Extranodal Rosai-Dorfman disease presenting as a suspicious breast lump: An infrequent but elusive differential diagnosis. A case report

Rosai-Dorfman disease represents a very rare idiopathic disorder mainly characterized by sinus histiocytosis and massive lymphadenopathy. In even rarer occasions (< 43%), extranodal involvement has been reported, with one of the least common presentations being isolated breast affection (< 1%). We report the case of a 64-year-old woman who debuted with a suspicious breast lump and underwent a prolonged study protocol before a proper histopathological diagnosis could be obtained. Surgical management was effective, and follow-up shows no signs of recurrence. In the context of ruling out breast malignancy, even rare alternatives should be considered when a diagnosis eludes us.