The false alarm: Rosai–Dorfman disease of breast: case report

Abstract

Abstract Introduction Rosai–Dorfman disease is a rare disorder caused by benign proliferation of histiocytes and thus also called sinus histiocytosis with massive lymphadenopathy. It is typically known to involve lymph nodes but can also affect extra nodal sites with breast involvement being extremely rare. This disease is known to mimic malignancy clinically and on imaging. The final verdict is through histopathological evaluation. Case presentation We present a case of a 21-year-old female who presented with a palpable suspicious lump in right breast. Ultrasound, mammogram and MRI breast were done followed by fine needle aspiration, which showed lymphocytes and occasional histiocytes, which is suggestive of a lymphoid process. Surgical excision was done due to high suspicion of low-grade angiosarcoma in spite of a negative cytology. Diagnosis of Rosai–Dorfman disease was concluded after histopathological evaluation and was further confirmed by immunohistochemical staining by immunohistochemical markers S-100 and CD68. Conclusion Rosai–Dorfman disease can present as low-grade angiosarcoma clinically as well as on imaging. There is a need for high level of suspicion to rule out benign mimics of malignancy to avoid radical surgery. Final diagnosis is by histopathology along with immunohistochemical staining.