A patient found a lump in the neck, which was painless and gradually increased in size, and anti-inflammatory treatment was ineffective, so he underwent surgery in a primary hospital and had it removed. For patients, it is necessary to know some general medical knowledge so that they can take less detours. For primary care physicians, diagnosis should be based on scientific and holistic thinking, rather than “treating the head when there is a headache” and “cutting the bag when there is a bag”. For patients with “neck masses” in areas with a high incidence of nasopharyngeal cancer, according to statistics, about 80% of metastatic cancers in the upper neck may have their primary focus in the nasopharynx, so the first physician must think about the possibility of nasopharyngeal cancer, “ask” whether the patient has symptoms such as runny nose, tinnitus, nasal congestion and headache, “do” imaging tests such as CT or MRI, and ask If necessary, nasopharyngeal biopsy pathology should be performed. The nasopharynx has a rich lymphatic network, and the pathological type of nasopharyngeal cancer is mostly low differentiation cancer, so nasopharyngeal cancer cervical lymph node metastasis is very common. According to clinical statistics, about 50% of patients with nasopharyngeal cancer present with “neck mass” as the first symptom, and about 80% of patients with confirmed nasopharyngeal cancer are confirmed to have cervical lymph node metastasis. It is often seen that the metastases in the cervical lymph nodes are very large, while the primary nasopharyngeal lesions are still small and do not cause any obvious symptoms. This is the characteristic of the so-called “downstream” type of nasopharyngeal cancer (of course, in contrast, some patients with nasopharyngeal cancer also show the “upstream” type, which mainly involves bone destruction at the skull base and invasion into the skull, causing headache, double vision, facial numbness and other symptoms). Radiation therapy for nasopharyngeal cancer mainly covers the nasopharynx, skull base, parapharynx and lymphatic drainage area of the neck. According to the statistics of the Cancer Hospital of the Academy of Medical Sciences, lymph node dissection or puncture in the neck of patients with nasopharyngeal cancer may increase the chance of hematogenous metastasis and affect the efficacy of treatment, so patients with nasopharyngeal cancer should be diagnosed by nasopharyngeal biopsy as much as possible and avoid cervical lymph node surgery. Skondalakis, a foreign scholar, has summarized an “80% rule” for the diagnosis of neck masses: 1. For non-thyroidal neck masses, about 20% belong to inflammatory and congenital diseases, while the remaining 80% belong to true tumors. 2. Among patients with true tumors, about 20% belong to benign tumors and 80% are malignant tumors; meanwhile, it is related to gender, about 20% are female and 80% are male. Among the malignant tumors in the neck, 20% are primary in the neck, while most of them are metastases from malignant tumors in other parts of the body (accounting for 80%). 4. 80% of the metastases in the neck originate from the head and face, and 20% from the trunk of the body. It is important to pay attention to the fact that among all metastases in the neck, about 20% of patients have not found the primary lesion even after clinical, imaging, cytological and laboratory examinations, which is called occult primary cancer. For primary tumors of the neck, local radical treatment is reliable. For metastatic cancer of the neck, the primary site must be identified first, and under the condition that the primary site is controlled, lymphatic dissection of the neck can be performed at the same time, which can also achieve better curative effect. For metastatic cancer in the neck with unknown primary site, lymphatic dissection of the neck or radiotherapy and comprehensive treatment can be performed for the metastatic cancer, and the search for the primary lesion can be continued, but such patients have poor curative effect and poor prognosis.