Primary amyloid tumor of the breast: a case report and review of the literature.

We present a case of primary amyloid tumor of the breast. Although isolated amyloidosis of other organs occurs frequently, it is extremely rare in the breast: only seven well-documented cases have been reported. Our case has the additional unusual feature of belonging to the amyloid AA type of amyloid instead of the more common amyloid AL type. Immunohistochemical studies are documented. The clinical and pathologic characteristics of all of the reported cases are tabulated. These cases suggest that primary amyloid tumor in the breast has the following clinicopathologic features: it affects postmenopausal women between the ages of 54 to 82 years (mean, 68 yr), involves the right breast more often than the left (ratio, 3:1), is clinically frequently misdiagnosed as carcinoma, and probably has a diverse pathogenesis.