PRIMARY LOCALIZED AMYLOID TUMOR OF THE BREAST WITH OSSEOUS METAPLASIA

A case of primary localized amyloid tumor of the breast is described. It is an extremely rare condition and has not been seen in literature in Japan. A 76-year-old woman visited a hospital because of a painless , hard mass of the right breast. A relatively well demarcated, calcifi ed mass was excised under clinical diagnosis of fibroadenoma. Histolog ically, massive eosinophilic amorphous material was deposited in breas t stroma. It was stained red-orange by Congo red and displayed apple-g reen birefringence under polarized light, The staining persisted after incubation with KMnO4 and immunolabeling by immunoglobulin chi-light chain antiserum, consistent with the amyloid of AL (A chi) type. Osseo us metaplasia with bone marrow cavity, foreign body type giant cells i n response to amyloid, and scattered plasma cell infiltration were als o recognized. Osseous metaplasia in the breast amyloid tumor has been reported in only one case before. To date, the patient has not develop ed any clinical or laboratory evidence of systemic amyloidosis or mult iple myeloma.