Li Yanan, Wu Kefeng, Li Huiying, Wu Chun
Department of Clinical Laboratory Diagnosis, Shijiazhuang Pingan Hospital, Hebei Medical University, Shijiazhuang, China.
Department of Oncology, Shijiazhuang Pingan Hospital, Hebei Medical University, Shijiazhuang, China.
AME Case Rep. 2024 Nov 21;9:20. doi: 10.21037/acr-24-138. eCollection 2025.
Primary breast squamous cell carcinoma (PBSCC) is a unique histopathological type of breast cancer. The majority of current case reports of PBSCC are triple-negative tumors with poor prognosis. Due to its heterogeneous clinical course, no unified management is achieved. Here, we report a human epidermal growth factor receptor 2 (HER2) positive case with good clinical outcome, which may contribute to the development of appropriate guidelines and imprecise management of PBSCC.
A 45-year-old female presented with a painless mass in the medial-upper quadrants of right breast and the imaging examination suggested a malignant tumor. She received modified radical mastectomy and axillary sentinel lymph node dissection of the right breast, and the pathological diagnosis was squamous cell carcinoma with HER2 over-expression. Subsequently, she underwent post-operative chemotherapy regimen of doxorubicin, cyclophosphamide, T-docetaxel and trastuzumab (AC-TH) and then received maintenance treatment with trastuzumab and pertuzumab. Clinical follow-up suggests that she had achieved clinical complete remission and has survived for over 4 years.
The diagnosis of PBSCC relies on histomorphology, due to non-specific imaging manifestations. Immunohistochemical (IHC) staining helps to clarify the pathological type, hormone receptor status, HER2 amplification and programmed cell death ligand 1 (PD-L1) expression, which is essential for clinical decision-making. HER2-positive PBSCC patients can benefit from AC-TH chemotherapy and 1-year anti-HER2 therapy is necessary to good prognosis. If possible, dual anti-HER2 therapy combined with trastuzumab and pertuzumab is recommended. Finally, positive clinical prognosis of PBSCC may be attributed to early detection, immediate surgery, precise diagnosis and proper adjuvant treatment strategy.
原发性乳腺鳞状细胞癌（PBSCC）是一种独特的乳腺癌组织病理学类型。目前大多数PBSCC病例报告为预后较差的三阴性肿瘤。由于其临床病程异质性，尚未实现统一管理。在此，我们报告一例人表皮生长因子受体2（HER2）阳性且临床结局良好的病例，这可能有助于制定PBSCC的适当指南并改善其不精确的管理。
一名45岁女性因右乳内上象限无痛性肿块就诊，影像学检查提示为恶性肿瘤。她接受了右乳改良根治术及腋窝前哨淋巴结清扫术，病理诊断为HER2过表达的鳞状细胞癌。随后，她接受了多柔比星、环磷酰胺、T-多西他赛和曲妥珠单抗（AC-TH）的术后化疗方案，然后接受曲妥珠单抗和帕妥珠单抗维持治疗。临床随访表明她已实现临床完全缓解且存活超过4年。
由于PBSCC的影像学表现不具特异性，其诊断依赖组织形态学。免疫组织化学（IHC）染色有助于明确病理类型、激素受体状态、HER2扩增及程序性细胞死亡配体1（PD-L1）表达，这对临床决策至关重要。HER2阳性的PBSCC患者可从AC-TH化疗中获益，1年的抗HER2治疗对良好预后是必要的。若可能，推荐曲妥珠单抗和帕妥珠单抗联合的双抗HER2治疗。最后，PBSCC良好的临床预后可能归因于早期发现、及时手术、精确诊断及恰当的辅助治疗策略。
