增生Hyperplasia · 哈氏腺 · 特殊感觉系统 · NTP ntp-0316

Comment：
Harderian gland hyperplasia ( Figure 1 , Figure 2 , Figure 3 , and Figure 4 ) is characterized as a well-demarcated but noncompressive focal area in which alveoli are lined by increased numbers of large cells with slightly different tinctorial quality than surrounding normal cells. Nuclei are often similar to those of normal cells, but in some cases, the nuclei may be enlarged ( Figure 1 and Figure 2 ). The increased cell numbers can result in crowding and multiple cell layers ( Figure 3 and Figure 4 ), and even formation of small papillary projections. The absence of compression or marked nuclear pleomorphism can help distinguish Harderian gland hyperplasia from adenoma. Harderian gland hyperplasia may occur as a reactive sequela to degeneration and inflammation but can also be a primary toxic effect and precursor to Harderian gland neoplasia.

Recommendation：
Harderian gland hyperplasia should be diagnosed and assigned a severity grade. Whether the hyperplasia is considered a primary effect or a secondary reactive change should be noted in the narrative, especially if there are treatment-related differences in incidence and/or severity.