Sacral and presacral lesions: cytopathologic analysis and clinical correlates.

Although percutaneous biopsies of the spine at thoracolumbar levels have proven value, the benefit in the sacrococcygeal region has not been presented thoroughly in the literature. This region has unique anatomic and oncologic properties. The cytopathologic files at The Johns Hopkins Hospital over a 20-year-period were searched. Imaging studies and medical records were also reviewed. Ninety-one cases of sacral/presacral FNA were identified. There were 46 males and 45 females; 62% had a prior history of malignancy. The most common presentation was lower back pain (44%). Imaging revealed lytic and/or soft tissue lesions masses from 1 to 12 cm (mean = 5.0 cm). Of the 71 (78%) diagnostic cases, 19 (27%) were nonneoplastic, 2 (3%) were suspicious for neoplasm, while 50 (70%) cases were neoplastic. Of the nonneoplastic cases, 10 (53%) showed nonspecific inflammation. Two (4%) of the 50 neoplastic lesions were benign tumors (schwannoma and neurofibroma), and of the malignant cases, 11 (23%) were primary, and 37 (77%) were metastatic/secondary. The most common primary malignant tumor was chordoma (four cases, 36%). Of the 37 secondary tumors, the most common were colorectal carcinoma (8, 22%) and plasmacytic tumors (5/9, 56%). The overall accuracy, sensitivity and specificity of FNA were 96, 95, and 100%, respectively. Sacral and presacral lesions represent rare targets for FNA. Benign tumors are rare (2%). Most cancers are metastatic (41%), with colorectum being the most common primary site (9%). Primary malignancies are uncommon (14%), with chordomas being the most frequent of these entities (4%).