title: Rectal villous tumours: MR features and correlation with TRUS in the preoperative evaluation.
abstract: OBJECTIVE
  The aim of this study was to assess the clinical relevance of MR and transrectal ultrasonography (TRUS) imaging of rectal villous tumours to elucidate the correlation between imaging results and specific histopathological tumour features, such as tumour size (T) and lymph node involvement (N), in order to establish the better technique for the pre-surgical patient evaluation.
  
  
  METHODS
  23 cases of villous tumours of the rectum were studied with phased-array MR and TRUS. All patients underwent either surgical or endoscopic treatment. Final diagnosis was based on histopathological results. In particular, the following features were characterized by the imaging techniques mentioned above: lesion site, distance between lesion and ano-rectal junction, size, morphology and contrast enhancement of lesions, fluid layer around the lesion, alterations of the deep layers of the rectal wall, sphincter infiltration, presence or absence of mesorectal, iliac and obturatory lymphnode involvement.
  
  
  RESULTS
  Histology established muscular involvement in 7 cases (T2), perirectal fat infiltration in 1 case (T3); in the remaining 15 cases, staging was Tis-T1. In 17/23 cases (73.9%) the lesions were correctly staged with both imaging techniques, whereas in 5/23 cases (21.7%) the lesions were overstaged. No cases were understaged. TRUS concorded with histological exams in 17/23 cases (73.9%). 5/23 cases (21.7%) were overstaged and 1/23 (4%) was understaged. MR and TRUS were in accordance in 20/23 cases (86.9%).
  
  
  CONCLUSIONS
  Considering the frequent degeneration of villous tumours, correct preoperative identification and precise evaluation of these lesions, such as the detection of rectal wall invasion, is essential in deciding optimal treatment strategy. MRI and TRUS allow the identification of specific features of villous tumours and of malignant degeneration, allowing for a correct local disease staging.
authors.affiliation: Radiology Section of Emergency Department, Azienda Policlinico Umberto I Rome, via Alberico Albricci 28, 00194 Rome, Italy. marinadevargasm@hotmail.com
authors.forename: Marina
authors.initials: M
authors.lastname: De Vargas Macciucca
authors.forename: Alessandra
authors.initials: A
authors.lastname: Casale
authors.forename: Lucia
authors.initials: L
authors.lastname: Manganaro
authors.forename: Irene
authors.initials: I
authors.lastname: Floriani
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Fiore
authors.forename: Luca
authors.initials: L
authors.lastname: Marchetti
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Panzironi
mesh_terms: D018253:Adenoma, Villous / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012004:Rectal Neoplasms / Q000175:diagnosis*; D012007:Rectum / Q000000981:diagnostic imaging* / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D014463:Ultrasonography / Q000379:methods*