ABSTRACT

Objective

To investigate the clinicopathologic features and immunophenotype of primary squamous cell carcinoma of the breast (PSCCB) with HER2 overexpression.

Methods Two cases of PSCCB with HER2 overexpression were retrospectively reviewed, and the pathological features, immunophenotype and prognosis were discussed.

Results The tumor showed malignant squamous cells arranged in sheets, groups and nests, forming keratin-pearl and intercellular bridges. Immunohistochemical (IHC) analysis showed that the tumor cells were positive for 34βE12, p63, CK5/6, E-cadherin and P120, while negative for ER and PR. Furthermore, HER2 overexpression showed strong continuous expression in cell membrane with a score of 3+ by IHC, or amplification by FISH.

Conclusions PSCCB is a rare tumor in breast cancer and HER2 overexpression is rather unusual in PSCCB. The diagnosis mainly depends on the clinicopathologic features together with the immunophenotype. HER2 positive indicates poor prognosis. However, targeted therapy for HER2 may be a new hope for patients.

中文翻译：

---

乳腺原发性鳞状细胞癌：两例 HER2 过度表达的报告

摘要

客观的

探讨 HER2 过表达的原发性乳腺鳞状细胞癌 (PSCCB) 的临床病理特征和免疫表型。

方法回顾性分析2例HER2高表达的PSCCB病例，讨论其病理特征、免疫表型及预后。

结果肿瘤呈片状、群状、巢状排列的恶性鳞状细胞，形成角蛋白珠和细胞间桥。免疫组织化学（IHC）分析显示肿瘤细胞对 34βE12、p63、CK5/6、E-cadherin 和 P120 呈阳性，而对 ER 和 PR 呈阴性。此外，HER2过表达在细胞膜中表现出强烈的连续表达，IHC评分为3+，或FISH扩增。

结论PSCCB是一种罕见的乳腺癌肿瘤，HER2过表达在PSCCB中较为罕见。诊断主要取决于临床病理特征和免疫表型。HER2 阳性表明预后不良。然而，针对 HER2 的靶向治疗可能是患者的新希望。