Computed tomography-guided fine-needle aspiration of retroperitoneal lymph nodes in gynecologic oncology. Computed tomography-guided fine-needle aspiration was performed on 30 retroperitoneal lymph nodes in 29 patients with gynecologic cancer. There were no serious complications. Review of the cytologic material demonstrated malignant cells in 83% of the aspirates. Because the predictive value of a positive aspirate approaches 100%, therapy for metastatic disease can be initiated in these patients with the need for an open biopsy. Among five aspirates in which malignant cells were not seen, the cellularity of the specimen appeared to be the critical factor determining the predictive value of the aspirate. Whereas neither of two patients with negative aspirates of adequate cellularity has developed recurrent disease, two of three patients with hypocellular negative aspirates have. Because a hypocellular negative aspirate from a retroperitoneal lymph node may not be a true reflection of disease status, either repeat aspiration or open biopsy is advisable. 