Patient: Back pain for more than six months, ECT examination revealed many black spots, and the doctor said it was multiple bone destruction. Began inpatient examination at Sanmenxia Yellow River Hospital for one week to rule out multiple myeloma and suspect bone metastases. As a result, no primary lesion was found. Later we were transferred to a cancer hospital for one month, and the results were the same, ruling out multiple myeloma and suspecting bone metastases. As a result, no primary lesion was found. It has been one week since the operation, and only 50ml of urine is produced every day (200ml of medicine is flushed every day, 250ml comes out, in the drainage bag, the left kidney is normal, and the urine is normal) with bleeding. The doctor suspected that there was a tumor at the end of the ureter. Laboratory and test results: The tests done were: blood tests to check for multiple myeloma and bone marrow aspiration, etc. were excluded. The tests done to check bone metastases are: tumor marker tests (blood) CT of lung, double-stage enhanced CT of upper abdomen, CT of pelvis, CT of both kidneys, ultrasound of both kidneys, ureter and prostate many times, etc. Test result: right hydronephrosis. There is also hydronephrosis drainage. Zhao Hui, Department of Medical Oncology, Shanghai Sixth People’s Hospital: You can check the MRI of the urinary tract. if you want to clarify the benign and malignant nature of the disease, there is also a simpler way, you should have checked the CT of the ECT concentration site and choose the site of osteolytic lesion under CT guidance to do bone puncture, which can often get more accurate pathological results. The gold standard for the diagnosis of bone metastasis is definitely the diagnosis of cell or pathology. However, if a patient with a history of malignant tumor has imaging evidence such as ECT CT, and 2 or more senior physicians with the same opinion, it can also be used as a clinical diagnosis. Patient: Thank you very much! I will let the doctor do MRI today . I am still waiting for the immunohistochemistry results, and I will know the results in two days. I also heard from other doctors that small cell carcinoma is mostly found in the lungs, but we have also checked the lungs and found nothing. Thank you. Patient: Dr. Zhao: Hello! I got the immunohistochemistry results today and there are only two words: metastatic cancer and poor differentiation. Zhao Hui, Department of Medical Oncology, Shanghai Sixth People’s Hospital: About 17% of patients have metastatic tumors with unknown primary lesions, and the pathological diagnosis of poorly differentiated tumors is often similar to that of small cell carcinoma, so if the primary lesion is not found, the metastatic bone malignant tumor is already at stage IV and surgery is not possible.