Some patients have been suffering from neck and shoulder pain on the right side for more than half a year, and have been diagnosed as “frozen shoulder” and “cervical spondylosis” in the orthopedic department of the hospital for many times, but they have not seen any improvement after a period of treatment. Later, a chest X-ray was taken for other reasons and found that there was a shadow on the right apical lung, and further CT examination revealed that the shadow had eroded the first rib and invaded and encircled the large blood vessels at the exit of the thorax. This is a typical case of carcinoma of the pulmonary apex. Apical lung cancer (also called superior pulmonary sulcus tumor, pancoast tumor) is a kind of lung cancer, because of the special growth location, which is at the top of the chest, the space there is narrow, and there are blood vessels and nerves passing through it, so the tumor is very easy to invade the blood vessels, nerves and chest wall, causing related symptoms, such as neck and shoulder pain, shoulder and arm pain or radiating pain and numbness of the affected upper limbs, similar to frozen shoulder or cervical spondylosis, etc., plus the patient Most of the patients are over 50 years old, and most of them think they are suffering from frozen shoulder or cervical spondylosis and go to orthopedic outpatient clinics. Since local radiographs rarely include bilateral apical lung, lack of contrast, atypical abnormalities in the apical lung are easily overlooked, thus delaying the correct diagnosis and treatment of the disease. The detection and diagnosis of apical lung cancer mainly rely on imaging examinations, such as chest X-ray and CT, etc. In typical cases, spherical shadows of the apical lung can be seen, which are easy to detect, while in some cases, only local thickening of the pleural apex can be seen, which requires further CT examination to detect the abnormality. Pathological biopsy is needed to confirm the final diagnosis. Most of the pathological types of carcinoma of the lung apical region are squamous carcinoma with local invasion and late occurrence of distant metastasis. Therefore, even though the tumor has invaded blood vessels, nerves, ribs and other structures, as long as the local area can be completely resected, satisfactory results can be obtained after surgery, especially for patients with obvious pain in the shoulder and arm before surgery, the local pain can be well controlled after complete resection and the quality of life is satisfactory. In addition, some of the carcinomas in the apical lung are adenocarcinoma and some are small cell carcinoma. Because small cell carcinoma has special biological characteristics and different treatment principles, preoperative pathological diagnosis should be clarified as much as possible for different treatment plans. Since most of the apical lung cancers are found to have obvious invasion and are difficult to be resected surgically, it is recommended to add local radiotherapy of 3000-4000 cGy before surgery for cases with serious invasion to shrink the tumor and occlude the blood vessels, so as to reduce the scope and difficulty of surgical resection and increase the completeness of resection. Depending on the postoperative pathology, postoperative radiotherapy and/or chemotherapy is added. Thus, although the most common causes of neck and shoulder pain are common orthopedic diseases such as frozen shoulder and cervical spondylosis, we should not be too careful and need to be alert to the hidden “killer” of lung cancer.