Image-directed percutaneous biopsy. A comparison of cytologic and histologic findings.
BACKGROUND: Image-directed biopsies may be collected as histologic or cytologic specimens. METHODS: In 34 patients, the results of aspiration cytologic examination were compared prospectively with core tissue biopsy findings obtained and diagnosed independently using the same image-guided procedure. RESULTS: Cytologic examination disclosed 22 patients with positive or suspicious findings of malignancy; there was one false-suspicious result. Seventeen patients with such results were discovered by examining the core biopsy specimens. Cytologic findings also were more definitive in diagnosing malignancy. Those in whom an immediate interpretation could be done were more likely to have adequate cytologic specimens (88%) than those without (62%). One to five passes were done, but all 21 patients with definitive findings of either benign or malignant by cytologic examination underwent three or fewer passes. The three patients with positive biopsy results, but less definitive cytologic findings, all underwent only one cytologic pass. CONCLUSIONS: Therefore, it was concluded that cytologic examination is more sensitive and definitive than biopsy in diagnosing lesions using image guidance. Immediate interpretation and/or multiple passes increase the diagnostic yield. However, more than three aspiration cytologic passes appear to yield diminishing returns.