# 肺泡上皮增生（Epithelium Alveolus Hyperplasia）

- 器官 / 系统：肺 / 呼吸系统（lung / respiratory-system）
- NTP 数据编号：ntp-0114
- 规范 URL：https://www.labsmart.cn/ntp/lung-epithelium-alveolus-hyperplasia.html
- 中文图谱总页锚点：https://www.labsmart.cn/ntp-atlas.html#lung-epithelium-alveolus-hyperplasia
- 原始出处：https://ntp.niehs.nih.gov/atlas/nnl/respiratory-system/lung/EpitheliumAlveolus-Hyperplasia
- 授权：美国联邦政府作品，公有领域；引用请标注 NTP Nonneoplastic Lesion Atlas
- 适用说明：仅供科研使用，不用于临床诊断

## 一句话结论
肺泡上皮增生（alveolar epithelial hyperplasia）是II型肺泡上皮细胞（type II pneumocyte）的增生，可为原发性（Figure 1、Figure 2、Figure 3、Figure 4）或继发于I型肺泡上皮细胞损伤或炎症（Figure 5）。

## 病变描述（中文）
肺泡上皮增生（alveolar epithelial hyperplasia）是II型肺泡上皮细胞（type II pneumocyte）的增生，可为原发性（Figure 1、Figure 2、Figure 3、Figure 4）或继发于I型肺泡上皮细胞损伤或炎症（Figure 5）。II型肺泡上皮细胞被认为是I型细胞的祖细胞。I型肺泡上皮细胞对氧化剂损伤尤为易感，I型细胞损伤和丢失后常可见II型肺泡上皮细胞增生。当肺泡上皮增生继发于I型肺泡上皮细胞损伤时，通常伴有炎症，而原发性肺泡上皮增生通常不伴有炎症。增生灶的特征为肺泡隔内衬的II型细胞增多、排列紧密、呈立方状。细胞缺乏细胞异型性，罕见核分裂象，胞质空泡可有可无、可明显可不明显。肺泡结构保持完整，增生灶不压迫周围肺实质。这些形态学特征可将增生与腺瘤相鉴别，后者可出现细胞异型性、核分裂象及对邻近组织的压迫，且正常结构扭曲。肺泡巨噬细胞聚集可与原发性增生相关（尽管这种聚集在伴发于肺泡细支气管癌时最为严重）。在某些病例中，肺泡上皮增生灶（原发性或继发性）内部分细胞可具有异型性特征（Figure 6），如核增大、核形状怪异或双核。原发性肺泡上皮增生被认为是肺泡/细支气管腺瘤和癌的前驱病变，尤其当存在细胞异型性特征时。

## 诊断与分级建议（NTP 共识，中文）
肺、上皮、肺泡——增生：只要存在即应作出诊断并给出严重程度分级。当肺泡上皮增生继发于I型肺泡上皮细胞损伤或炎症时，无需单独记录，除非病理学家认为其严重程度值得单独诊断。若未单独诊断，则应在病理描述中将其作为炎症病变的组成部分加以描述。若一项研究中同时存在原发性和继发性肺泡上皮增生，且病理学家认为两者均应诊断，则必须为其指定不同的术语。这可通过添加适当的修饰词来实现，例如“局灶性（focal）”。也就是说，原发性肺泡上皮增生可记录为肺、上皮、肺泡——增生，局灶性，继发性肺泡上皮增生可记录为肺、上皮、肺泡——增生。但必须在病理描述中加以区分。若增生细胞具有明显的异型性特征，诊断中应包含修饰词“非典型性（atypical）”（即肺、上皮、肺泡——增生，非典型性）。相关链接：肺——细胞异型性

## 英文原文 · Comment
Alveolar epithelial hyperplasia is a proliferation of type II pneumocytes and may be primary ( Figure 1 , Figure 2 , Figure 3 , and Figure 4 ) or secondary to type I pneumocyte injury or inflammation ( Figure 5 ). Type II pneumocytes are thought to be the progenitors of type I cells. Type I pneumocytes are especially vulnerable to oxidant injury, and proliferation of type II pneumocytes is often seen following injury and loss of type I cells. When alveolar epithelial hyperplasia is secondary to type I pneumocyte damage, it is usually associated with inflammation, as opposed to primary alveolar epithelial hyperplasia, which is typically not associated with inflammation. Foci of hyperplasia are characterized by an increase in closely spaced, cuboidal type II cells lining alveolar septa. The cells lack cellular atypia, seldom contain mitotic figures, and may or may not have prominent cytoplasmic vacuoles. The alveolar architecture is maintained, and the focus does not compress the surrounding parenchyma. These morphologic characteristics differentiate hyperplasia from adenoma, in which cellular atypia, mitotic figures, and compression of adjacent tissue may be present and the normal architecture is distorted. Accumulations of alveolar macrophages may be associated with primary hyperplasia (although the accumulations are most severe when associated with alveolar bronchiolar carcinomas). In some cases, some of the cells in a focus of alveolar epithelial hyperplasia (primary or secondary) may have features of atypia ( Figure 6 ), such as enlarged or oddly shaped nuclei or binucleation. Primary alveolar epithelial hyperplasia is thought to be the precursor lesion to alveolar/bronchiolar adenomas and carcinomas, especially when there are features of cellular atypia.

## 英文原文 · Recommendation
Lung, Epithelium, Alveolus - Hyperplasia should be diagnosed and given a severity grade whenever present. When the alveolar epithelial hyperplasia is secondary to type I pneumocyte injury or inflammation, it need not be recorded separately unless the pathologist feels that its severity warrants a separate diagnosis. If it is not diagnosed separately, it should be described in the pathology narrative as a component of the inflammatory lesion. If both primary and secondary alveolar epithelial hyperplasia is present in a study, and the pathologist feels that both should be diagnosed, then they must be assigned different terms. This can be accomplished by adding an appropriate modifier, such as "focal." That is, primary alveolar epithelial hyperplasia can be recorded as Lung, Epithelium, Alveolus - Hyperplasia, Focal and secondary alveolar epithelial hyperplasia can be recorded as Lung, Epithelium, Alveolus - Hyperplasia. However, the distinction must be made in the pathology narrative. If the hyperplastic cells have significant features of atypia, the modifier "atypical" should be included in the diagnosis (i.e., Lung, Epithelium, Alveolus - Hyperplasia, Atypical). Related Links: Lung - Atypia, Cellular

## 配图
- https://www.labsmart.cn/ntp-atlas-images/ntp_0858.jpg
- https://www.labsmart.cn/ntp-atlas-images/ntp_0867.jpg

整理：北京天融慧通科技有限责任公司（LabSmart）｜ https://www.labsmart.cn