Malignant Lymphoma of the Thyroid

Thyroid lymphoma is a relatively rare disease, but has attracted the attention of many investigators because of its putative relationship with chronic lymphocytic thyroiditis (CLTH). The definite diagnosis of thyroid lymphoma, especially the histologic distinction from small cell carcinoma or CLTH, has been problematical and even regarded as impossible during the past decades. Recent progress in immunological methods including moltxular biology have resolve'd many of the diagnostic problems in this field, thereby providing a scientific basis for approaching these diseases. In this review, we have summarized the results of our recent study on thyroid lymphoma reviewing the pertinent literature. Briefly, we have discussed the important role of CETH in the etiology of thyroid lymphoma; the histologic classification of thyroid lymphoma, with special emphasis on the rellatively high incidence of intermediate lymphocytic lymphoma; the B-cell nature of proliferating cells in thyroid lymphoma; the prognostic significance of the histologic classification Working Formulation and other clinical factors; local immunologic conditions in the thyroid affected by lymphoma compared with those encountered in CLTH alone and the positive role of aspiration cytology in the early detection of thyroid lymphoma.