Oral pseudolymphoma: a report of two cases.

Although 2% to 10% of lymphomas present first in the oral cavity and lymphomas are the third most common oral malignancy, pseudolymphoma is a very infrequent problem within oral pathology. Two cases of oral pseudolymphoma are presented. Both were old persons with an infiltrative lesion on the oral mucosa that histologically showed a dense polymorphous infiltrate with some nuclear atypia that raised the problem of lymphoma versus pseudolymphoma. Both lesions disappeared with no relapse after 2-years' follow-up. Histologically, case 1 was mainly a lymphohistiocytic infiltrate whose histiocytic component showed nuclear features that mimicked Hodgkin's cells. In case 2, the infiltrate was mainly composed of histiocytes and eosinophils. The suspicion of malignancy here was a consequence of a high mitotic rate of histiocytes and of the large hyperchromatic nuclei of the intraepithelial lymphocytes. Similarities and differences with other pseudomalignant (lymphomatoid papulosis and atypical histiocytic granuloma) and inflammatory (traumatic ulcerative granuloma with stromal eosinophilia) disorders, as well as with some histiocytoses, are discussed. In the absence of a wider experience on this subject, an objective description of new cases seems appropriate.