Clinicalpathological Study Of Bronchiolar Adenoma

Background:Bronchiolar adenoma is a group of tumors that occur in peripheral bronchioles of the lung,proposed by Chang in 2018.The basis of Chang proposed BA is the Ishikawa’s presentation of ciliated mucoid papillary tumors in 2002.Chang according to the similarity between tumor tissue morphology and immunophenotypic characteristics and mucosal epithelial of proximal bronchioles to distal respiratory bronchioles,the BA were divided into proximal and distal types.CMPT is considered to be a subtype of proximal bronchioloma by Chang.By 2020,Zhang Jie,a scholar,put forward the description of "classical bronchiolar adenoma ",that is,Chang proposed bronchiolar adenoma and " non-classical bronchiolar adenoma ",that is,monolayer bronchiolar adenoma.The relationship between "non-classical bronchiolar adenoma" and "classical bronchiolar adenoma ",scholars Shao Jinchen and Zhang Jiehave studied26 cases of bronchioadenoma.It is believed that classical bronchiolar adenoma,monolayer bronchiolar adenoma and monolayer bronchiolar adenoma-like lesions may reflect the continuous process of malignant transformation of bronchiole epithelial adenoma.The understanding of pathological features and pathological properties of bronchiolar adenoma needs to be further improved.Studies have shown that MUC5 B and MUC5 AC are the main components of mucin in normal airway,MUC5 AC are mainly expressed in epithelial goblet cells on airway surface,MUC5 B mainly in submucosal gland mucus cells.Kenichi Okuda studies have shown that submucosal glandular mucus cells express MUC5 B,but not MUC5 AC,However,in addition to terminal bronchioles,MUC5 B are widely expressed in the superficial epithelium of the whole airway and are mainly expressed in the bronchioles.Clara cell 10 kD protein(CC10)is one of the most abundant proteins expressed in respiratory secretions.it was initially found that CC10 is mainly secreted by clara cells located in the bronchioles,which are columnar / cubic secretory epithelial cells.A later study found that the CC10 is widely expressed in all the mucosal epithelium connected with the outside world,mainly secreted by non-fibrous epithelial columnar mucinous cells.Kenichi Okuda study of normal bronchioles shows that the specific dominant cell types in different regions of the airway can be identified by combining CC10 、MUC5B 、MUC5AC.Objectives: To study the pathological features of bronchiolar adenoma by histomorphology,cell composition and immunohistochemistry,and to investigate whether Chang formulation of proximal and distal types of bronchiolar adenoma is reasonable.Methods: By used immunohistochemical HRP method to detect the expression and distribution of CK5/6、P63、P40、CK7、TTF-1、Napsin-A、KI-67、CC10、OCT4、MUC1、MUC2、MUC4、MUC5AC、MUC5B、MUC6 in tissues,and combined with tissue morphology to understand the histomorphological characteristics of bronchiolar adenoma.Results:1.Case data :39 cases(41 lesions),20 males,19 females,The median age of patients was 60 years(44-77 years);tumor growth site: right lower lobe 21/41,left lower lobe9/41,right upper lobe 2/41,right middle lobe 4/41,left upper lobe 5/41.2.CK5/6、P63、P40 expression: CK5/6、P63、P40 was continuously expressed in basal cells of 37/41 tumors.In 3/41 cases of tumor CK5/6 negative expression was found in the inconspicuous region of basal cells,and P63 and P40 were expressed in different degrees in this area,and one case P40 was negative in the inconspicuous region of basal cells and P63 scattered expression.3.The expression of CC10/MUC5AC/MUC5 B combination: the positive expression rate of CC10+/MUC5AC+/MUC5B+ combination 1was significantly different between group A,B,C and D(the P value was 0.008& 0.05,Pearson R value is-0.446);The positive expression rate of CC10+/MUC5AC-/MUC5B+combination 2 was not significantin group A,B,C and D.The positive expression rate of CC10+/MUC5AC-/MUC5B-combination 3 was significantly different between group A,B,C and D(the P value was 0.023<0.05,Pearson R value is+ 0.445).4.Types of bronchiolar adenoma: A group(mainly papillary duct-like structure,papillary surface and cavity edge mainly composed of ciliated cells and mucinous cells,with continuous basal cells);B group(mainly adenoid structure,cavity edge composed of ciliated cells and mucinous cells,continuous basal cell layer under cavity edge);C group(mainly adenoid or adherent growth,mainly ciliated cells and cubic / columnar cells,basal cell layer under cavity edge);D group(with adherent growth as the main companion adenoid structure,the cavity edge is mainly composed of columnar / cubic cells,and the basal cells are discontinuous under the cavity edge).Conclusion:1.There was no difference between male and female in the incidence of bronchiolar adenoma,most of them occurred in middle-aged and elderly patients,the right lung was more than the left lung,and the lower lobe was more likely to occur.2.The bilayer structure with basal cells is an important basis for the diagnosis of bronchiolar adenoma.It is not reliable to use a single basal cell marker to label basal cells,which requires the combined detection of multiple basal cell markers.3.Bronchiolar adenoma of single-layer luminal surface cells is rare,and the pathological properties need to be further studied.4.As a result,bronchiolar adenoma can be classified into A、B、C、D type four types.