[257] Mammary Amyloidosis: A Series of 44 Cases from a Single Institution

Samar M Said, Carol Reynolds, Rafael E Jimenez, Beiyun Chen, Julie A Vrana, Jason D Theis, Ahmet Dogan, Sejal S Shah. Mayo Clinic, Rochester, MN

Background: Amyloidosis is a disorder characterized by extracellular accumulation of Congo red positive fibrillar deposits resulting from abnormal folding of proteins. More than 20 precursor proteins of amyloid have been identified so far, with the most common types being immunoglobulin light-chain (AL) amyloidosis secondary to plasma cell dyscrasia and reactive secondary (AA) amyloidosis associated with chronic inflammatory diseases. AL amyloidosis is usually systemic and commonly involves the heart, kidney, gastrointestinal tract, and tongue. Breast involvement by amyloidosis has rarely been reported.
Design: Forty-four cases of mammary amyloidosis diagnosed from 1995 to 2011 were identified at our institution. In 4 patients, the breast biopsies were performed at our medical center. In the remaining cases, the biopsies were performed at outside institutions and materials were sent to us for a second opinion or for amyloid typing by immunohistochemistry and/or mass spectrometry (MS).
Results: The study group included 43 women and 1 man with ages ranging from 36 to 85 yrs (mean 59 yrs). Clinical presentation was breast mass in 12 cases, calcifications in 6 cases and unknown in 26 cases. Amyloid deposition was in the right breast in 22 (50%), in the left breast in 19 (43%), and bilateral in 2 (5%) patients; the site was not indicated in 1 (2%) patient. The type of amyloidosis was AL in 24 cases (14 AL-kappa, 10 AL-lambda) and heavy and light chain (IgA-lambda) in one case. None of the cases showed AA amyloidosis. For the remaining 19 cases, typing was not performed or was inconclusive. MS established the type of amyloid in 16 of 17 (94%) cases tested. In addition to amyloidosis, the breast biopsy showed MALT lymphoma in 13 (30%) cases, plasma cell proliferative disorder in 6 (14%) cases, plasmacytoma in 1 (2%) case and CLL in 1 (2%) case. One patient had concurrent intraductal carcinoma, but none had invasive carcinoma. Of the 16 patients seen in our institution, 7 (44%) had amyloid deposition in one or more organ site (skin 3, lymph nodes 2, heart 2, soft tissue 2, lung/pleura 1, submandibular gland 1, and kidney 1).
Conclusions: Amyloidosis involving the breast is rare and when present is most commonly AL type. With the introduction of MS, the type of amyloid can be determined in the majority of cases. In our study, mammary amyloidosis is associated with concurrent hematologic malignancy in 48% of patients, of which 62% are MALT lymphoma. Involvement of additional organ sites is seen in over one third of our patients. Further work up to rule out hematologic malignancy and/or systemic amyloidosis is recommended.
Category: Breast

Monday, March 19, 2012 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 36, Monday Morning

 

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