This morphological and immunohistochemical study demonstrates that tumors currently known as “middle ear adenomas” are truly well-differentiated epithelial neuroendocrine tumors (NETs) composed of cells comparable to normal intestinal L cells, and therefore, these tumors resemble hindgut NETs. These tumors show consistent expression of glucagon, pancreatic polypeptide, PYY, and the transcription factor SATB2, as well as generic neuroendocrine markers and keratins. The same L cell markers are expressed by cells within the normal middle ear epithelium. These markers define a valuable immunohistochemical profile that can be used for differential diagnosis of middle ear neoplasms, particularly in distinguishing epithelial NETs from paragangliomas. The discovery of neuroendocrine cells expressing the same markers in non-neoplastic middle ear mucosa opens new areas of investigation into the physiology of the normal middle ear and the pathophysiology of middle ear disorders.

这项形态学和免疫组织化学研究表明，目前被称为“中耳腺瘤”的肿瘤是真正分化良好的上皮神经内分泌肿瘤 (NET)，由与正常肠 L 细胞相当的细胞组成，因此，这些肿瘤类似于后肠 NET。这些肿瘤显示出胰高血糖素、胰多肽、PYY 和转录因子 SATB2 以及通用神经内分泌标志物和角蛋白的一致表达。相同的 L 细胞标志物由正常中耳上皮内的细胞表达。这些标志物定义了一个有价值的免疫组织化学特征，可用于鉴别诊断中耳肿瘤，特别是区分上皮 NET 和副神经节瘤。