Objective: To review of the value of fine needle aspiration (FNA) cytology in the diagnosis of soft tissue tumors (STT).
Study design: A review of the literature was coupled with the authors' experience with indications, diagnostic specificity and pitfalls; clinical information; and the final cytology report.
Results: Over the last few years, FNA has come to be considered a valuable tool in the management of STT in that it affords a specificity of > 90%. FNA is of particular value in any subcutaneous lesion > 5 cm, in all pediatric tumors and whenever direct incision biopsy is particularly contraindicated. Material from aspirates can be used to obtain cytologic smears for conventional staining, special pigment identification, histochemical techniques, cell blocks for paraffin embedding and ancillary techniques (immunocytochemistry, electron microscopy, and densitometric and cytogenetic analyses). The cytologic diagnosis, like its histologic counterpart, should be based on a correct evaluation of clinical data (age, localization, size, effect on bone, nerve and vessel involvement), radiologic information, cytologic findings (architectural pattern, cell and stroma characteristics) and results of special staining techniques. The final cytology report should place the tumor in one of three basic categories: benign, malignant, and inconclusive or undetermined. Wherever possible, a histopathologic diagnosis should also be provided, either based on purely cytologic criteria or aided by ancillary techniques.
Conclusion: FNA does not present major complications and permits a swift, preliminary diagnosis in a large number of cases. The method is most effective when the aspiration is performed by an experienced pathologist.