Fine needle aspiration cytology vs. needle core biopsy of soft tissue tumors. A comparison.

Fine needle aspiration (FNA) cytology is an effective modality in the diagnosis of soft tissue lesions. Previous studies compared FNA with surgical biopsies and reported high sensitivity and specificity rates. No study has evaluated the diagnostic yield of FNA to that of needle core biopsies (NCBs). One hundred seventeen FNAs were performed by our clinical staff for soft tissue lesions (1980-1992). The FNAs were divided into three categories: diagnostic 53 (37 sarcoma, 16 benign); unsatisfactory, 44; normal/inflammatory cells present, 20. Of these, 59 had concomitant NCBs: 37 on patients with sarcoma on FNA, 22 on unsatisfactory FNA and none on those with normal/inflammatory cells (followed clinically). There was 100% correlation between FNA and NCB when sarcoma was diagnosed. In 7 of these cases, the NCB further specified the type of sarcoma. No NCBs were employed to confirm the diagnosis of benign tumor on FNA; excisional biopsies showed a total correlation. The 22 NCBs for unsatisfactory FNA yielded 15 sarcomas, 2 fibromatosis and 5 benign lesions. Seventeen patients with unsatisfactory FNA had surgical biopsies (3 sarcoma, 14 benign), and 5 were lost to follow-up. In our experience, diagnostic FNA gave a yield identical to that of NCB, and the latter did not contribute to patient management. Core biopsies may have the advantage of subtyping selected sarcomas diagnosed by FNA. Unsatisfactory FNA should be evaluated further by a repeat aspirate or NCB. Performance of FNA by cytopathologists can reduce the number of unsatisfactory specimens and allow repeat aspiration. In our study most of the unsatisfactory FNAs were from retroperitoneal and pelvic lesions, were performed under radiographic guidance and could have been minimized by immediate cytologic assessment. Many of these lesions, however, may be as readily accessible via NCB as they are via FNA. Utilization of each of these modalities and of their full benefits ultimately depends on the proper clinical setting and the experience of the clinician and pathologist.