Extranodal Rosai-Dorfman Disease of Breast Mimicker of Breast Malignancy.

Rosai-Dorfman-Destombes (RDD) disease is also known as sinus histiocytosis with massive lymphadenopathy. It is an uncommon heterogeneous disease of children and young adults. Most of the patients with RDD generally present with painless lymphadenopathy, while extranodal and multisystem manifestation of the disease is unusual. The diagnosis is based on the imaging with clinicopathological correlation. Flourine-18 fluorodeoxyglucose positron emission tomography/computed tomography is useful for the initial staging of the RDD lesions, which have similar appearance and avidity like intermediate and high-grade lymphomas. Here, we present the case of a 55-year-old female presented with left breast mass that turned out to be the extranodal Rosai-Dorfman disease.