摘要目的：探讨肺胎儿型腺癌（ FACL）的临床病理学特征、诊断、鉴别诊断及分子遗传学特点。方法收集福建省立医院6例FACL，进行组织形态学、免疫组织化学及特殊染色检查，进行了表皮生长因子受体（ EGFR）基因突变检测，并随访患者、复习相关文献，进行综合分析。结果3例女性和3例男性，年龄40～75岁（中位年龄59岁），肿块最大径2.5～6.0 cm（平均3.8 cm）。病理组织学上，6例表现相似，肿瘤由典型的类似胎儿肺小管的腺样结构组成，瘤细胞呈假复层排列，胞质透明或颗粒状，可见核下及核上空泡，分化好的腺腔内可见到桑葚体。免疫组织化学：肿瘤细胞呈甲状腺转录因子1、Napsin A、低相对分子质量细胞角蛋白（CK）阳性（6／6），部分病例高相对分子质量CK （2／6）、突触素（1／6）、嗜铬粒素A（1／6）、CD56（2／6）、EGFR（4／6）阳性。 PAS／PASD染色阳性。 EGFR基因检测显示例4未检测到EGFR基因突变，其余5例均检测到EGFR突变信号。6例均行手术切除，4例予以术后化疗，术后分别随访1～40个月均无复发与转移。结论 FACL属于一种少见的肺癌类型，具有特征性的病理学表现，临床及病理均需与腺泡型腺癌、腺鳞癌、肺母细胞瘤、神经内分泌癌、转移性子宫内膜腺癌等肿瘤相鉴别，治疗以手术切除为主，预后较好。

abstractsObjective To investigate the clinicopathologic features, diagnosis and differential diagnosis, and genetic alterations of fetal adenocarcinoma of lung ( FACL).Methods Six cases of FACL were collected from Fujian Provincial Hospital, the clinicopathologic features and immunophenotype were retrospectively evaluated, PAS/PASD staining and genetic mutation analysis of epidermal growth factor receptor ( EGFR) were performed.Results There were three male and three female patients, aged 40 to 75 years ( median 59 years).Tumor size ranged from 2.5-6.0 cm ( mean 3.8 cm).Histologically, the tumors showed classic glandular structure similar to fetal lung tubules.The neoplastic glands were lined by non-ciliated pseudostratified columnar epithelium with clear or granular cytoplasm.Some cells showed subnuclear or supranuclear vacuoles.Squamoid morules were also noted.Immunohistochemically, the tumor cells were positive for TTF1, Napsin A, CKL, and focally positive for CKH (2/6), synaptophysin (1/6), chromogranin A (1/6), CD56 (2/6), and EGFR (4/6).PAS/PASD staining was positive in the tumor cells.Five cases showed EGFR mutation, one case was of wild type.All six patients underwent surgical resection, and four had chemotherapy.All patients had no evidence of recurrence or metastasis during 1-40 months follow-up period.Conclusions FACL is a rare tumor with low malignant potential and has distinct morphologic feature.Clinically and pathologically, it needs to be differentiated from alveolar adenocarcinoma, adenosquamous carcinoma, pneumoblastoma, and metastatic endometrioid adenocarcinoma.The primary treatment for FACL is complete surgical excision and chemotherapy, with good outcome.