乳腺基质分泌型化生性癌的临床病理观察及预后分析

Matrix-producing metaplastic carcinoma： a clinicopathologic and prognostic analysis of 16 cases with review of literature

目的探讨乳腺基质分泌型化生性癌（MPC）的临床病理特征、免疫表型和预后。方法回顾性分析2002至2012年间16例乳腺MPC的临床病理特点和免疫表型。随访获取MPC患者的预后信息，并与同期非特殊型浸润性乳腺癌进行配对，比较两组肿瘤的无复发生存和总体生存。结果患者均为女性，年龄29—69岁（平均48岁）。肿瘤大小平均为4cm。多数肿瘤界限清楚，呈结节状、膨胀性生长。镜下浸润性癌直接向软骨／软骨黏液样基质过渡，呈现外周型和弥漫型两种分布模式。基质分泌癌成分占整个肿瘤比例的10％～80％。MPC具有三阴型免疫表型（雌激素受体、孕激素受体和HER2均阴性）并较高水平表达S-100蛋白和基底型细胞角蛋白。软骨／软骨黏液样基质呈阿辛蓝染色阳性。MPC的无局部复发生存（P=0．010）、无远处转移生存（P=0．01）和总体生存（P=0．017）均低于配对的非特殊型浸润性癌。结论乳腺MPC具有独特的形态学特征和免疫表型，属于侵袭性强的化生性癌亚型。

Objective To study the elinicopathologic features, immunophenotype and prognosis of matrix-producing metaplastic carcinoma （MPC）. Methods Sixteen cases of MPC diagnosed between 2002 and 2012 in West China Hospital were identified. The clinieopathologic features were analyzed. Immunohistochemistry for E-eadherin, S-100 protein, CK5/6, HCK, PCK, CK7, CK8, p63, SMA, EMA, CD99, MSA, CK14, EGFR, ER, PR, HER2 and Ki-67 was performed with EnVision method. The clinical outcome was evaluated and compared to matched controls of invasive duetal carcinoma. Results All patients were women and ranged in age from 29 to 69 years （ median age 48 years）. The median size of primary tumor was 4 cm. Most of the tumors were well-circumscribed with expansile and multinodular appearance. Histology showed invasive carcinoma with a direct transition from carcinoma to cartilaginous/ ehondromyxoid matrix without an intervening spindle cell component. Tumor distribution was either nodular or diffuse. The matrix component accounted for 10% - 80% of the tumor volume. All the tumors were strongly positive for S-100 protein and basal-like eytokeratin with triple negative phenotype （ER, PR and HER2 negative）. Alcian blue stain was positive for the eartilaginous/ehondromyxoid matrix. Compared with invasive ductal carcinoma, patients with MPC had increased locoregional recurrence （P = 0. 010） , increased distant recurrence （P = 0. 011 ） and shorter disease-free survival （ P = 0. 017 ）. Conclusions MPC is a rare variant of mammary metaplastie carcinoma with unique characteristics of morphology and immunohistochemical staining pattern. This subtype seems to have aggressive biologic behavior.