Detection of low-level somatic DNA mutations and minority alleles within a wild-type sample is crucial in fields of medicine,such as cancer,prenatal diagnosis and infectious diseases.Increasing enrichment methods have been developed to study this challenging area.They are typically segregate by their ability to enrich for,and detect,either known or unknown mutations,including COLD-PCR,ice-COLD-PCR,TT-PCR,PNA-mediated PCR,WTB-PCR and digital PCR.In this review,we discuss theoretical principles and relative advantages and disadvantages of these techniques,and put an emphasis on their applications in fields of diseases.

Pulmonary sarcomatoid carcinoma(PSC)is a rare and highly malignant tumor,which includes the follow-ing five pathologic types:pleomorphic carcinoma,spindle cell carcinoma,giant cell carcinoma,carcinosarcoma and pulmonary blastoma.The onset of PSC is occult with non-specific clinical symptoms and signs.The clinical manifestations include irritat-ing cough,bloody sputum,dyspnea,chest pain and so on,which are closely related to the growth and invasion site of the tumor.PSC tends to metastasize early,so most patients are already in local advanced stage or advanced stage with a median survival of 9 months at the time of hospital visit.A patient with primary PSC which led to 90%stenosis in central airway was treated by com-bined method of vascular and tracheoscopic intervention in our respiratory center.This treatment prolonged the patient's survival time and got a satisfactory effect at 19-month follow-up after surgery.Herein we report the case for clinical reference.

Background and objective As a new technique developed in recent years,bronchoscopic interven-tion therapy has the advantages of minimal invasion,high safety and repeatability.The aim of this study is to investigate the clinical characteristics of bronchopleural fistula(BPF)induced by surgeries for lung malignancies or benign diseases and the effect of bronchoscopic intervention therapy for BPF,so as to provide support for prevention and treatment of BPF.Methods Data 64 patients with BPF who were treated by bronchoscopic intervention in Respiratory Disease Cen-ter of Dongzhimen Hospital,Beijing University of Chinese Medicine from June 2020 to September 2023 were collected.Patients with fistula diameter ≤5 mm were underwent submucous injection of macrogol,combined with blocking therapy with N-butyl cyanoacrylate,medical bioprotein glue or silicone prosthesis.Patients with fistula diameter＞5 mm were im-planted with different stents and cardiac occluders.Locations and characteristics of fistulas were summarized,meanwhile,data including Karnofsky performance status(KPS),shortbreath scale(SS),body temperature,pleural drainage volume and white blood cell count before and after operation were observed.Results For all 64 patients,96 anatomic lung resections in-cluding pneumonectomy,lobectomy and segmentectomy were executed and 74 fistulas occurred in 65 fistula locations.The proportion of fistula in the right lung(63.5％)was significantly higher than that in the left(36.5％).Besides,the right inferior lobar bronchial fistula was the most common(40.5％).After operation,KPS was significantly increased,while SS,body tem-perature,pleural drainage volume and white blood cell count were significantly decreased compared to the preoperative values(P＜0.05).By telephone follow-up or readmission during 1 month to 38 months after treament,median survival time was 21 months.33 patients(51.6％)showed complete response,7 patients(10.9％)showed complete clinical response,18 patients(28.1％)showed partial response,and 6 patients(9.4％)showed no response.As a whole,the total effective rate of broncho-scopic intervention for BPF was 90.6％.Conclusion BPF induced by pulmonary surgery can lead to severe symptoms and it is usually life-threating.Bronchoscopic intervention therapy is one of the fast and effective therapeutic methods for BPF.

Pulmonary mixed squamous cell and glandular papilloma(MSCGP)is a subtype of pulmonary papil-loma,which can be classified as central type and peripheral type based on its site of development.The central type is the most common.The clinical manifestations of pulmonary MSCGP are mainly related to the location of the tumor.Surgery is the main treatment for this disease.Bronchoscopic interventional treatment for the MSCGP in the central trachea could receive satis-factory effect.We reported a patient suffered from diffuse tracheal MSCGP who was treated by bronchoscopic interventional treatment in Respiratory Disease Center,Dongzhimen Hospital of Beijing University of Chinese Medicine,aiming to enhance the recognition of the clinical features and provide clinical references for the diagnosis and treatment of such disease.