Malign adenomyoepithelioma of the breast with high Ki-67 index: Case report with the literature review

Abstract

Breast glands and salivary glands can manifest as tumors with similar morphological features. Salivary gland-like tumors of the breast are of two types: tumors with myoepithelial differentiation and those devoid of that. The breast tumors showing pure myoepithelial or epimyoepithelial differentiation are rare. Adenomyoepithelioma (AME) of the breast is a biphasic tumor, identical to the epithelial-myoepithelial cell carcinoma of the salivary gland. Histologically, AME is composed of two cell types; myoepithelial and epithelial. The epithelial component is composed of columnar cells showing features of apocrine cells. The outer layer is composed of clear cells with the immunohistological profile of myoepithelial cells. Our case was a 45-year-old woman presenting with a painless mass located peripherally on her right breast. Grossly, on the cut surface of the excision material a solid, well-circumscribed, white-gray, firm mass was seen. Microscopically, the tumoral lesion was composed of epithelial and myoepithelial components and had lobulated and focally infiltrating margins. Both epithelial and myoepithelial components showed marked pleomorphism, mitotic activity, atypia, and focal necrosis. Immunohistochemically SMA, CD10, p63 and CK5/6 were positive in the myoepithelial component and CK7 was positive in the epithelial component, Ki-67 proliferation index was 20% in the tumor. But estrogen and progesterone receptors were negative. We find our case worthy to report because of the tumor showed high Ki-67 index, and extremely rarity of malignant AME in the breast tissue that it has only rarely been documented in the literature. J Clin Exp Invest 2011; 2 (4): 425-429

Keywords

• Breast, adenomyoepithelioma, malignant, Ki-67

Malign adenomyoepithelioma of the breast with high Ki-67 index: Case report with the literature review

Öz

Meme bezleri ve tükrük bezleri benzer morfolojik özellikler ile karakterli tümörler sergileyebilmektedirler. Memenin tükrük bezi benzeri tümörleri iki tiptir: myoepitelyal diferansiasyon gösteren ve bu diferansiasyondan yoksun olan tümörler. Pür myoepitelyal ya da epimyoepitelyal diferansiasyon gösteren meme tümörleri ise nadirdir. Memenin adenomyoepitelyoması (AME) bifazik bir tümör olup, tükrük bezinin epitelyal-myoepitelyal karsinomu ile özdeştir. Histolojik olarak AME myoepitlyal ve epitelyal olmak üzere iki hücre tipinden oluşmaktadır. Epitelyal komponent, apokrin hücre özellikleri gösteren kolumnar hücrelerden oluşmaktadır. Dış tabaka ise myoepitelyal hücrelerin immün ve histolojik profilini gösteren şeffaf hücrelerden oluşmaktadır. Bizim vakamız, sağ memesinde periferal yerleşimli ağrısız kitle ile başvuran 45 yaşında kadın hasta idi. Makroskopik incelemede, eksizyon materyalinin kesit yüzünde solid, iyi sınırlı, beyaz-gri renkte, sert kitle lezyonu izlendi. Mikroskopik incelemede, tümör epitelyal ve myoepitelyal komponentlerden oluşmakta olup, büyük oranda lobüle, fokal infiltratif marjinler ile karakterli idi. Hem epitelyal hem myoepitelyal komponentte, belirgin pleomorfizm, mitotik aktivite, atipi ve fokal nekrozlar dikkati çekti. İmmünohistokimyasal olarak SMA, CD10, p63 ve sitokeratin 5/6 myoepitelyal komponentte ve sitokeratin 7 epitelyal komponentte pozitif saptandı, Ki-67 proliferasyon indeksi % 20 idi. Östrojen ve progesteron reseptörleri ise negatifdi. Vakamızı meme dokusunda malign AME\'nin oldukça nadir olması, yüksek ki-67 indeksi göstermesi ve literatürde bildirilen birkaç vakadan biri olması nedeni ile bildiriye değer bulduk.

Anahtar Kelimeler

• Meme, adenomyoepitelyoma, malign, Ki-67