嗅上皮呼吸上皮化生Olfactory Epithelium Metaplasia Respiratory · 鼻 · 呼吸系统 · NTP ntp-0131

Comment：
Respiratory metaplasia is defined as the replacement of olfactory epithelium with a ciliated, respiratory epithelium ( Figure 1 , Figure 2 , Figure 3 , and Figure 4 ). The presence of respiratory metaplasia implies that loss of olfactory epithelium has occurred through necrosis or atrophy. Treatment-related atrophy of olfactory nerves beneath the affected olfactory epithelium can occur. Small focal, unilateral areas of respiratory metaplasia can sometimes be seen in control animals ( Figure 4 ).

Recommendation：
Respiratory metaplasia should be diagnosed and graded. Small, focal lesions seen in control animals should be diagnosed when the nose is an obvious or potential target organ. Necrosis or atrophy associated with respiratory metaplasia of the olfactory epithelium should not be diagnosed unless it is clearly a separate process and atrophic or necrotic areas are present elsewhere in the olfactory epithelium. It is common for respiratory metaplasia to be present in the epithelium of the Bowman’s glands beneath the affected olfactory epithelium. This can be described in the narrative and not diagnosed separately unless warranted by its prominence or severity (see Nose - Olfactory Epithelium, Glands - Metaplasia ). Atrophy of the olfactory nerves should also be described in the narrative, unless its severity warrants a separate diagnosis. Related Links: Nose - Olfactory Epithelium, Glands - Metaplasia