Diagnosis of soft tissue tumors by fine-needle aspiration with combined cytopathology and ancillary techniques.

The diagnosis of mesenchymal neoplasm by fine-needle aspiration biopsy (FNAB) has presented a diagnostic challenge. Most reports claim an accuracy approaching 95%, but while they distinguish benign and malignant lesions, the most problematic group, the intermediary malignant group, is omitted. The purpose of this study was to determine whether rapid cytologic diagnosis of soft-tissue tumors could guide surgeons in therapeutic decisions without the need for a tissue biopsy. Ninety-four FNA cytologic specimens were examined by the National Soft Tissue Consortium of Hungary and compared with the corresponding histology. Ordinary lipomas were excluded. Morphologic evaluation was supplemented by ancillary techniques such as fluorescence in situ hybridization (FISH), DNA cytometry, and immunocytochemistry. From a practical clinicopathological point of view, the cases were grouped in the following categories: 1) tumors with definitive diagnosis: a) high-grade malignant neoplasms (high-grade sarcomas, metastatic carcinomas, lymphoma), b) tumors with precise histogenetic origin by cytogenetics, c) benign tumors; 2) tumors of questionable nature. In the first group there were 74 tumors: 22 high-grade sarcomas, six metastatic carcinomas, one malignant lymphoma, 16 malignant tumors in which the precise histogenetic origin could be established by cytogenetic studies, and 29 benign soft-tissue tumors other than lipomas. In the second group there were 20 tumors comprising benign and malignant soft tissue tumors of low grade, wherein the precise nature of the neoplasm could not be established with confidence on cytologic study, even using ancillary techniques. FNAB of soft-tissue tumors combined with ancillary techniques should be considered a viable diagnostic technique for therapeutic protocols. Although the second group is fairly large, we have reliable, well-characterized categories which provide great freedom for preoperative and surgical treatment, thus providing the best chance for healing. Copyright 2002 Wiley-Liss, Inc.