RESUMO
Purpose: To analyze the diagnostic yield for each specimen obtained at 16-gauge CT - guided renal biopsy and compare these finding with mass, procedural, and specimen characteristics that could affect yield. Patients, Materials and Forty nine consecutive biopsies of renal masses were performed by using a 16-gauge needle. Each specimen was graded for whether it was non-fragmented or fragmented and for whether it sank or floated, and each pass was graded for whether or not the needle passed through the lesion. Each specimen was mounted on a seqarate slide. A pathologist who was unaware of the final diagnoses reviewed the slides in random order. A diagnosis was determined for each specimen whenever possible and diagnostic yield was calculated as a function of number or passes. thirty-nine [79.6%] lesions were malignant and 10 [20.4%] were benign. Cells indicating the final diagnosis were contained in 164 [75%] of 218 specimens. Cells indicating the diagnosis were contauned in the first specimen in 38 [77.5%] lesions, in the second specimen in 45 [92%], in the third specimen in 47 [96%], and in the fourth specimen in 49 [100%]. Of the 39 malignancies, 36 [93%] were diagnosed with cells contained in the first or second specimen, one cancer [renal cell carcinoma in situ] was diagnosed with sells contained in the forth specimen. Specimens that were non-fragmented [P<. 001] and sank [P<.001] showed correlation with being diagnostic, but needle visualization within the lesion did not. A minimum of four specimens, preferably those that are non-fragmented and that sink, should be obtained with 14-gauge CT-guided renal biopsy