Primary lymphomas of the thyroid gland: a review with emphasis on diagnostic features

The information about primary lymphomas of the thyroid--a rare form of thyroid tumor and a rare form of lymphoma as well--is dispersed in numerous scientific publications. Recent developments in the field of lymphoid neoplasias, in particular the recognition of mucosa-associated lymphoid tissue (MALT) and the characterization of its distinctive type of lymphomas, has drawn new attention to primary lymphomas of the thyroid and has provided new insights into this field of thyroid pathology. In this paper we review the pathogenesis and the clinicopathologic features of primary lymphomas of the thyroid, we discuss the diagnostic basis and the strategies for differential diagnosis, and we address some recent data that may provide additional pathways to further our understanding of those rare thyroid diseases.