deposition, hemorrhage, and necrosis. However, there were two papillary RCCs that showed hypointensity on T2-weighted image despite no hemosiderin deposition and no hemorrhage. We conclude that papillary RCC is associated with T2-hypointense appearance as well as hemosiderin deposition, hemorrhage, and necrosis.
authors.affiliation: Department of Diagnostic Radiology, Keio University School of Medicine, Tokyo, Japan. shinmoto@ga2.so-net.or.jp
authors.forename: H
authors.initials: H
authors.lastname: Shinmoto
authors.forename: Y
authors.initials: Y
authors.lastname: Yuasa
authors.forename: A
authors.initials: A
authors.lastname: Tanimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Narimatsu
authors.forename: M
authors.initials: M
authors.lastname: Jinzaki
authors.forename: K
authors.initials: K
authors.lastname: Hiramatsu
authors.forename: M
authors.initials: M
authors.lastname: Mukai
mesh_terms: D000328:Adult; D000368:Aged; D002292:Carcinoma, Renal Cell / Q000145:classification / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006801:Humans; D007668:Kidney / Q000473:pathology; D007680:Kidney Neoplasms / Q000145:classification / Q000175:diagnosis* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D012189:Retrospective Studies; D012680:Sensitivity and Specificity