title: Sensitivity of Tru-cut and fine needle aspiration biopsies of liver and kidney for diagnosis of feline infectious peritonitis.
abstract: BACKGROUND
  The detection of typical lesions and feline coronavirus (FCoV) antigen in tissues is the only conclusive method for making a diagnosis of feline infectious peritonitis (FIP). A positive result using Tru-cut biopsy (TCB) and fine-needle aspiration biopsy (FNAB) has high diagnostic specificity, but information about the capacity of these techniques to correctly identify cats with FIP lesions is not available.
  
  
  OBJECTIVE
  The diagnostic sensitivity of TCB and FNAB for detecting liver and kidney histologic lesions caused by FIP was evaluated.
  
  
  METHODS
  TCB and FNAB specimens collected mainly at necropsy from 25 cats with FIP were analyzed. Diagnostic sensitivity was calculated on the basis of the number of false-negative and true-positive specimens, compared with the number of organs bearing histologic lesions of FIP.
  
  
  RESULTS
  Diagnostic sensitivity was higher for hepatic TCB (64%) and FNAB (82%) than for renal (39% and 42%, respectively) procedures. A high percentage of renal cytologic and TCB specimens were inadequate. Combined analysis of TCB and FNAB specimens collected from the same organ increased the diagnostic sensitivity for liver (86%) and kidney (48%). The sensitivity of immunohistochemical/cytochemical analysis was low (11-38% depending on the technique), probably due to variable distribution of feline coronavirus in the lesions.
  
  
  CONCLUSIONS
  Biopsy of liver and kidney can correctly identify FIP lesions. However, false-negative results or inadequate samples occur with moderate frequency, especially for immunochemical analysis. Diagnostic sensitivity may be increased when both TCB and FNAB specimens from the same organ are examined.
authors.affiliation: Dipartimento di Patologia Animale Igiene e Sanitá Pubblica Veterinaria, Milano, Italy. alessia.giordano@unimi.it
authors.forename: Alessia
authors.initials: A
authors.lastname: Giordano
authors.forename: Saverio
authors.initials: S
authors.lastname: Paltrinieri
authors.forename: Walter
authors.initials: W
authors.lastname: Bertazzolo
authors.forename: Emanuela
authors.initials: E
authors.lastname: Milesi
authors.forename: Margherita
authors.initials: M
authors.lastname: Parodi
mesh_terms: D000818:Animals; D044963:Biopsy, Fine-Needle / Q000662:veterinary*; D001707:Biopsy, Needle / Q000379:methods / Q000662:veterinary*; D002415:Cats; D005188:False Negative Reactions; D016766:Feline Infectious Peritonitis / Q000175:diagnosis* / Q000473:pathology*; D005260:Female; D007150:Immunohistochemistry / Q000379:methods / Q000662:veterinary; D007668:Kidney / Q000473:pathology*; D008099:Liver / Q000473:pathology*; D008297:Male; D011336:Probability; D012680:Sensitivity and Specificity