Du Ying, Wang Zheng-Yan, Zheng Zheng, Li Ying-Xue, Wang Xiu-Yu, Du Ran
Department of Pathology, The Affiliated Hospital of Shandong First Medical University (Liaocheng People's Hospital), Liaocheng 252000, Shandong Province, China.
World J Clin Cases. 2022 May 16;10(14):4541-4549. doi: 10.12998/wjcc.v10.i14.4541.
The clinicopathological features, immunohistochemical characteristics, and genetic mutation profile of two unusual cases of distal bronchiolar adenoma are retrospectively analyzed and the relevant literature is reviewed.
Case 1 was a 63-year-old female patient who had a mixed ground-glass nodule, with mild cells in morphology, visible cilia, and bilayer structures in focal areas. Immunohistochemical staining for P63 and cytokeratin (CK)5/6 revealed the lack of a continuous bilayer structure in most areas, and no mutations were found in epidermal growth factor receptor, anaplastic lymphoma kinase, ROS1, Kirsten rat sarcoma, PIK3CA, BRAF, human epidermal growth factor receptor-2 (HER2), RET, and neuroblastoma RAS genes. Case 2 was a 58-year-old female patient who presented with a solid nodule, in which most cells were observed to be medium sized, the nuclear chromatin was pale and homogeneous, local cells had atypia, and cilia were found locally. Immunohistochemical staining for P63 and CK5/6 showed no expression of these proteins in mild cell morphology whereas the heteromorphic cells showed a bilayer structure. The same nine genes as above were analyzed, and HER2 gene mutation was identified.
Some unresolved questions remain to be answered to determine whether the lesion is a benign adenoma or a part of the process of malignant transformation from benign adenoma of the bronchial epithelium. Furthermore, whether lesions with atypical bilayer structures are similar to atypical hyperplastic lesions of the breast remains to be elucidated. Moreover, clarity on whether these lesions can be called atypical bronchiolar adenoma and whether they are invasive precursor lesions is needed. Future studies should examine the diagnostic significance of HER2 gene mutation as a prognostic indicator.
回顾性分析两例罕见的远端细支气管腺瘤的临床病理特征、免疫组化特点及基因突变谱，并复习相关文献。
病例1为一名63岁女性患者，有混合性磨玻璃结节，细胞形态温和，可见纤毛，局部区域有双层结构。P63和细胞角蛋白（CK）5/6免疫组化染色显示大部分区域缺乏连续的双层结构，表皮生长因子受体、间变性淋巴瘤激酶、ROS1、 Kirsten大鼠肉瘤、PIK3CA、BRAF、人表皮生长因子受体-2（HER2）、RET和神经母细胞瘤RAS基因均未发现突变。病例2为一名58岁女性患者，表现为实性结节，其中大部分细胞中等大小，核染色质淡且均匀，局部细胞有异型性，局部可见纤毛。P63和CK5/6免疫组化染色显示，形态温和的细胞中这些蛋白无表达，而异型细胞显示双层结构。对上述相同的9个基因进行分析，发现HER2基因突变。
关于该病变是良性腺瘤还是支气管上皮良性腺瘤恶性转化过程的一部分，仍有一些未解决的问题有待解答。此外，具有非典型双层结构的病变是否与乳腺非典型增生性病变相似仍有待阐明。此外，需要明确这些病变是否可称为非典型细支气管腺瘤以及它们是否为浸润性前驱病变。未来的研究应探讨HER2基因突变作为预后指标的诊断意义。
