Histiocytic non-Hodgkin's lymphoma of Waldeyer's ring.

The most common extranodal site for non-Hodgkin's lymphoma in the head and neck is the lymphoid tissue of Waldeyer's ring. Diffuse histiocytic non-Hodgkin's lymphoma is the most frequent type occurring at all head and neck extranodal sites. The rarity of histiocytic lymphoma in the areas comprising Waldeyer's ring tends to make assembly of a large series of patients for retrospective study quite difficult. Of the 804 patients treated for malignancies in Waldeyer's ring during the years 1948 to 1985 at the Charity Hospital of Louisiana, 26 had lesions classified as histiocytic non-Hodgkin's lymphoma. We present, to our knowledge, the largest series of diffuse histiocytic lymphomas involving Waldeyer's ring.