Amyloid tumors of the breast are extremely rare. Few isolated cases have been reported to date. Amyloid involvement of the breast has no specific diagnostic features on mammography; on occasion, this causes diagnostic challenges. In this paper, the case of a 58-year-old woman with an amyloid tumor of the breast, which developed secondary to long-standing rheumatoid arthritis, is presented. She presented with a palpable mass in her right breast, which led to an erroneous clinical diagnosis of breast cancer. The unusual mammography findings are demonstrated and the differential diagnosis, in light of the radiological images and the clinical and pathologic features, is discussed.
* Amyloid tumor of the breast is extremely rare, and only a very small number of cases have been reported to date.
* Although amyloid breast tumors are rare, they can be confused with breast carcinomas.
* No clinical or radiological finding has been identified as diagnostic for breast amyloidosis.
* To avoid misdiagnosis, close cooperation is necessary among clinicians and pathologists.