Fine-needle aspiration technique under endoscopic ultrasound guidance:A technical approach for RNA profiling of pancreatic neoplasms

BACKGROUND Early diagnosis of pancreatic ductal adenocarcinoma(PDAC)has been a longstanding challenge.The prognosis of patients with PDAC depends on the stage at diagnosis.It is necessary to identify biomarkers for the detection and differentiation of pancreatic tumors and optimize PDAC sample preparation procedures for DNA and RNA analysis.Most molecular studies are done using paraffin-embedded blocks;however,the integrity of DNA and RNA is often compromised in this format.Moreover,RNA isolated from human pancreatic tissue samples is generally of low quality,in part,because of the high concentration of endogenous pancreatic RNAse activity present.AIM To assess the potential of endoscopic ultrasound-guided fine-needle aspiration(EUS-FNA)to obtain specimens from pancreatic neoplasms for subsequent RNA molecular profiling,including next-generation sequencing(NGS).METHODS Thirty-four EUS-FNA samples were included in this study:PDAC(n=15),chronic pancreatitis(n=5),pancreatic cysts(n=14),mucinous cysts(mucinous cystic neoplasia/intraductal papillary mucinous neoplasia)n=7,serous cystic neoplasms n=5,and pseudocysts n=2.Cyst material consisted of cyst fluid and cyst wall samples obtained by through-the-needle biopsy(TTNB).Samples were stored at -80℃ until analysis.RNA purity(A260/230,A260/280 ratios),concentration,and integrity(RIN)were assessed.Real-time polymerase chain reaction was conducted on all samples,and small RNA libraries were prepared from solid mass samples.RESULTS RNA was successfully extracted from 29/34(85%)EUS-FNA samples:100% pancreatic adenocarcinoma samples,100% chronic pancreatitis samples,70% pancreatic fluid cyst samples,and 50%TTNB samples.The relative expression of GAPDH and HPRT were obtained for all successfully extracted RNA samples(n=29)including lowquality RNA specimens.Low concentration and nonoptimal RIN values(no less than 3)of RNA extracted from EUS-FNA samples did not prevent NGS library preparation.The suitability of cyst fluid samples for RNA profiling varied.The quality of RNA extracted from mucinous cyst fluid had a median RIN of 7.7(5.0-8.2),which was compatible with that from solid neoplasms[6.2(0-7.8)],whereas the quality of the RNA extracted from all fluids of serous cystic neoplasms and TTNB samples had a RIN of 0.CONCLUSION The results demonstrate the high potential of EUS-FNA material for RNA profiling of various pancreatic lesions,including low-quality RNA specimens.

Slow-pull and different conventional suction techniques in endoscopic ultrasound-guided fine-needle aspiration of pancreatic solid lesions using 22-gauge needles

AIM To evaluate the cytological diagnostic capacity and sample quality of the slow-pull technique and compare them with different suction techniques.METHODS From July 2010 to December 2015, 102 patients with pancreatic solid lesions who underwent endoscopic ultrasound-guided fine-needle aspiration(EUS-FNA) with 22-gauge needles were retrospectively evaluated. EUS-FNA diagnosis was based on a cytological examination, and final diagnosis was based on a comprehensive standard of cytological diagnosis, surgical pathology and clinical or imaging follow-up. Cytological specimens were characterized for cellularity and blood contamination. The cytological diagnostic capacity and sample quality of the slow-pull technique and suction techniques with 5-m L/10-m L/20-m L syringes were analyzed.RESULTS Of all of the EUS-FNA procedures, the slow-pull technique and suction techniques with 5-m L/10-m L/20-m L syringes were used in 31, 19, 34 and 18 procedures, respectively. There were significant differences between these four suction techniques in terms of cytological diagnostic accuracy(90.3% vs 63.2% vs 58.8% vs 55.6%, P = 0.019), sensitivity(88.2% vs 41.7% vs 40.0% vs 36.4%, P = 0.009) and blood contamination(score ≥ 2 for 29.0% vs 52.6% vs 70.6% vs 72.2%, P = 0.003). The accuracy and sensitivity of the slow-pull technique were significantly higher than those of the suction techniques using 5-m L(P = 0.03, P = 0.014), 10-m L(P = 0.005; P = 0.006) and 20-mL syringes(P = 0.01, P = 0.01). Blood contamination was significantly lower in the slow-pull technique than in the suction techniques with 10-m L(P = 0.001) and 20-mL syringes(P = 0.007).CONCLUSION The slow-pull technique may increase the cytological diagnostic accuracy and sensitivity with slight blood contamination during EUS-FNA when using 22-gauge needles for solid pancreatic masses.

Influence of the safety and diagnostic accuracy of preoperative endoscopic ultrasound-guided fine-needle aspiration for resectable pancreatic cancer on clinical performance

AIM: To evaluate the safety and diagnostic accuracy of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in a cohort of pancreatic cancer patients.

Endoscopic ultrasound-guided fine-needle aspiration biopsy-Recent topics and technical tips

Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA) is a useful procedure that enables reliable pathological diagnoses of pancreatobiliary diseases, subepithelial lesions, and swollen lymph nodes. In recent years, a pathological diagnosis based on EUS-FNA has made it possible to provide accurate treatment methods not only in these fields, but also in respiratory organs and otorhinolaryngology. This review discusses the latest topics pertaining to EUS-FNA as well as procedural tips.

Endoscopic ultrasound-guided tissue acquisition for the diagnosis of focal liver lesion

In patients with liver tumors,the histopathology examination can assist in diagnosis,staging,prognosis,and therapeutic management strategy.Endoscopic ultrasound(EUS)-guided tissue acquisition using fine needle aspiration(FNA)or more newly fine needle biopsy(FNB)is a well-developed technique in order to evaluate and differentiate the liver masses.The goal of the EUS-FNA or EUS-FNB is to provide an accurate sample for a histopathology examination.Therefore,malignant tumors such as hepatocarcinoma,cholangiocarcinoma and liver metastasis or benign tumors such as liver adenoma,focal hyperplastic nodular tumors and cystic lesions can be accurately diagnosed using EUS-guided tissue acquisition.EUS-FNB using 19 or 22 Ga needle provide longer samples and a higher diagnostic accuracy in patients with liver masses when compared with EUS-FNA.Few data are available on the diagnostic accuracy of EUS-FNB when compared with percutaneously,ultrasound,computer tomography or transjugulary-guided liver biopsies.This review will discuss the EUS-guided tissue acquisition options in patients with liver tumors and its efficacy and safety in providing accurate samples.The results of the last studies comparing EUS-guided liver biopsy with other conventional techniques are presented.The EUS-guided tissue acquisition using FNB can be a suitable technique in suspected liver lesions in order to provide an accurate histopathology diagnosis,especially for those who require endoscopy.

Accuracy of endoscopic ultrasound-guided needle aspiration specimens for molecular diagnosis of non-small-cell lung carcinoma

BACKGROUND Endoscopic ultrasonography-guided fine-needle aspiration(EUS-FNA)and endobronchial ultrasound-guided transbronchial needle aspiration(EBUS-TBNA)are highly sensitive for diagnosing and staging lung cancer.In recent years,targeted therapy has shown great significance in the treatment of non-small cell lung carcinoma(NSCLC).Using these minimally invasive techniques to obtain specimens for molecular testing will provide patients with a more convenient diagnostic approach.AIM To evaluate the feasibility and accuracy of tissue samples obtained using EUSFNA and EBUS-TBNA for molecular diagnosis of NSCLC.METHODS A total of 83 patients with NSCLC underwent molecular testing using tissues obtained from EUS-FNA or EBUS-TBNA at the Tianjin Medical University Cancer Hospital from January 2017 to June 2019.All enrolled patients underwent chest computed tomography or positron emission tomography/computed tomography prior to puncture.We detected abnormal expression of EGFR,KRAS,MET,HER2,ROS1 and anaplastic lymphoma kinase protein.Two patients failed to complete molecular testing due to insufficient tumor tissue.The clinical features,puncture records,molecular testing results and targeted treatment in the remaining 81 patients were summarized.RESULTS In a total of 99 tissue samples obtained from 83 patients,molecular testing was successfully completed in 93 samples with a sample adequacy ratio of 93.9%(93/99).Biopsy samples from two patients failed to provide test results due to insufficient tumor tissue.In the remaining 81 patients,62 cases(76.5%)were found to have adenocarcinoma,11 cases(13.6%)had squamous cell carcinoma,3 cases(3.7%)had adenosquamous carcinoma and 5 cases(6.2%)had NSCLC-not otherwise specified.The results of molecular testing showed EGFR mutations in 21 cases(25.9%),KRAS mutations in 9 cases(11.1%),ROS-1 rearrangement in 1 case(1.2%)and anaplastic lymphoma kinase-positive in 5 cases(6.2%).Twentyfour patients with positive results received targeted therapy.The total effectiveness rate of targeted therapy was 66.7%(16/24),and the disease control rate was 83.3%(20/24).CONCLUSION Tissue samples obtained by EUS-FNA or EBUS-TBNA are feasible for the molecular diagnosis of NSCLC and can provide reliable evidence for clinical diagnosis and treatment.

Endoscopic Ultrasound-Guided Fine Needle Aspiration Cytology of Gastrointestinal Tract Tumors and Related Organs: Predictive Factors for Accurate Cytopathological Diagnosis

Background: Endoscopic ultrasonography (EUS) is well-established, highly accurate clinical diagnostic test for detection and staging of gastrointestinal tract lesions and related organs. The addition of endoscopic guided fine needle aspiration cytology (EUS-FNAC) has improved the performance characteristics of EUS. Aim: Evaluate the validity of EUS-FNAC in diagnosis of gastrointestinal tract lesions and related organs and assess predictive factors for an accurate EUS-FNAC diagnosis. Methods: Our study included cytological sampling from one hundred sixty-six lesions obtained from gastrointestinal tract and related organs. Factors affecting EUS-FNA accuracy were analyzed. The histopathological results or clinical follow-up were used as the gold standard method. Results: Samples were obtained from: pancreatic masses (n = 80), gastric masses (n = 34), lymph nodes (n = 22), hepatobiliary masses (n = 18) and rectal masses (n = 2). Statistical analysis of sensitivity, specificity, Positive Predictive Value, Negative Predictive Value, and diagnostic accuracy of EUS alone was 80.4%, 51.6%, 75.8%, 76.2% and 75.9% respectively. The sensitivity, specificity, positive predictive value and negative predictive value of EUS-FNAC are 78.8%, 96.8%, 97.6% and 73.2% respectively. Addition of FNAC to EUS improved diagnostic accuracy to 85.5%. Positive statistical association was present between cytological adequacy and adequate cell block preparations, larger lesion size, presence of rapid on site evaluation (ROSE) and obtaining at least two passes from target lesion. Conclusions: EUS is valuable diagnostic and cost effective tool for gastrointestinal tract lesions and related organs when combined with FNAC.

Early endoscopic management of an infected acute necrotic collection misdiagnosed as a pancreatic pseudocyst: A case report

BACKGROUND Infected acute necrotic collection(ANC)is a fatal complication of acute pancre-atitis with substantial morbidity and mortality.Drainage plays an exceedingly important role as the first step in invasive intervention for infected necrosis;however,there is great controversy about the optimal drainage time,and better treatment should be explored.CASE SUMMARY We report the case of a 43-year-old man who was admitted to the hospital with severe intake reduction due to early satiety 2 wk after treatment for acute pancre-atitis;conservative treatment was ineffective,and a pancreatic pseudocyst was suspected on contrast-enhanced computed tomography(CT).Endoscopic ultra-sonography(EUS)suggested hyperechoic necrotic tissue within the cyst cavity.The wall was not completely mature,and the culture of the puncture fluid was positive for A-haemolytic Streptococcus.Thus,the final diagnosis of ANC in-fection was made.The necrotic collection was not walled off and contained many solid components;therefore,the patient underwent EUS-guided aspiration and lavage.Two weeks after the collection was completely encapsulated,pancreatic duct stent drainage via endoscopic retrograde cholangiopancreatography(ERCP)was performed,and the patient was subsequently successfully discharged.On repeat CT,the pancreatic cysts had almost disappeared during the 6-month fo-llow-up period after surgery.CONCLUSION Early EUS-guided aspiration and lavage combined with late ERCP catheter drainage may be effective methods for intervention in infected ANCs.

Overlooked risk for needle tract seeding following endoscopic ultrasound-guided minimally invasive tissue acquisition

Endoscopic ultrasound-guided minimally invasive tissue acquisition can be performed by two approaches as follows: Endoscopic ultrasound-guided fineneedle aspiration(EUS-FNA) and endoscopic ultrasound-guided fine-needle biopsy(EUS-FNB). These have been evolved into leading approaches and widely used for the histological diagnosis of tumors in the gastrointestinal tract and adjacent organs. However, the role of EUS-FNA and EUS-FNB in disease diagnosis and evaluation remains controversial. Although the incidence of surgery-associated complications remains low, the consequences of needle tract seeding can be serious or even life-threatening. Recently, increasing case reports of needle tract seeding are emerging, especially caused by EUS-FNA. This complication needs serious consideration. In the present work, we integrated these case reports and the related literature, and summarized the relevant cases and technical characteristics of needle tract seeding caused by EUS-FNA and EUSFNB. Collectively, our findings provided valuable insights into the prevention and reduction of such serious complication.

Endoscopic ultrasound-guided through-the-needle microforceps biopsy and needle-based confocal laser-endomicroscopy increase detection of potentially malignant pancreatic cystic lesions:A single-center study

BACKGROUND Currently,there is insufficient data about the accuracy in the diagnosing of pancreatic cystic lesions(PCLs),especially with novel endoscopic techniques such as with direct intracystic micro-forceps biopsy(mFB)and needle-based confocal laser-endomicroscopy(nCLE).AIM To compare the accuracy of endoscopic ultrasound(EUS)and associated techniques for the detection of potentially malignant PCLs:EUS-guided fine needle aspiration(EUS-FNA),contrast-enhanced EUS(CE-EUS),EUS-guided fiberoptic probe cystoscopy(cystoscopy),mFB,and nCLE.METHODS This was a single-center,retrospective study.We identified patients who had undergone EUS,with or without additional diagnostic techniques,and had been diagnosed with PCLs.We determined agreement among malignancy after 24-mo follow-up findings with detection of potentially malignant PCLs via the EUSguided techniques and/or EUS-guided biopsy when available(EUS malignancy detection).RESULTS A total of 129 patients were included, with EUS performed alone in 47/129. In 82/129 patients,EUS procedures were performed with additional EUS-FNA (21/82), CE-EUS (20/82), cystoscopy(27/82), mFB (36/82), nCLE (44/82). Agreement between EUS malignancy detection and the 24-mo follow-up findings was higher when associated with additional diagnostic techniques thanEUS alone [62/82 (75.6%) vs 8/47 (17%);OR 4.35, 95%CI: 2.70-7.37;P < 0.001]. The highestmalignancy detection accuracy was reached when nCLE and direct intracystic mFB were bothperformed, with a sensitivity, specificity, positive predictive value, negative predictive value andobserved agreement of 100%, 89.4%, 77.8%, 100% and 92.3%, respectively (P < 0.001 comparedwith EUS-alone).CONCLUSIONThe combined use of EUS-guided mFB and nCLE improves detection of potentially malignantPCLs compared with EUS-alone, EUS-FNA, CE-EUS or cystoscopy.

Endoscopic ultrasound-guided fiducial marker placement for neoadjuvant chemoradiation therapy for resectable pancreatic cancer

BACKGROUND Preoperative neoadjuvant chemoradiation therapy(NACRT)is applied for resectable pancreatic cancer(RPC).To maximize the efficacy of NACRT,it is essential to ensure the accurate placement of fiducial markers for image-guided radiation.However,no standard method for delivering fiducial markers has been established to date,and the nature of RPC during NACRT remains unclear.AIM To determine the feasibility,safety and benefits of endoscopic ultrasound-guided(EUS)fiducial marker placement in patients with RPC.METHODS This was a prospective case series of 29 patients(mean age,67.5 years;62.1%male)with RPC referred to our facility for NACRT.Under EUS guidance,a single gold marker was placed into the tumor using either a 19-or 22-gauge fine-needle aspiration needle.The differences in daily marker positioning were measured by comparing simulation computed tomography and treatment computed tomography.RESULTS In all 29 patients(100%)who underwent EUS fiducial marker placement,fiducials were placed successfully with only minor,self-limiting bleeding during puncture observed in 2 patients(6.9%).NACRT was subsequently administered to all patients and completed in 28/29(96.6%)cases,with one patient experiencing repeat cholangitis.Spontaneous migration of gold markers was observed in 1 patient.Twenty-four patients(82.8%)had surgery with 91.7%(22/24)R0 resection,and two patients experienced complete remission.No inflammatory changes around the marker were observed in the surgical specimen.The daily position of gold markers showed large positional changes,particularly in the superior-inferior direction.Moreover,tumor location was affected by food and fluid intake as well as bowel gas,which changes daily.CONCLUSION EUS fiducial marker placement following NACRT for RPC is feasible and safe.The RPC is mobile and is affected by not only aspiration,but also food and fluid intake and bowel condition.

超声内镜引导细针穿刺(EUS-FNA)诊断胰腺囊性疾病1例并文献复习

胰腺位于腹膜后,因此传统影像学方法诊断胰腺疾病,尤其是胰腺囊性疾病的准确度不高。超声内镜引导细针穿刺(EUS-FNA)做为一种全新的检查手段,具有创伤小、精准度高的优势,在胰腺囊性疾病的诊断和治疗中起着至关重要的作用。该文报道了我院1例87岁女性,经EUS-FNA获取病理后,确诊为胰腺囊肿并感染,为后续治疗提供有力证据。

Evaluation of clinical relevance of examining K-ras, p16 and p53 mutations along with allelic losses at 9p and 18q in EUS-guided fine needle aspiration samples of patients with chronic pancreatitis and pancreatic cancer

AIM： To establish an optimum combination of molecular markers resulting in best overall diagnostic sensitivity and specificity for evaluation of suspicious pancreatic mass. METHODS： Endoscopic ultrasound （EUS）-guided fine needle aspiration cytology （FNA） was performed on 101 consecutive patients （63 males, 38 females, 60 ± 12 years; 81 with subsequently diagnosed pancreatic cancer, 20 with chronic pancreatitis） with focal pancreatic mass. Samples were evaluated on-site by an experienced cytopathologist. DNA was extracted from Giemsa stained cells selected by laser microdissection and the presence of K-ras, p53 and p16 somatic mutations was tested by cycling-gradient capillary electrophoresis （CGCE） and single-strand conformation polymorphism （SSCP） techniques. In addition, allelic losses of tumor suppressor genes p16 （INK4, CDKN2A） and DPC4 （MADH4, SMAD4） were detected by monitoring the loss of heterozygosity （LOH） at 9p and 18q, respectively. RESULTS： Sensitivity and specificity of EUS-guided FNA were 75% and 85%, positive and negative predictive value reached 100%. The remaining 26% samples were assigned as inconclusive. Testing of molecular markers revealed sensitivity and specificity of 70% and 100% for K-ras mutations （P 〈 0.001）, 24% and 90% for p53 mutations （NS）, 13% and 100% for p16 mutations （NS）, 85% and 64% for aUelic losses at 9p （P 〈 0.001） and 78% and 57% for allelic losses at 18q （P 〈 0.05）. When tests for different molecular markers were combined, the best results were obtained with K-ras ＋ LOH at 9p （92% and 64%, P 〈 0.001）, K-ras ＋ LOH at 18q （92% and 57%, P 〈 0.001）, and K-ras ＋ LOH 9q ＋ LOH 18q （96% and 43%, P 〈 0.001）. When the molecular markers were used as complements to FNA cytology to evaluate inconclusive samples only, the overall sensitivity of cancer detection was 100% in all patients enrolled in the study. CONCLUSION： EUS-guided FNA cytology combined with screening of K-ras mutations and allelic losses of tumor suppressors p16 and DPC4 represents a very sensitive approach in screening for pancreatic malignancy. Molecular markers may find its use particularly in cases where FNA cytology has been inconclusive.

Applications of endoscopic ultrasound in pancreatic cancer

Since the introduction of endoscopic ultrasound guided fine-needle aspiration(EUS-FNA),EUS has assumed a growing role in the diagnosis and management of pancreatic ductal adenocarcinoma(PDAC).The objective of this review is to discuss the various applications of EUS and EUS-FNA in PDAC.Initially,its use for detection,diagnosis and staging will be described.EUS and EUS-FNA are highly accurate modalities for detection and diagnosis of PDAC,this high accuracy,however,is decreased in specific situations particularly in the presence of chronic pancreatitis.Novel techniques such as contrast-enhanced EUS,elastography and analysis of DNA markers such as k-ras mutation analysis in FNA samples are in progress and might improve the accuracy of EUS in the detection of PDAC in this setting and will be addressed.EUS and EUS-FNA have recently evolved from a diagnostic to a therapeutic technique in the management of PDAC.Significant developments in therapeutic EUS have occurred including advances in celiac plexus interventions with direct injection of ganglia and improved pain control,EUS-guided fiducial and brachytherapy seed placement,fine-needle injection of intra-tumoral agents and advances in EUS-guided biliary drainage.The future role of EUS and EUS in management of PDAC is still emerging.

Role of endoscopic ultrasound in the molecular diagnosis of pancreatic cancer

Pancreatic ductal adenocarcinoma remains one of the most deadly types of tumor. Endoscopic ultrasoundguided fine-needle aspiration(EUS-FNA) is a safe, cost-effective, and accurate technique for evaluating and staging pancreatic tumors. However, EUS-FNA may be inconclusive or doubtful in up to 20% of cases. This review underlines the clinical interest of the molecular analysis of samples obtained by EUS-FNA in assessing diagnosis or prognosis of pancreatic cancer, especially in locally advanced tumors. On EUS-FNA materials DNA, mRNA and miRNA can be extracted, amplified, quantified and subjected to methylation assay. Kras mutation assay, improves diagnosis of pancreatic cancer. When facing to clinical and radiological presentations of pseudo-tumorous chronic pancreatitis, wildtype Kras is evocative of benignity. Conversely, in front of a pancreatic mass suspected of malignancy, a mutated Kras is highly evocative of pancreatic adenocarci-noma. This strategy can reduce false-negative diagnoses, avoids the delay of making decisions and reduces loss of surgical resectability. Similar approaches are conducted using analysis of miRNA expression as well as Mucin or markers of invasion(S100P, S100A6, PLAT or PLAU). Beyond the diagnosis approach, the prediction of response to treatment can be also investigated form biomarkers expression within EUS-FNA materials.

It is necessary to exam bottom and top slide smears of EUS-FNA for pancreatic cancer

Background: Despite many reports on the diagnostic yield of cytology from endoscopic ultrasound-guided fine-needle aspiration(EUS-FNA), inter-slide differences are unknown. This prospective study aimed to compare diagnostic yield and cellular characteristics of bottom slides(BS) and top slides(TS) from EUSFNA cytology performed without an on-site cytopathologist. Methods: In patients with suspected pancreatic cancer on previous imaging explorations, a single endoscopist performed EUS-FNA and obtained 2 sets of cytology slide(8 BS and 8 TS), 1 cellblock slide, and 1 biopsy slide. Both slide sets were randomly assigned. A cytopathologist with more than 10 years of expertise in pancreatic cytopathology blindly inspected and compared two slide sets. Results: In total, 73 specimens [42 head(57.5%), 16 body(21.9%), and 15 tail(20.5%)] were acquired for final analysis. Seventy-one cases were finally diagnosed with pancreatic cancer. The sensitivity and specificity of BS were 80.3% and 100.0%; and of TS 78.9% and 100.0%, respectively. In analyzing inter-slide difference, 66 cases(90.4%) showed consistent results between BS and TS. However, seven(9.6%) were positive only in one slide sets(4 BS and 3 TS). The proportions of specimens more than moderate and high cellularity were 75.3% and 60.3% in both slide sets( P > 0.99), and the proportion of artifact-free sets were 50.7%, and 52.1% for the BS and TS, respectively( P = 0.869). Conclusions: Although BS and TS exhibited highly consistent diagnostic yields in cytologic smears from EUS-FNA, the proportion of inter-slide discordance is clinically considerable. Both slide sets need to be examined if there is no on-site cytopathologist.

Bilateral thigh pyomyositis in an otherwise healthy middle-aged woman:A case report

BACKGROUND Pyomyositis generally occurs in otherwise healthy young men.Because this condition is unusual among otherwise healthy women in temperate climates,we present the following case.CASE SUMMARY An otherwise healthy 43-year-old woman presented with bilateral pain in her lower extremities and fever.Magnetic resonance imaging(MRI)findings were indicative of myositis with a possible abscess.We initiated empirical antibiotic therapy with ceftriaxone.However,the swelling and pain in her legs persisted even after 7 d of treatment.Contrast MRI revealed multiple pockets of pus in the vastus lateralis and gluteal muscles.We performed needle aspiration of these abscesses with ultrasound guidance and local anesthesia.Upon culturing,the purulent material was positive for Staphylococcus aureus.We diagnosed her with S.aureus-induced pyomyositis of the vastus lateralis muscle and gluteus region.Based on the antibiotic sensitivity report,ceftriaxone was administered for an additional 7 d.By day 15 post-drainage,the patient was able to start walking.Oral antibiotic therapy was continued for 1 wk following her discharge from hospital,after which her symptoms resolved completely.CONCLUSION Pyomyositis may present with muscle pain,swelling,and fever.Ultrasoundguided percutaneous puncture and drainage may enable timely diagnosis and treatment.

Clinical course of suspected small gastrointestinal stromal tumors in the stomach

BACKGROUND Gastric subepithelial lesions are frequently encountered during endoscopic examinations,and the majority of them are small and asymptomatic.Among these lesions,gastrointestinal stromal tumors(GISTs)are the major concern for patients and clinicians owing to their malignant potentials.Although previous guidelines suggested periodic surveillance for such small(≤20 mm)lesions,several patients and clinicians have still requested or prescribed repeated examinations or radical resection,posing extra medical burdens and risks.AIM To describe the clinical course of suspected small gastric GISTs and provide further evidence for surveillance strategy for tumor therapy.METHODS This single-center,retrospective study was conducted at West China Hospital,Sichuan University.Consecutive patients with suspected small gastric GISTs were reviewed from November 2004 to November 2018.GIST was suspected according to endoscopic ultrasonography features:hypoechoic lesions from muscularis propria or muscularis mucosa.Eligible patients with suspected small(≤20 mm)GISTs were included for analysis.Patients’demographic data,lesions’characteristics,and follow-up medical records were collected.RESULTS A total of 383 patients(male/female,121/262;mean age,54 years)with 410 suspected small gastric GISTs(1 lesion in 362 patients,2 lesions in 16,3 lesions in4,and 4 lesions in 1)were included for analysis.The most common location was gastric fundus(56.6%),followed by body(29.0%),cardia(12.2%),and antrum(2.2%).After a median follow-up of 28 mo(interquartile range,16-48;range,3-156),402 lesions(98.0%)showed no changes in size,and size of 8 lesions(2.0%)was increased(mean increment,10 mm).Of the 8 lesions with size increment,endoscopic or surgical resection was performed in 6 patients(5 GISTs and 1 leiomyoma).For other 2 remaining patients,unroofing biopsy or endoscopic ultrasound-guided fine-needle aspiration was carried out(2 GISTs),while no further change in size was noted over a period of 62-64 mo.CONCLUSION The majority of suspected small(≤20 mm)gastric GISTs had no size increment during follow-up.Regular endoscopic follow-up without pathological diagnosis may be highly helpful for such small gastric subepithelial lesions.

Mucosal-incision assisted biopsy for suspected gastric gastrointestinal stromal tumors

To evaluate the diagnostic yield of the procedure, mucosal-incision assisted biopsy (MIAB), for the histological diagnosis of gastric gastrointestinal stromal tumor (GIST), we performed a retrospective review of the 27 patients with suspected gastric GIST who underwent MIAB in our hospitals. Tissue samples obtained by MIAB were sufficient to make a histological diagnosis (diagnostic MIAB) in 23 out of the 27 patients, where the lesions had intraluminal growth patterns. Alternatively, the samples were insufficient (non-diagnosticMIAB) in remaining 4 patients, three of whom had gastric submucosal tumor with extraluminal growth patterns. Although endoscopic ultrasound and fine needle aspiration is the gold standard for obtaining tissue specimens for histological and cytological analysis of suspected gastric GISTs, MIAB can be used as an alternative method for obtaining biopsy specimens of lesions with an intraluminal growth pattern.

Role of the preoperative usefulness of the pathological diagnosis of pancreatic diseases

Pancreatic cancer is the fifth leading cause of cancer death and has the lowest survival rate of any solid cancer.Endoscopic ultrasound-guided fine-needle aspiration biopsy(EUS-FNA) is currently capable of providing a cytopathological diagnosis of pancreatic malignancies with a higher diagnostic power,with a sensitivity and specificity of 85%-89% and 98%-99%,compared to pancreatic juice cytology(PJC),whose sensitivity and specificity are only 33.3%-93% and 83.3%-100%.However,EUS-FNA is not effective in the cases of carcinoma in situ and minimally invasive carcinoma because both are undetectable by endoscopic ultrasonography,although PJC is able to detect them.As for the frequency of complications such as post endoscopic retrograde cholangiopancreatography pancreatitis,EUS-FNA is safer than PJC.To diagnose pancreatic cancer appropriately,it is necessary for us to master both procedures so that we can select the best methods of sampling tissues while considering the patient's safety and condition.