Noor Rida, Lajara Sigfred, Bhargava Rohit
Department of Pathology, Faisalabad Medical University, Faisalabad, PAK.
Department of Pathology, UPMC (University of Pittsburgh Medical Center) Presbyterian-Shadyside Hospital, Pittsburgh, USA.
Cureus. 2023 Dec 10;15(12):e50265. doi: 10.7759/cureus.50265. eCollection 2023 Dec.
Metaplastic breast carcinoma represents a diverse category of invasive breast cancers distinguished by the transformation of neoplastic epithelial cells into squamous cells or cells with mesenchymal appearance. Matrix-producing breast carcinoma is a variant of metaplastic breast carcinoma, an exceedingly uncommon malignancy accounting for less than 1% of all breast tumors. The precise origin of this tumor remains elusive; some molecular research points to a potential derivation from myoepithelial cells, while other studies emphasize the possibility of neoplastic transformation originating from multipotent stem cells. We report a case of recurrent matrix-producing breast carcinoma. The patient presented with a breast mass. The tumor cells displayed a lack of reactivity for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER2), and exhibited a Ki-67 proliferation index of approximately 40%. Additionally, the tumor cells demonstrated significant reactivity for cytokeratins and S100. The patient underwent surgery, radiation, and chemotherapy and then developed metastasis to the lower lobe of her left lung, seven years after primary diagnosis. Diagnosis of metastasis was confirmed by comparing the metastasis to the primary tumor and staining with a panel of immunohistochemical stains. The patient is currently undergoing chemotherapy and immunotherapy.
化生性乳腺癌是一种侵袭性乳腺癌，其特征是肿瘤上皮细胞转化为鳞状细胞或具有间充质外观的细胞。产基质性乳腺癌是化生性乳腺癌的一种变体，是一种极为罕见的恶性肿瘤，占所有乳腺肿瘤的比例不到1%。这种肿瘤的确切起源尚不清楚；一些分子研究指出其可能起源于肌上皮细胞，而其他研究则强调肿瘤转化可能源自多能干细胞。我们报告一例复发性产基质性乳腺癌病例。患者因乳腺肿块就诊。肿瘤细胞对雌激素受体（ER）、孕激素受体（PR）和人表皮生长因子受体2（HER2）均无反应，Ki-67增殖指数约为40%。此外，肿瘤细胞对角蛋白和S100有显著反应。患者接受了手术、放疗和化疗，在初次诊断七年后出现左肺下叶转移。通过将转移灶与原发肿瘤进行比较并用一组免疫组织化学染色进行染色，确诊为转移。患者目前正在接受化疗和免疫治疗。
