Fine needle aspiration cytology of lymphoproliferative lesions of the oral cavity

Objective: Oral cavity non-Hodgkin lymphoma (OCL) is a rare condition that may be clinically and radiologically indistinguishable from other pathologies of the mouth. A complete excision or adequate biopsy of the OCL may be difficult. Fine needle aspiration (FNA) cytology has been successfully utilized in the pre-operative diagnosis of oral masses and in lymphoma involving other anatomical areas. Our experience with FNA pre-operative cytological diagnosis of 16 OCLs is reported herein. Methods: The results of FNA cytology on 16 consecutive lymphoproliferative lesions of the oral cavity collected over an 8-year period in three institutions were retrieved. Sampled lesions were submucosal masses of different sizes bulging into the oral cavity. Rapid on-site evaluation (ROSE) and routine cytological staining were performed. Immunocytochemistry (ICC), flow cytometry (FC) and polymerase chain reaction (PCR) of the IGH (immunoglobulin heavy) locus were performed on additional passes according to ROSE. Results: Fourteen OCLs, one myeloma and one florid reactive lymphoid hyperplasia (FRLH) were diagnosed by FNA. OCLs were diagnosed as large B-cell (eight cases) and small B-cell (six cases) lymphomas. Histology revealed eight diffuse large B-cell lymphomas (DLBCL), four lymphomas of mucosa-associated lymphoid tissue (MALT), two follicular lymphomas and one FRLH; no false-negative or false-positive results were diagnosed, but accurate subclassification was obtained in four cases only. Conclusions: FNA diagnosis of OCLs may be hampered by the rare incidence, anatomical context and difficulties in obtaining a sufficient amount of cells. Ancillary techniques should be used according to ROSE; a pre-operative FNA cytology diagnosis can avoid unnecessary extensive surgery and speed up the institution of therapeutic procedures.