Sonographic Manifestation of Thyroid's Rosai-Dorfman Disease

Rosai-Dorfman disease (RDD) is a rare and benign histiocytic proliferative disorder of unknown etiology. It can affect all age groups, particularly young adults. The typical clinical manifestation is painless, bilateral, massive cervical lymphadenopathy with or without extra nodal involvement, along with fever, weight loss, and night sweats. However, thyroid involvement is very uncommon. The ultrasonographic manifestations of RDD are rarely reported. A case of RDD involving the thyroid that was recorded in our hospital PACS system during 2002–2010 is reported here, which was initially misdiagnosed as non-Hodgkin’s lymphoma (NHL). In our case, ultrasonography revealed diffuse enlargement of whole thyroid glands with heterogeneous hypoechogenicity. Areas of linear hyperechogenicity were noted on the sonograms with multiple enlarged nodes over the cervical, supraclavicular, and submandibular areas. Though not specific, in order to avoid unnecessary surgery or a total thyroidectomy, ultrasonography and ultrasonography-guided core needle biopsy should be performed to establish an accurate diagnosis.