Grenier Karl, Altinel Gulbeyaz, Dastani Zari, Omeroglu Atilla
Department of Pathology, McGill University Health Center, 1001 Decarie Blvd, Montreal, Québec, Canada H4A 3J1.
Département de Pathologie, Centre Hospitalier de Lanaudière, 1000 Boulevard Sainte-Anne, Saint-Charles-Borromée, Québec, Canada J6E 6J2.
Case Rep Pathol. 2020 Oct 7;2020:8879035. doi: 10.1155/2020/8879035. eCollection 2020.
Epithelial-myoepithelial carcinoma of the breast is a rare biphasic tumor composed of intermixed malignant epithelial and myoepithelial components. Myoepithelial cells are known to adopt varied morphologies, including spindle, chondroid, clear cell, and rhabdoid morphologies, and can represent a diagnostic challenge when isolated on biopsy. Rhabdomyosarcoma, phyllodes tumor, metaplastic carcinoma, and myoepithelial carcinoma are primary breast tumors that all have been shown to exhibit rhabdoid features, whether representing true differentiation or morphological mimic. We here report an epithelial-myoepithelial carcinoma of the breast with rhabdoid features in a 76-year-old woman. The rhabdoid-appearing myoepithelial cells are negative for myogenin, consistent with a rhabdoid-like morphology rather than a true rhabdoid differentiation, comparably to previously described myoepithelial carcinoma with rhabdoid features. To our knowledge, this is the first reported case of epithelial-myoepithelial carcinoma of the breast with rhabdoid features and thus adds another entity to the differential diagnosis of breast lesions with rhabdoid features.
乳腺上皮-肌上皮癌是一种罕见的双相性肿瘤，由恶性上皮成分和肌上皮成分混合组成。已知肌上皮细胞具有多种形态，包括梭形、软骨样、透明细胞和横纹肌样形态，在活检时单独出现时可能构成诊断挑战。横纹肌肉瘤、叶状肿瘤、化生性癌和肌上皮癌是原发性乳腺肿瘤，所有这些肿瘤都已被证明可表现出横纹肌样特征，无论是代表真正的分化还是形态学上的模仿。我们在此报告一例76岁女性患有具有横纹肌样特征的乳腺上皮-肌上皮癌。出现横纹肌样的肌上皮细胞肌生成素呈阴性，与横纹肌样形态而非真正的横纹肌样分化一致，与先前描述的具有横纹肌样特征的肌上皮癌相似。据我们所知，这是首例报告的具有横纹肌样特征的乳腺上皮-肌上皮癌病例，因此为具有横纹肌样特征的乳腺病变的鉴别诊断增添了另一种实体。
