Kidney cancer is a common malignant tumor of male genitourinary system, and its incidence is increasing year by year, so accurate diagnosis and early treatment are especially important in its prevention and treatment. The diagnosis of kidney cancer mainly relies on imaging, including ultrasound, CT and MRI, etc. Kidney mass aspiration biopsy is an invasive test and is not a routine test. Properly grasping the indications of renal mass aspiration biopsy can provide valuable histological reference results for clinical treatment, while inappropriate aspiration biopsy is not beneficial for diagnosis but can cause unnecessary trauma to patients. In this article, we will discuss the clinical value, indications and new advances of aspiration biopsy of renal masses. Clinical value of renal mass puncture biopsy In 2008, Lane et al. of Cleveland Medical Center, Ohio, reported the results of a systematic evaluation of the English literature on renal mass puncture biopsy published before 2001. In this systematic evaluation, an insufficient amount of tissue obtained by puncture for pathologic diagnosis was defined as a puncture failure, and a failure to match the pathologic diagnosis of the tissue obtained by puncture with that of the surgically resected specimen was defined as an inaccurate puncture. The investigators collected a total of 27 relevant papers including 2474 cases. The results showed that the average rate of false-negative puncture biopsy was 4.4% (0-25%), the average rate of false-positive was 1.2% (0-8.2%), the average rate of puncture failure was 8.9% (0-22%), the average rate of pathological failure was 5.5% (0-36%), and the average accuracy rate of kidney cancer diagnosis was 88.9% (40%-100%). The complication rate of renal mass puncture biopsy was <5%, including bleeding, infection, arteriovenous fistula, and pneumothorax. CT performed after renal puncture revealed perirenal bleeding in 85% to 90% of patients, but only 1% to 2% of patients required blood transfusion. For suprarenal pole tumor, the puncture needle enters through the 11th or 12th rib space, which may damage the pleura or lung and cause pneumothorax, the incidence of which is <0.1%. Tumor puncture tract implantation is relatively rare, with an incidence of <0.01%. The mortality rate of renal puncture biopsy is about 0.031%. Two studies are representative in terms of comparing the clinical diagnostic value of imaging and renal mass puncture biopsy. In 2008, a prospective study published by Dechet et al. at Mayo Medical Center, USA, focused on the diagnostic compliance of CT and renal puncture biopsy for primary renal cancer. The study included 100 patients with renal occupancy who underwent CT before surgery and postoperative 2-stitch ex vivo puncture biopsy of the surgical specimen, with independent blinded diagnosis of CT films and paraffin sections of the puncture biopsy specimen by 2 radiologists and 2 pathologists, respectively. The postoperative pathological results showed that 85 cases were malignant. the sensitivity of the CT readings or puncture biopsies of the four physicians was 70%, 77%, 81%, 83%, and the specificity was 20%, 20%, 60%, 33%, respectively, and the misdiagnosis rate of CT examination or puncture biopsy was 20% and 31%, respectively. In 2004, Sanchez-Ortiz et al. of the M. D. Anderson Cancer Center examined the value of imaging and renal puncture biopsy for the diagnosis of metastatic renal cancer. They reviewed the clinical data of 100 patients with renal occupancy who had a previous history of other malignancies. After comparing the results of renal puncture pathology or tumor resection pathology and diagnostic imaging, the investigators found that the main diagnostic factor was the absence of significant enhancement on CT and MRI, and the chance of detecting metastatic kidney cancer was 86% in those with this factor, and conventional renal puncture did not have significant diagnostic value. If the prognosis of the patient's primary tumor is poor and the kidney occupancy is small, follow-up observation should be chosen. If the prognosis of the primary tumor is better, surgery should be chosen. Because of the high accuracy of imaging diagnosis of renal tumors and the high misdiagnosis rate of renal puncture biopsy, the guidelines for the diagnosis and treatment of renal cancer formulated by several academic groups at home and abroad, including the Chinese Medical Association's Urology Section and the National Comprehensive Cancer Network (NCCN), do not recommend puncture biopsy of renal masses as a routine examination. For smaller renal occupying lesions whose nature is difficult to be determined by imaging, these guidelines mostly recommend kidney unit-preserving surgery to clarify the pathology and achieve treatment at the same time, or regular (1~3 months) follow-up examinations to observe the occupying changes to decide the treatment plan. Indications and contraindications for renal mass aspiration biopsy The indications for renal mass aspiration biopsy mainly include the following categories. 1.When there are serious comorbidities and the risk of surgical operation is high, and it is necessary to decide whether to perform surgery or to follow up and observe, kidney aspiration biopsy can be performed; if the aspiration biopsy does not show any evidence of malignancy, observation and follow-up should be continued. 2. Patients who are to undergo physical ablation of kidney cancer (such as cryo- or radiofrequency ablation) should undergo puncture biopsy to clarify the pathology before treatment. Recent clinical trial treatment studies show that the short-term survival rate of kidney cancer patients treated with physical ablation is still satisfactory, but there is a certain recurrence rate, and the long-term efficacy needs further study. For certain patients with small kidney tumors, elderly or frail, radiofrequency ablation or cryotherapy can be chosen. 3.For patients with inoperable advanced renal tumor, if chemotherapy, targeted therapy or other treatments are required, puncture biopsy can be chosen to obtain pathological results for clear diagnosis before treatment. 4. Patients with suspected lymphoma or leukemia invading kidney, since the main treatment of lymphoma or leukemia is systemic chemotherapy, biopsy can be performed to provide basis for further chemotherapy. The following conditions are not suitable for renal puncture biopsy: patients with isolated kidney, renal insufficiency and anatomical abnormalities; patients with imaging showing infiltrative growth of renal tumor and suspected carcinosarcoma or uroepithelial carcinoma, as carcinosarcoma or uroepithelial carcinoma has a higher possibility of punctal tract implantation. New advances in renal mass puncture biopsy With the improvement of renal puncture techniques and advances in pathological diagnosis, the diagnostic compliance rate of renal mass puncture has been continuously improved. In 2008, Lane et al. summarized seven literature on renal mass puncture published after 2001 (including 362 cases) and found that the average false-negative rate was 0.6%, the average false-positive rate was 0, the average puncture failure rate was 5.2%, the average pathologic failure rate was 3.8%, and the average diagnostic accuracy of renal cancer was 96.0%, with improved diagnostic compliance rates compared with those reported in the literature before 2001 The diagnostic compliance rate has improved compared with the literature before 2001. In recent years, new advances in molecular pathology research have been applied to the pathological diagnosis of renal mass puncture. Researchers from Cornell University reported that the use of immunofluorescence in situ hybridization to detect chromosome 3, 7, 10, 13, and 21 abnormalities improved the diagnostic accuracy from 87% to 94%. The literature reports that carbonic anhydrase Ⅸ can be used as a specific marker for renal clear cell carcinoma, HMB 45 can be used to diagnose fatty kidney malformations, and keratin can differentiate between suspensory cell carcinoma and eosinophilic adenoma. It is believed that as the research related to renal mass puncture biopsy is advanced and the level of pathological diagnosis is improved, the results of renal mass biopsy will provide more useful information for the diagnosis and treatment decision of renal occlusion in the future. As another malignant tumor of the male genitourinary system, the main diagnostic method of prostate cancer is significantly different from that of kidney cancer. (2) More than 90% of prostate malignant tumors are adenocarcinoma and have a single histological type, and the difference between benign and malignant tissues of the prostate is more significant under the microscope; (3) Multiple needle punctures can be performed on the prostate, and the diagnostic compliance rate can reach 90% because of the large number of materials taken, which is conducive to pathological diagnosis, and the chance of hemorrhage caused by puncture is low and the risk is small. In contrast, renal tumors contain subtypes such as clear cell carcinoma, suspicious cell carcinoma, papillary carcinoma and eosinophilic adenoma. Eosinophilic granules can be seen in the cytoplasm of each of these cell types, and the number of tissues obtained by puncture is small, making it difficult to distinguish various subtypes of renal carcinoma from eosinophilic adenoma. The proportion of necrosis occurring in kidney cancer tumors is also higher, which easily prevents pathological diagnosis due to inappropriate sampling locations. In addition, the kidney is rich in blood flow, the perirenal tissue is loose and has potentially large tissue gaps, and the risk of bleeding is higher with the use of coarse needles or multi-point puncture. Due to the high accuracy of prostate biopsy, in principle, clinical prostate puncture should be performed before treatment for patients with proposed prostate cancer, and clinicians choose further treatment, such as hormone therapy, radical prostatectomy or radical radiotherapy, mainly based on the puncture results. However, for patients with renal occupancy, the diagnosis is mainly based on imaging before treatment, and only for a small number of patients, puncture is performed under certain circumstances to help in clinical treatment selection.