Fine-needle aspiration cytology of lymphoid lesions of the salivary gland: a review of 35 cases

OBJECTIVE: The aim of this study was to evaluate the effectiveness of fine-needle aspiration (FNA) in the diagnosis of primary lymphoid processes of the salivary gland. DESIGN: A retrospective study. METHOD: Between 1987 and 1994, 35 patients who underwent fine-needle aspiration (FNA) of the salivary gland had a diagnosis of a primary lymphoid process. Most presented with palpable parotid (28 patients) or submandibular (4 patients) gland masses which prompted a clinical diagnosis of pleomorphic adenoma. FNA was performed with immediate on-site evaluation. Flow cytometric cell-surface-marker analysis was performed in 28 of the 35 cases to determine the clonality of the B-cell proliferations. RESULTS: Sixteen cases of reactive hyperplasia and nine cases of malignant lymphoma diagnosed by FNA were confirmed by subsequent histopathologic examination. Lymphoma was confirmed in six of eight cases diagnosed as suspicious for lymphoma by FNA. Hodgkin's disease was suspected but not confirmed in one case and was diagnosed as a probable Warthin's tumour in another case. In all cases, the FNA diagnosis of either a reactive or malignant lymphoid process was unexpected and influenced the patient's further management. For patients diagnosed with an intraparotid lymph node, surgery could be deferred for a short period with the hope that the lymphadenopathy would spontaneously regress. For patients with a preoperative FNA diagnosis of lymphoma, a more limited biopsy could be performed, thereby reducing the operative risk to the patient and plans to process the tissue according to the institution's lymphoma protocol could be made. CONCLUSION: Clinically, reactive intraparotid lymph nodes and lymphomas present as parotid enlargements that are indistinguishable from pleomorphic adenomas. FNA is the only method of accurately establishing a preoperative diagnosis in these patients.