Fine-needle aspiration cytology of Rosai-Dorfman disease of the breast: A case report.

We report the cytologic findings of a case of Rosai-Dorfman disease of the breast in a 52-year-old diabetic woman, initially sampled by fine-needle aspiration biopsy (FNA). The patient presented with a 2-week history of a 3 x 2 cm nodule in the mid-upper area of the left breast. A mammogram taken 6 months prior was negative. FNA smears demonstrated lymphocytes, plasma cells, and large pale cells, with enlarged irregular nuclei, admixed with fragments of fibrous tissue and calcific debris. Lymphophagocytosis (emperipolesis) was scarce. Our diagnosis was atypical lymphohistiocytic proliferation. Flow cytometry was negative, but in the face of a strong clinical suspicion of a lymphoid malignancy, excision was performed. The final diagnosis was Rosai-Dorfman disease (RDD). The differential diagnosis of FNA of breast inflammatory lesions with atypical cytology is discussed, with a review of the literature. The early recognition on FNA of the hallmarks of this rare disease should prevent unnecessary radical surgery. Diagn. Cytopathol. 1999;21:287-291. Copyright 1999 Wiley-Liss, Inc.