Unencapsulated lymphoid aggregates that are normally present in the oral cavity (primarily on the soft palate, the foliate papillae on the posterolateral aspects of the tongue dorsum, and the anterior tonsillar pillar) can increase in size as a result of benign (reactive) processes as well as lymphoid neoplasms. In the absence of other evidence of lymphoid disease, diagnosis of intraoral swellings of this type may be difficult even when adequate biopsy specimens are obtained. The differential diagnosis of such swellings includes benign (follicular) lymphoid hyperplasia of the palate;reactive hyperplasia of a buccal, facial, or submandibular lymph node, possibly associated with a chronic periapical or periodontal infection; viral infection (eg, Epstein-Barr virus) or a speciļ¬c bacterial infection (eg, mycobacteria, Rochemela); and lymphoproliferative disease or lymphoma. Histologic criteria based on architectural, cytologic, and immunologic (leukocyte monoclonal antigen-antibody reactions) features of the lymphoid aggregate have been described in recent years.