Role of fine-needle aspiration biopsy in the assessment of sacrococcygeal masses

While fine-needle aspiration (FNA) allows the diagnosis of deep masses, it does not always permit histologic classification. In the case of sites such as the sacrococcygeal region, in which a large number of benign or malignant, epithelial or connective, primary or secondary tumors may arise, it is necessary to choose between conservative treatment and radical surgery. This means that preoperative diagnosis must be as certain as possible. In order to increase the diagnostic accuracy of the method, when even immunohistochemistry is of no aid, it is useful to examine the histologic architecture of the specimen by preparing cell blocks from the aspirates. We report the comparative findings from the examination of the histologic architecture of tissue fragments embedded in methacrylate prepared from the aspirates of four cases of tumors: two chordomas, one metastasis of renal clear-cell carcinoma, and one of mucus-secreting carcinoma, all of them arising in the sacrococcygeal region.