Objective:

To enhance understanding of breast Rosai-Dorfman Disease (RDD) and inform clinical management practices based on a rare case report.

Approach:

• Case Report: A 69-year-old woman presented with a palpable mass in the right breast, which was evaluated through imaging and biopsy.
• Diagnostic Process: Ultrasound and mammography suggested a malignant lesion, leading to a core needle biopsy and subsequent wide local excision.
• Pathologic Diagnosis: The lesion was diagnosed as extranodal Rosai-Dorfman disease based on morphology and immunohistochemistry.

Key Findings:

• Breast RDD is rare and typically presents as a painless palpable mass.
• Imaging studies may suggest malignancy, necessitating biopsy for accurate diagnosis.
• Immunohistochemistry is crucial for confirming RDD, showing characteristic markers such as S100 and CD68.
• The case highlights the diagnostic challenges due to the rarity of breast RDD.

Interpretation:

Breast RDD can mimic malignancy, highlighting the importance of thorough diagnostic evaluation.

Limitations:

• Limited number of reported cases of breast RDD restricts the establishment of consensus on diagnosis and treatment.
• The case study reflects a single patient experience, which may not be generalizable.

Conclusion:

The case illustrates the diagnostic challenges and the need for increased awareness of breast RDD among clinicians.