Gao Feng, Zang Lijuan, He Jin, Xu Weiqing
Department of Pathology, Shanghai General Hospital,Shanghai Jiao Tong University School of Medicine, Shanghai, 200080, People's Republic of China.
Onco Targets Ther. 2021 Mar 18;14:1997-2002. doi: 10.2147/OTT.S296400. eCollection 2021.
Primary tracheal adenoid cystic carcinoma (ACC) is a rare and heterogeneous group of neoplasms arising from the respiratory tract. The solid variant of ACC is a histologically distinct subtype with an unfavorable clinical course. We report on a case of tracheal ACC with immunohistochemical and molecular analysis together with a review of the literature.
We observed a case in which a 31-year-old male presented with a neoplasm bulging into the lumen and caused symptoms of tracheal obstruction and even hemoptysis. Cytological smears of an endobronchial fine needle aspiration revealed aggregates of basaloid cells with small to medium size, scant cytoplasm, and evenly hyperchromatic nuclei. Histologically, the tumor is characterized by a predominant compact sheet-like and nested pattern of rounded basaloid cells. Immunohistochemically, the tumor was diffusely positive for CK and CD117. CK7 and CK5/6 were focally positive in the genuine glandular structures. P63 was completely negative in the majority of neoplastic cells. Fluorescence in situ hybridization analysis revealed MYB gene rearrangement.
The solid variant of ACC from trachea is rare and hence poses diagnostic difficulty. Computed tomography (CT) scan and bronchoscopy help assess the extent of the disease. Histological features combined with immunophenotypic and molecular analysis aid in distinguishing this uncommon type from other round cell neoplasms. The accurate diagnosis can help expedite treatment of this highly aggressive tumor.
原发性气管腺样囊性癌（ACC）是一种罕见且异质性的肿瘤，起源于呼吸道。ACC的实性变体是一种组织学上独特的亚型，临床病程不佳。我们报告一例气管ACC病例，进行了免疫组化和分子分析，并对文献进行了综述。
我们观察到一例31岁男性患者，其肿瘤向管腔内突出，导致气管阻塞症状甚至咯血。支气管内细针穿刺的细胞学涂片显示，基底样细胞聚集，细胞小至中等大小，胞质稀少，核呈均匀的深染。组织学上，肿瘤的特征是主要为紧密的片状和巢状排列的圆形基底样细胞。免疫组化显示，肿瘤CK和CD117弥漫性阳性。CK7和CK5/6在真正的腺管结构中局灶性阳性。大多数肿瘤细胞中P63完全阴性。荧光原位杂交分析显示MYB基因重排。
气管ACC的实性变体罕见，因此诊断困难。计算机断层扫描（CT）和支气管镜检查有助于评估疾病范围。组织学特征结合免疫表型和分子分析有助于将这种罕见类型与其他圆形细胞瘤相鉴别。准确诊断有助于加快对这种高度侵袭性肿瘤的治疗。
