Adenocarcinoma is a malignant tumor that occurs in the epithelium of the salivary gland and has a variable structure, but without the residual component of pleomorphic adenoma. Adenocarcinoma accounts for 9 percent of salivary gland epithelial tumors and is one of the more malignant types of salivary gland malignancies. We have all heard of breast cancer and pancreatic cancer, but do you know about adenocarcinoma? I. What is adenocarcinoma? Since adenocarcinoma is infiltrative in growth, it should be extensively resected. The metastasis rate of adenocarcinoma lymph nodes is high, which can be as high as 36% to 47%. Radical or selective cervical lymph node dissection should be performed along with resection of the primary site. For the management of the facial nerve, it is necessary to sacrifice the facial nerve for complete resection of the tumor, regardless of whether facial nerve paralysis will occur. Surgery should be coupled with frozen histopathological sections to examine the surgical margins for residual tumor cells. Adenocarcinoma is not sensitive to radiation and should not be treated with radiation alone, but postoperative adjuvant therapy may also improve the efficacy. For those who are not suitable for surgery in late stage, palliative radiotherapy has certain control effect but cannot achieve the purpose of radical cure. Adjuvant chemotherapy can also be used after surgery. Clinical manifestations Adenocarcinoma mainly occurs in the parotid gland and small salivary glands of the palate, mostly in middle-aged and elderly patients. Adenocarcinoma grows faster and has a shorter course. The tumor grows infiltratively and is often poorly bounded with normal tissues, with poor mobility or even fixed. In advanced stage, it may invade the skin, muscle, nerve and bone tissue, which may cause ulceration on the surface of the tumor, pain and difficulty in opening the mouth. If it occurs in parotid gland, it can be fixed with external auditory canal, temporal bone and mandible, and if it occurs in submaxillary gland, it can be fixed with floor of mouth and mandible. Pathological changes 1. Gross morphology: the tumor is round or ovoid, most of them are not enveloped, but incomplete. The texture is medium hard and the cut surface is grayish white. 2. Microscopic examination: tumor cells have obvious heterogeneity and different structures. Some of them are solid masses or small cords, some of them can be seen as glandular cavities, and some of them are arranged into tubular or glandular-like structures. It is generally believed that those with glandular lumen-like structures have a higher degree of differentiation and a lower degree of malignancy. The number of connective tissues between small cords and small masses is variable, and those with more are similar to hard carcinoma; those with less interstitium and more cancer cells can be called soft carcinoma. 3.Biological characteristics: Adenocarcinoma has highly infiltrative and destructive growth characteristics. Adenocarcinoma easily invades blood vessels and lymphatic vessels, and there are more blood and lymphatic metastases.