# 肥大（Hypertrophy）

- 器官 / 系统：骨骼肌 / 骨骼肌肉系统（skeletal-muscle / musculoskeletal-system）
- NTP 数据编号：ntp-0593
- 规范 URL：https://www.labsmart.cn/ntp/skeletal-muscle-hypertrophy.html
- 中文图谱总页锚点：https://www.labsmart.cn/ntp-atlas.html#skeletal-muscle-hypertrophy
- 原始出处：https://ntp.niehs.nih.gov/atlas/nnl/musculoskeletal-system/skeletal-muscle/Hypertrophy
- 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
骨骼肌肥大（skeletal muscle hypertrophy）在组织学上的特征是肌纤维直径增大。

## 病变描述（中文）
骨骼肌肥大（skeletal muscle hypertrophy）在组织学上的特征是肌纤维直径增大。这在组织学上有时难以检出。肥大由工作负荷增加所致，既可为局灶性（focal），即作为周围肌肉丧失或萎缩后的代偿性反应，也可范围更广，作为运动需求增加的生理性反应。此外，弥漫性（diffuse）肥大还可因长期暴露于过量生长因子（如生长激素或促生长性外源化学物）而发生。因肌病性或神经病性疾患而发生代偿性肥大的肌纤维，其直径可达发生生理性肥大纤维的两倍。这些纤维常为异常，可含一个或多个内移细胞核，发生纵向分裂（Figure 1、Figure 2），和/或表现出奇异的细胞构筑改变，如裂隙形成和漩涡状排列。在这些情况下，肥大的单个肌纤维常散在分布于萎缩的肌纤维之间。

## 诊断与分级建议（NTP 共识，中文）
凡存在肥大时，均应作出诊断并分级。当肥大发生于萎缩区域内时，不应单独诊断，除非其严重程度足以支持单独诊断。

## 英文原文 · Comment
Skeletal muscle hypertrophy is characterized histologically by an increase in myofiber diameter. This can sometimes be difficult to detect histologically. Hypertrophy occurs as a result of increased workload and can occur either focally, as a compensatory reaction following the loss or atrophy of surrounding muscle, or more extensively, as a physiologic response to increased exercise demands. In addition, diffuse hypertrophy can occur in response to prolonged exposure to excessive growth factors, such as growth hormones or growth-promoting xenobiotics. Myofibers undergoing compensatory hypertrophy due to a myopathic or neuropathic disorder can reach diameters up to twice that of fibers that have undergone physiologic hypertrophy. These fibers are often abnormal and can contain one or more internal nuclei, undergo longitudinal splitting ( Figure 1 and Figure 2 ), and/or exhibit bizarre cytoarchitectural alterations, such as clefting and whorling. In these instances, individual hypertrophic myofibers are often interspersed among atrophic ones.

## 英文原文 · Recommendation
Whenever present, hypertrophy should be diagnosed and graded. When hypertrophy occurs within an area of atrophy, it should not be diagnosed separately unless warranted by severity.

## 配图
- https://www.labsmart.cn/ntp-atlas-images/ntp_0546.jpg
- https://www.labsmart.cn/ntp-atlas-images/ntp_0549.jpg

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