Lin Dong-Liang, Ding Li, Shao Shi-Hong, Xin Fang-Jie, Zhang Long-Xiao, Li Guang-Qi, Zhao Peng
Department of Pathology, The Affiliated Hospital of Qingdao University, Qingdao 266003, China.
Medical Affairs Department, The Affiliated Hospital of Qingdao University, Qingdao 266003, China.
Pathol Res Pract. 2022 Oct;238:154079. doi: 10.1016/j.prp.2022.154079. Epub 2022 Aug 15.
Pulmonary bronchiolar adenoma (BA) is a rare lung tumour, it is unclear whether BA can develop into a malignancy. We presented five cases of BA-like tumour with monolayered components. This type of tumour may represent the malignant transformation of BA. Histologically, these tumours showed acinar and lepidic growth patterns. The acinar components were well-differentiated. The glandular tumour cells in these tumours contained cuboidal to columnar cells resembling type II pneumocytes or club (Clara) cells. A small number of mucinous cells were found in two cases. A few scattered ciliated cells were detected in three cases. The ciliated cells only existed in the bilayered components. The basal cells were highlighted by CK5/6 and p40 in a partial region of the tumour rather than in the entire tumour. The glandular tumour cells, including those in the bilayered component, were diffusely positive for TTF-1 and napsin-A. EGFR Exon19 deletions were found in four cases, and BRAF V600E mutation was found in one case. These BA-like tumours have biphasic morphological and molecular characteristics of BA and lung adenocarcinoma, suggesting distal-type BA may develop into a malignancy. More cases should be studied and especially cases with metastasis should be searched to further prove the malignant transformation.
肺细支气管腺瘤（BA）是一种罕见的肺部肿瘤，目前尚不清楚BA是否会发展为恶性肿瘤。我们报告了5例具有单层成分的BA样肿瘤。这种类型的肿瘤可能代表BA的恶性转化。组织学上，这些肿瘤表现为腺泡状和鳞屑状生长模式。腺泡成分分化良好。这些肿瘤中的腺性肿瘤细胞包含类似II型肺细胞或克拉拉（Clara）细胞的立方状至柱状细胞。2例中发现少量黏液细胞。3例中检测到少数散在的纤毛细胞，纤毛细胞仅存在于双层成分中。基底细胞在肿瘤的部分区域而非整个肿瘤中被CK5/6和p40突出显示。包括双层成分中的腺性肿瘤细胞在内，均弥漫性表达TTF-1和napsin-A。4例发现EGFR外显子19缺失，1例发现BRAF V600E突变。这些BA样肿瘤具有BA和肺腺癌的双相形态学和分子特征，提示远端型BA可能发展为恶性肿瘤。应研究更多病例，尤其是搜索有转移的病例以进一步证实恶性转化。
