A comparison of fine needle aspiration cytology and tru-cut tissue biopsy in the diagnosis of acute renal allograft rejection.

Simultaneous Tru-cut biopsies and fine needle aspirations (FNAs) performed over a 2-year period on patients following renal transplantation were assessed by independent pathologists. When there was histological evidence of rejection, FNAs also demonstrated cellular features of rejection in 83% of cases, and this increased to 92% with repeated sampling. The presence of monocytes and histiocytes in FNAs correlated with vascular features of rejection on biopsy and failure to reverse the rejection process with steroids.