Objective: To investigate the clinicopathological features, diagnostic criteria and differential diagnosis of primary salivary gland-type duct carcinoma of lung(LSDC). Methods: Two patients with LSDC after surgical resection in Shanghai Pulmonary Hospital from 2020 to 2021 were included; their clinical parameters as well as pathological, immunohistochemical and molecular characteristics of the tumors were analyzed. The relevant literature was also reviewed. Results: Both patients were male, aged 49(case 1) and 64(case 2) years, respectively, and with a history of smoking. The chest computed tomography scan showed both lesions to be centrally located. Gross examination showed the maximum diameters were 16 mm and 35 mm, respectively. The histomorphology of LSDC resembled ductal carcinoma of breast, with intraductal islands of neoplastic cells, which also formed solid nests, papillary, micropapillary and cribriform structures. There was frequent accompanying comedo-like necrosis. The neoplasm cells were markedly heteromorphic, possessing large irregular nuclei with prominent nucleoli, abundant eosinophilic or clear cytoplasm, and mitotic figures were common. Both cases of LSDC were immunoreactive for CKpan, CK7, AR, HER2 staining was (2+) and were negative for TTF1, Napsin A, p40, GATA3, mammaglobin, GCDFP15, SOX10, PSA, P504S, ER, PR, vimentin, S-100, SMA, CK5/6 and p63. The tumor showed double-layer cell structure of the duct, and some basal cells/myoepithelial cells expressed p40 and CK5/6. Case 1 had no gene mutation while case 2 harbored TP53 and KMT2A gene mutation detected by next generation sequencing. Conclusions: LSDC is a very rare and highly aggressive salivary-type malignant tumor. The postoperative diagnosis mainly depends on histopathology and immunohistochemistry, attention should be paid to differential diagnosis to prevent missed diagnosis.
目的： 探讨原发性肺涎腺型导管癌（primary salivary gland-type duct carcinoma of lung，LSDC）的临床病理学特征、诊断及鉴别诊断要点，以提高对该肿瘤的认识。 方法： 收集并分析2020—2021年间同济大学附属上海市肺科医院手术切除后病理确诊的2例LSDC患者的临床特征、病理形态学、免疫组织化学、分子特点并文献复习。 结果： 本组2例LSDC均为男性，年龄分别为49岁（例1）和64岁（例2），均有吸烟史。CT表现及大体检查显示2例均为中央型肿块，最大直径分别为16 mm和35 mm；LSDC组织形态上与乳腺导管癌相似，肿瘤细胞具有在导管内生长的特征，形成实性巢状、乳头状、微乳头状或筛孔状，可见原位癌成分伴有粉刺样坏死；细胞显著异型，核大、不规则，圆形、卵圆形，核仁显著，胞质丰富，嗜酸性或胞质透亮，核分裂象多见；免疫组织化学示肿瘤细胞广谱细胞角蛋白（CKpan）和细胞角蛋白（CK）7阳性，部分表达雄激素受体，HER2呈中等强度表达（2+），甲状腺转录因子1、Napsin A、p40、GATA3、mammaglobin、GCDFP15、SOX10、前列腺特异性抗原、P504S、雌激素受体、孕激素受体、波形蛋白、S-100蛋白、平滑肌肌动蛋白、CK5/6、p63阴性，部分基底细胞/肌上皮细胞表达p40和CK5/6，显示出导管的双层细胞结构；二代测序检测本组LSDC发现例1未见基因异常，例2伴有TP53和KMT2A基因突变。 结论： LSDC是一种十分罕见具有高度侵袭性的涎腺型恶性肿瘤，确诊主要依赖于术后病理组织形态学及免疫组织化学检查，应注意鉴别诊断以防误诊。.