Fine-Needle Aspiration Cytology of Soft Tissue Sarcoma: Benefits and Limitations

Purpose. Examine the benefits and limitations of fine-needle aspiration cytology (FNA) used as the definitive diagnostic method before treatment. Method. Review of the 25 year experience at a multidisciplinary musculo-skeletal centre where FNA is the primary diagnostic approach to soft tissue sarcoma in the extremities and trunk wall and the experience of various experts in the field. Results. FNA has several benefits compared with coarse needle or open surgical biopsy. The most important are rapid preliminary diagnosis, no need for hospitalization and anaesthesia, negligible complications and fear for tumour cell spread. With the collected experience gained during the years a reliable diagnosis of sarcoma is the rule in general and specific-type diagnoses are possible in many histotypes, especially when the cytologic examination is supplemented with ancillary diagnostics. The most important limitations are inability to hit small deep-seated sarcoma and some diagnostic pitfalls such as the correct diagnosis of spindle cell neoplasms, variants of benign lipomatous tumours and ‘new soft tissue tumour entities’. Discussion. Optimal use of FNA calls for certain requirements such as centralization, experience in soft tissue tumour cytology–histopathology, the FNA technique and close co-operation between the orthopaedic surgeon and cytopathologist.