[Health Lecture] "Bronchioloma of the lungs" - don't be too nervous

We received such a patient in the pathology department. Aunt Fu, 69 years old, suddenly developed coughing and shortness of breath after activities 3 months ago. She had no symptoms before that. In the past week, the number of coughs has increased significantly. Aunt Fu is a little worried about her condition. She then came to our hospital for a CT scan, and the results showed a mixed density ground glass nodule in the outer basal segment of the left lower lobe. In order to clearly determine whether the nodule is benign or malignant, under the guidance of the surgeon, surgical resection was performed and the nodule was pathologically examined. The pathological diagnosis result was bronchiolar adenoma. Aunt Fu was not sure whether bronchiolar adenoma was benign or malignant, so she came to the pathology department for consultation. In fact, bronchiolar adenoma is a benign tumor, in order to make everyone understand and familiar with it. Today, let's talk to you about bronchiolar adenoma.

Bronchiolar adenoma is a new benign tumor included in the 2021 edition of the WHO Classification of Thoracic Tumors. It is a new type added on the basis of the expansion of ciliary mucinous papilloma. This tumor has only been reported in the past two years. Bronchiolar adenoma is a benign peripheral lung tumor composed of a double layer of bronchiolar subtype epithelium with a continuous basal cell layer, and often occurs in the bronchioles around the lungs. Patients with this tumor usually have no obvious clinical symptoms. Most of them are discovered during physical examinations. A few cases have chest discomfort. The cause of the disease has no obvious relationship with gender or smoking. Physical examination CT examinations often show small lung nodules, and the edges may show ground glass or burr signs, but imaging examinations are difficult to distinguish from lung adenocarcinoma.

The classic bronchiolar adenoma is a solitary nodule with clear boundaries and a two-layer structure, namely basal cells and luminal cells. The presence of the basal cell layer can be confirmed by immunohistochemical staining. However, in actual work, we often encounter partial or even complete disappearance of basal cells, which poses a great challenge to the pathological diagnosis of this lesion, especially for frozen sections and small biopsies. For intraoperative rapid freezing, the quality of frozen sections is not as good as paraffin sections, and the tissue morphology is not ideal. In addition, the lack of intraoperative frozen immunohistochemical markers makes it extremely difficult to diagnose bronchiolar adenomas during intraoperative rapid freezing.

Currently, surgical resection is the preferred treatment for bronchiolar adenoma, which has a good prognosis. I believe that with the continuous summary of the morphological characteristics of bronchiolar adenoma, more pathologists and clinicians will have a better understanding of this lesion. At the same time, I hope that more patients will understand and recognize this lesion, and I also hope that clinical pathologists will have more understanding and tolerance.

About the Author:

Feng Runlin, male, master's student, attending physician of the Department of Pathology, the Second Affiliated Hospital of Kunming Medical University, member of the Popular Science and Health Education Working Committee of the Chinese Medical Education Association, has been engaged in pathological diagnosis in the Department of Pathology for more than 10 years and is good at pathological diagnosis of gastrointestinal tumors and urinary system tumors.