Inaccuracy of fine needle aspiration biopsy.
Fine needle aspiration biopsy (FNAB) of orbital tumors has been recently advocated as a reliable diagnostic modality. An accuracy rate of 92% has been claimed by some authors. This figure remains unproven as most patients have not undergone simultaneous pathologic examination. We recently performed FNAB on 34 patients at the time of surgical biopsy. The procedure was performed with direct visualization and the tissue was obtained and prepared as described by Kennerdell. A definitive surgical biopsy was then obtained and submitted for routine pathologic examination. Cytologic diagnosis has been accurate in less than half of the cases biopsied. Reliance on fine needle aspiration biopsy alone in some patients would have resulted in inappropriate therapy. Fine needle aspiration biopsy should be limited to strongly suspected cases of orbital metastases or secondary tumors.