Comparison of diagnostic results obtained by fine needle aspiration cytology and tru-cut or open biopsies.

In seven cases fine needle aspiration (FNA) cytology provided a diagnosis of neoplasm when the Tru-Cut (TC) tissue biopsies (four cases) and open biopsies (three cases) were negative. The specimens consisted of two breast carcinomas, two metastatic neoplasms in the liver, one metastatic melanoma in inguinal lymph nodes, a retroperitoneal mass and a pelvic mass. In the two cases of mammary carcinoma, TC biopsies were negative and FNAs were diagnostic of carcinoma. TC biopsies in the two cases of questionable hepatic metastasis were negative, but FNAs demonstrated a malignant neoplasm. Open biopsy of a retroperitoneal mass failed to diagnose a neoplasm however, subsequent ultrasound-directed FNA demonstrated a neoplasm, possibly seminoma. FNA cytology of inguinal lymph nodes in one case was diagnostic of melanoma; open biopsy showed no neoplasm. Because of the FNA diagnosis, additional sections were made and the presence of melanoma was confirmed. This series demonstrates that FNA cytology should be considered the initial diagnostic procedure more often.