title: Collecting duct carcinoma of the kidney: CT and pathologic correlation.
abstract: OBJECTIVE
  We characterized CT findings of collecting duct carcinoma of the kidney and correlated these with the histopathologic findings.
  
  
  METHODS
  CT scans of 18 patients with pathologically proven collecting duct carcinoma of the kidney were retrospectively reviewed. We analyzed CT findings of collecting duct carcinoma and also correlated CT findings with the histopathologic findings.
  
  
  RESULTS
  The mean size of the tumors was 6.9 cm and all cases were solid. Seventeen (94%) tumors had a medullary location. Nine (69%) and 11 (85%) cases showed weak and heterogeneous enhancement, respectively. A cystic component (50%) was frequently seen within the tumors. Lymphadenopathy and metastasis were noted in 10 (56%) and 6 (33%) cases, respectively. Perinephric stranding and vascular invasion were present in 10 (56%) and 5 (28%) cases, respectively. In 17 (94%) of the 18 cases, involvement of the renal sinus was present. Infiltrative growth (67%) and preservation of the renal contour (61%) were more common than expansile growth (33%) and exophytic configuration (39%), respectively. These CT features were well correlated with the histopathologic findings.
  
  
  CONCLUSIONS
  Medullary location, weak and heterogeneous enhancement, involvement of the renal sinus, infiltrative growth, preserved renal contour, and a cystic component are CT findings frequently seen in patients with collecting duct carcinoma of the kidney. CT findings are nevertheless nonspecific and do not allow collecting duct carcinoma to be easily differentiated from the other subtypes of renal cell carcinoma. However, when CT demonstrates a renal tumor with these findings, collecting duct carcinoma can be considered in the differential diagnosis.
authors.affiliation: Department of Diagnostic Radiology, Dong-A University College of Medicine, 1, 3-Ga, Dongdaesin-Dong, Seo-Ku, Busan, Republic of Korea. cerub@chollian.net
authors.forename: Seong Kuk
authors.initials: SK
authors.lastname: Yoon
authors.forename: Kyung Jin
authors.initials: KJ
authors.lastname: Nam
authors.forename: Seo-Hee
authors.initials: SH
authors.lastname: Rha
authors.forename: Jeong Kon
authors.initials: JK
authors.lastname: Kim
authors.forename: Kyoung-Sik
authors.initials: KS
authors.lastname: Cho
authors.forename: Bohyun
authors.initials: B
authors.lastname: Kim
authors.forename: Kie Hwan
authors.initials: KH
authors.lastname: Kim
authors.forename: Kyung-Ah
authors.initials: KA
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D006801:Humans; D007679:Kidney Medulla; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D008206:Lymphatic Diseases / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D012082:Renal Veins / Q000473:pathology; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed