Parotid gland mucose associated lymphomas and their cytologic mimics

Although the parotid is a target for myoepithelial sialadenitis and lymphom as of mucosa associated lymphoid tissue (MALTomas), MALTomas are rare and h ave not been well characterized in the cytology literature. We examine fine needle aspiration biopsies from 19 lymphoid lesions of the parotid gland w ith particular emphasis on MALTomas and their cytologic look-a-likes. Purel y on cytology it is difficult to distinguish with certainty a MALToma from a late-phase reactive lymph node. Both conditions were predominantly compos ed of small mature appearing lymphocytes and both occasionally had larger l ymphocytes with tingible body macrophages, By contrast, the diagnosis of no n-MALT lymphoma was usually straight forward, as they had overt cytologic a typia. In applying fine needle aspiration biopsy to large or persistent lym phoid lesions of extra-nodal sites like the parotid gland, we recommend the liberal use of flow cytometric analysis to distinguish between reactive ly mph nodes and MALToma and to more precisely classify non-MALT lymphomas. Co pyright (C) 2001 by W.B. Saunders Company.