乳腺低级别腺鳞癌临床病理分析及文献复习

Low-grade adenosquamous carcinoma of the breast: a clinicopathologic analysis and review of literatures

目的 探讨乳腺低级别腺鳞癌的临床病理特征、免疫表型特点及鉴别诊断要点。方法 分析1例乳腺低级别腺鳞癌的临床病理特征、免疫表型特点,并复习相关文献。结果 患者女性,52岁,因发现左乳肿块入院。大体上,乳腺实质中查见一形态不规则的肿块,大小4.5 cm×3 cm×3 cm,切面灰白、灰黄,实性、质稍硬,与周围组织分界不清。组织学显示:肿瘤由分化良好的小腺管和伴有鳞化的实性上皮细胞巢组成,杂乱无章地分布于梭形细胞的间质中。间质中伴有成巢分布的淋巴细胞。免疫表型:肿瘤细胞呈三阴性表达(ER、PR、HER-2均呈阴性),上皮标记CK7、CK5/6在小腺管中呈阳性表达;鳞状分化区域CK5/6、P63阳性;肌上皮标记P63、CD10在小腺管周围呈完全、不连续和缺失的混杂表达模式。结论 乳腺低级别腺鳞癌是一种罕见而独特的乳腺化生性癌,其典型的组织学改变是肿瘤由小腺管和伴有鳞化的实性细胞巢组成。

Objective To study the clinicopathological characteristics, immunophenotype and histological diagnosis of low-grade adenosquamous carcinoma of the breast(LGASC). Methods The clinical and pathological features of one case of LGASC were analyzed, and the related literatures were reviewed. Results A 52-year-old woman presented with a palpable mass lesion of her left breast. The tumor measured 4.5 cm in its maximum diameter and was ill-circumscribed. The cut surface was grayish-pale in color. Microscopically, the tumor was composed of well differentiated glandular structures with scattered squamous differentiation accompanied by haphazard arrangement of spindle cell stroma. Clusters of lymphocytes were observed at the periphery of lesion. Immunophenotyping showed that the tumor cells were triple nagtive(ER, PR and HER2),the glands were positive for CK7 and CK5/6 while the squamous differentiation area were positive for P63 and CK5/6. Myoepithelial markers(P63 and CD10) demonstrated a spectrum of complete, discontinuous, or absent staining around lesional glands. Conclusion Low-grade adenosquamous carcinoma of the breast(LGASC) is a rare and unique variant of metaplastic carcinoma with a favourable prognosis. Its typical histological changes are composed of glandular and squamous elements in a spindle cell background associated with a lymphocytic stromal reaction.