FINE-NEEDLE ASPIRATION BIOPSY OF SALIVARY-GLAND LESIONS - A REAPPRAISAL OF PITFALLS AND PROBLEMS

OBJECTIVE: To assess the diagnostic value of fine needle aspiration bi opsy in individual lesions of the salivary glands. STUDY DESIGN: Durin g a 16-year period (1979-1995), 841 salivary gland lesions were invest igated by fine needle aspiration with cytologic examination. The lesio ns affected the parotid gland area in all cases except 85 nr rd 19, re spectively, in which the submandibular gland and oral cavity (more oft en the palate) were involved. RESULTS: Approximately 3% (25/841) of th e aspirates were inadequate, and in 97% of cases they represented the result of samplings performed outside our institution. The 816 diagnos tic aspirates comprised 245 cases negative for tumor cells (benign cys ts, inflammatory, malformed, degenerative lesions), 571 positive for t umor cells (benign; malignant; not otherwise specified [NOS]); metasta tic to the salivary gland tissue; or to the intraparotid or periparoti d lymph nodes). Among the 245 cases negative for tumor cells, 36 under went surgery, and the absence of a neoplasm was histologically confirm ed in all cases but one (a low grade mucoepidermoid carcinoma, underdi agnosed as a retention cyst). Among the 571 patients having a cytologi c diagnosis positive fbr tumor cells, in 518 the lesion was removed an d the tumor nature confirmed. The cytologic diagnosis of a neoplastic lesion del demonstrated a good correlation with histology except in an oncocytic adenoma diagnosed as a Warthin's tumor, in a basal cell ade noma diagnosed as pleomorphic adenoma, in a low grade mucoepidermoid c arcinoma of the palate diagnosed as a polymorphous low grade adenocarc inoma and in a vegetative intravascular hemangioendothelioma diagnosed as a possible malignant tumor, NOS. CONCLUSION: The accuracy was 97%, the sensitivity to the presence of a tumor 98% and the specificity fo r absence of a neoplasm 98%. Despite the relative rarity of salivary g land tumors, if established diagnostic criteria are present and strict ly observed, the great majority of the common variants of the nonneopl astic and both benign and malignant salivary gland tumors can be diagn osed with a high level of accuracy. There remains a proportion of ''pr oblem cases'' due to the rarity of the lesions, and in these circumsta nces the uncertainty must be conveyed to the surgeon openly, leaving t he diagnosis open, with a few suggested differential diagnoses.