Objective: To investigate the accurate diagnosis and differential diagnosis of non-primary solid malignant tumors in breast needle core biopsy. Methods: Twenty-three cases of breast, axilla or neck lymph nodes pathologically diagnosed as non-primary solid malignant tumors were collected at the First Affiliated Hospital of Nanjing Medical University, Nanjing, China from January 2013 to March 2023. The differential diagnoses and diagnostic features were analyzed, based on combining clinical data, histology, and expression characteristics of biomarkers. Results: All patients were female, with age ranging from 29 to 75 years (average 56 years). The average time from the diagnosis of primary tumor to the current diagnosis was 21 months (0 to 204 months).The primary sites included the ovary (9 cases), the lung (5 cases), the gastrointestinal tract (4 cases), the pancreas, intrahepatic bile duct, thyroid gland, nasal cavity and forearm skin (1 case each). No carcinoma in situ was found in any of the cases. The morphological differences were significant among the tumors, but similar to the primary tumors. The tumors of neuroendocrine and female reproductive tract had great morphological and immunophenotypic overlaps with breast cancer. Metastatic lung cancer cells showed obvious atypia and tumor giant cells. The morphology and immunophenotype of metastatic serous carcinoma of female reproductive system might resemble invasive micropapillary carcinoma of the breast. Metastatic adenocarcinoma of the gastrointestinal tract often had features of mucous secretion. Metastatic neuroendocrine tumors were bland in appearance and morphologically similar to solid papillary carcinoma of breast, but negative for ER. TRPS1 was mostly negative (18/23) and variably positive in ovarian (4/9) and intrahepatic bile duct (1/1) tumors. Conclusions: The diagnosis of breast needle core biopsy specimen should be combined with clinical history, imaging study, and careful examination of histological features, such as presence of in situ component, morphological similarity between the primary and metastatic tumors, and using appropriate markers to differentiate the primary from metastatic tumors.
目的： 探讨乳腺穿刺病理中对非原发实体恶性肿瘤的精准诊断及鉴别诊断。 方法： 收集南京医科大学第一附属医院2013年1月至2023年3月行乳腺、腋窝或颈部淋巴结空心针穿刺标本，病理诊断为乳腺非原发实体恶性肿瘤的病例23例，结合其临床资料、形态学及免疫标志物表达特征分析鉴别思路和诊断线索。 结果： 23例患者均为女性，平均年龄56岁（29~75岁），原发与转移间隔平均时间为21个月（0~204个月）。原发部位包括卵巢（9例）、肺（5例）、胃肠道（4例）、胰腺（1例）、肝内胆管（1例）、甲状腺（1例）、鼻腔（1例）和前臂皮肤（1例）。转移性肿瘤镜下均未见原位癌成分，形态学差异大，与原发肿瘤具有相似性，但神经内分泌肿瘤、女性生殖系统来源的肿瘤与乳腺癌具有极大形态学和免疫表型的重叠。转移性肺癌细胞异型性明显，常见瘤巨细胞；女性生殖系统来源浆液性癌形态学与免疫表型可酷似乳腺浸润性微乳头状癌；消化道转移性腺癌常具有黏液分泌特征；转移性神经内分泌肿瘤形态温和貌似实性乳头状癌，但雌激素受体阴性。TRPS1通常呈阴性表达（18/23），其中卵巢（4/9）及肝内胆管（1/1）来源肿瘤呈强弱不等的阳性表达。 结论： 乳腺穿刺标本诊断时需结合临床病史及影像学，认真体会病理形态学特征：如有无原位癌成分，肿瘤分化是否与免疫表型匹配，并结合恰当的免疫组织化学抗体鉴别组合，才能精准识别肿瘤的来源为非乳腺原发。.