Kerosene condenses in the trachea following inhalation.

PURPOSE: We have investigated the absorption dynamics of petroleum fuel components from the analytical results of autopsy samples. METHODS: Post-mortem samples of the severely burned case, including femoral blood, intratracheal contents (mucus) and intratracheal gas-phase samples were collected, and analysed by gas chromatography-mass spectrometer with head-space solid-phase microextraction. RESULTS: The composition of flammable substances in the tracheal gas phase differed slightly from that in mucus. CONCLUSION: High-boiling point components are retained in the trachea, whereas relatively lower-boiling point components are detected predominantly in the tracheal gas phase and blood.

Case report: Fatal poisoning caused by additive effects of two barbiturates.

A case of fatal poisoning involving multiple psychotropic drugs is presented. Quantitative toxicological analysis showed femoral blood concentrations of pentobarbital, phenobarbital, duloxetine, acetaminophen and tramadol were 10.39, 22.57, 0.22, 0.61 and 0.22 µg/ml, respectively. We concluded that the death was due to the additive effects of two barbiturates. As both pentobarbital and phenobarbital act on gamma-aminobutyric acid (GABA) receptors, central nervous system activity was suppressed, causing respiratory depression. Additive pharmacological effects should be considered in cases of massive ingestion of multiple drugs.

Telomerase Reverse Transcriptase Promoter Mutations in Human Hepatobiliary, Pancreatic and Gastrointestinal Cancer Cell Lines.

BACKGROUND/AIM: The promoter region of the telomerase reverse transcriptase (TERT) gene is a regulatory element capable of affecting TERT expression, telomerase activity, and telomerase length. Mutations within the TERT promoter region are the most common mutations in many cancers. In this study, we characterized the TERT promoter mutation status in hepatobiliary, pancreatic, and gastrointestinal cancer cell lines. MATERIALS AND METHODS: TERT promoter mutation status was assessed by digital PCR in 12 liver cancer, 5 cholangiocarcinoma (CCA), 12 pancreatic cancer, 17 gastrointestinal cancer, and 3 healthy control cell lines. RESULTS: The C228T promoter mutation was detected in 9 liver cancer lines, and the C250T TERT mutation was detected in 1 oesophageal squamous cell carcinoma line. CONCLUSION: The C228T promoter mutation is specific to liver cancer cell lines among various gastrointestinal cancer cell lines. These data will contribute to future research on the tumorigenic mechanisms and clinical use of digital PCR to detect mutations.

Prognosis of probable autoimmune hepatitis patients: a single-center study in Japan.

Autoimmune hepatitis (AIH) is an idiopathic inflammatory liver disease with genetic susceptibility and unknown environmental triggers. The gold standard for diagnosis, International Autoimmune Hepatitis Group (IAIHG) scoring system, classifies AIH as definite or probable. Conventional research on probable AIH has focused on the Caucasian population and there is little data pertaining to the Asian population. This study aimed to assess and compare the prognosis of Japanese patients with probable and definite AIH. In the current study, patients with probable and definite AIH diagnosed based on IAIHG scores between 1987 and 2018 were enrolled. As a result, 72 patients with definite AIH and 49 patients with probable AIH were evaluated. Univariate analysis revealed age, fibrosis stage 4, and the fibrosis-4 index were prognostic factors for overall survival. Multivariate analysis indicated that age and liver cirrhosis significantly affected the overall survival. When the cut off albumin-bilirubin score was set appropriately, cirrhosis was differentially diagnosed using albumin-bilirubin score with 100% sensitivity and 70.5% specificity. Classification of probable or definite disease did not alter overall survival with statistical significance. In conclusion, our findings suggest that probable AIH should be managed as definite AIH is managed in Japanese population. The albumin-bilirubin score helps identify liver cirrhosis and is a prognostic biomarker for overall survival.

Efficacy of crystal violet for identifying the distal end in esophageal submucosal tunnel resection.

BACKGROUND: Endoscopic submucosal tunnel dissection (ESTD) has recently been an effective procedure for resecting large early esophageal neoplasm. However, excessive dissection beyond the distal limit may occur because the prepared distal end often cannot be distinguished through the tunnel. This study aimed to assess the efficacy and safety of a novel crystal violet navigation (CVN) for identifying the distal end. MATERIAL AND METHODS: In the observational case series study, all 22 patients who underwent esophageal ESTD using the CVN were included. When setting the distal end, the distal incision line was dyed purple using a crystal violet solution. The rates of purple color identified via the tunnel, successful tunnel penetration without extra dissection, en bloc and curative resection, procedure time for ESTD and CVN, and procedure-associated complications were evaluated. RESULTS: The rates of purple color and successful tunnel penetration were both 100%. En bloc and curative resection were 100%, and 86%, respectively. The mean total procedure time was 103.9 ± 46.2 (mean ± SD) minutes, while the mean time for the CVN was 14.1 ± 3.44 s. No complications were observed. CONCLUSIONS: The simple CVN method can be a navigation tool for identifying the distal end during the ESTD procedure.

Identification of microRNA associated with the elimination of hepatitis C virus genotype 1b by direct-acting antiviral therapies.

BACKGROUND AND AIM: Direct-acting antiviral (DAA) therapies have been proven to be highly effective for the eradication of hepatitis C virus (HCV) without resistance-associated substitutions (RASs). However, even in cases with no detected RASs, treatment sometimes fails, suggestive of the existence of some host-related factors involved in HCV eradication by DAAs. To explore such factors, we analyzed the serum microRNAs (miRNAs) of patients who received DAA treatment. METHODS: The serum miRNA expression levels of 39 patients with chronic HCV infection without any detectable RASs, who achieved sustained virological response with asunaprevir/daclatasvir or grazoprevir/elbasvir therapy, were investigated cyclopedically, using oligonucleotide microarrays. The effects of specific miRNAs on the replication of HCV were measured in the HCV genomic replicon containing Huh-7 hepatoma cells. RESULTS: Along with the disappearance of HCV, the expression quantiles of 16 miRNAs in the asunaprevir/daclatasvir group and 18 miRNAs in the grazoprevir/elbasvir group showed a tendency to increase or decrease. Among these molecules, adjustments for multiple testing yielded a significant differential expression at a false discovery rate of less than 5% for only one molecule, hsa-miR-762. Its expression quantile increased after HCV exclusion in all patients who had achieved sustained virological response. Quantitative polymerase chain reaction analysis validated a significant increase in the serum hsa-miR-762 after disappearance of HCV. On the contrary, hsa-miR-762 was decreased in the relapse and breakthrough of HCV in DAA failures. Transfection of hsa-miR-762 into cultured HCV-infected hepatocytes significantly decreased HCV-RNA replication. CONCLUSION: These data suggest that hsa-miR-762 is one of the host factors participating in HCV exclusion by DAA therapy.

A case report of granulocyte colony-stimulating factor-producing hepatocellular carcinoma that recurred after long-term complete response.

The granulocyte colony-stimulating factor (G-CSF) is a glycoprotein that stimulates cell proliferation and differentiation of precursor cells in the bone marrow. Several cases of G-CSF-producing malignant tumors in various organs have been reported, but there are only nine cases of G-CSF-producing hepatocellular carcinoma (HCC) reported in the English literature. G-CSF-producing tumors grow rapidly and have a high probability of distant metastases; thus, they generally have a poor prognosis. Given that the mechanism of the carcinogenesis of G-CSF-producing HCC remains unclear, an efficient treatment strategy also remains to be elucidated. We report herein a case of G-CSF-producing HCC accompanied by leukocytosis and high serum G-CSF concentrations in the disease progression stage after long-term complete response. We also reviewed previous reports to investigate the clinical behaviors of G-CSF-producing HCC, including our case. Clinicians should consider G-CSF-producing HCC in patients with a hepatic mass and drastic leukocytosis, without any evidence of infection and blood disorders. Early diagnosis and prompt therapy, including radical resection, may provide a more favorable prognosis.

The Effect of Gemcitabine on Cell Cycle Arrest and microRNA Signatures in Pancreatic Cancer Cells.

BACKGROUND/AIM: Gemcitabine, an inhibitor of DNA synthesis, is the gold standard chemotherapeutic agent for pancreatic ductal adenocarcinoma (PDAC). MicroRNAs (miRNAs) play critical roles in cancers, including PDAC. However, less is known about the effect of gemcitabine on PDAC cells and miRNA expression in PDAC. We evaluated the effect of gemcitabine on the cell cycle of PDAC cells in vitro and in vivo and on the miRNA expression profile. MATERIALS AND METHODS: Effects of gemcitabine on PK-1 and PK-9 cell growth were evaluated using a cell counting kit-8 assay. Xenografted mouse models were used to assess gemcitabine effects in vivo. RESULTS: Gemcitabine inhibited the proliferation and tumour growth of PK-1 cells, and induced S phase cell cycle arrest. Numerous miRNAs were altered upon gemcitabine treatment of PK-1 cells and xenograft models. CONCLUSION: Altered miRNAs may serve as potential therapeutic targets for improving the efficacy of gemcitabine in PDAC.

Aspirin inhibits hepatocellular carcinoma cell proliferation in vitro and in vivo via inducing cell cycle arrest and apoptosis.

Aspirin, a nonsteroidal anti­inflammatory drug (NSAID), is known to inhibit cell proliferation in a variety of cancers. However, the underlying mechanism of this inhibition remains unknown. We investigated the effects of aspirin on hepatocellular carcinoma (HCC) cells using in vitro and in vivo models. Six HCC cell lines and a liver cancer cell line including Huh­7 were used in assays that evaluated cell proliferation, cell cycle, and apoptosis. Flow cytometry, enzyme­linked immunosorbent assay (ELISA), western blot analysis, and phosphorylated receptor tyrosine kinase array were used to evaluate the effects of aspirin on the cells, and microRNAs (miRNAs) were analyzed by a miRNA array chip. The results were validated in vivo using a nude mouse model of Huh­7­xenografted tumors. Our results showed that aspirin exhibited an antiproliferative effect on all cell lines. Moreover, aspirin induced G0/G1 cell cycle arrest and modulated the levels of cell cycle­related molecules such as cyclin E, cyclin D1, and cyclin­dependent kinase 2 (Cdk2). In addition, aspirin upregulated the levels of caspase­cleaved cytokeratin 18, increased the proportion of early apoptotic cells, decreased the levels of clusterin and heat shock protein 70 (HSP 70), upregulated the levels of miRNA­137 and inhibited epidermal growth factor receptor (EGFR) activation. In addition, we observed that aspirin suppressed cell proliferation partially through the miRNA­137/EGFR pathway. Our in vivo results showed that aspirin reduced the growth of xenograft tumors in nude mice. In conclusion, aspirin was able to inhibit the growth of HCC cells by cell cycle arrest, apoptosis, and alteration of miRNA levels in in vitro and in vivo models.

Antihypertensive drug telmisartan suppresses the proliferation of gastric cancer cells in vitro and in vivo.

Gastric cancer is one of the most common malignancies diagnosed worldwide. Telmisartan, an angiotensin receptor blocker (ARB), suppresses the proliferation of cancer cells and the growth of tumors through an unknown mechanism. To identify the mechanism, the present study was designed to evaluate the effects of telmisartan on gastric cancer cell lines and tumors in vitro and in vivo and the associated signaling molecules were identified. It was shown here that telmisartan suppressed the proliferation of the cultured human gastric cancer cell lines MKN74, MKN1 and MKN45 as detected in the CCK­8 assay. In a mouse xenograft model of gastric cancer, telmisartan suppressed tumor growth by arresting the cell cycle at the G0/G1 phase through inhibition of the expression of cyclin D1, the catalytic subunit of cyclin dependent kinase 4 (CDK4), as well as the phosphorylation of the tumor suppressor retinoblastoma (pRb) protein as detected by western blotting. Notably, telmisartan did not induce apoptosis, as indicated by consistent levels of caspase­cleaved keratin 18 in MKN74 cells. Furthermore, telmisartan inhibited the phosphorylation of epidermal growth factor receptor (EGFR) and increased the levels of the angiogenesis­related protein tissue inhibitor of metalloproteinase­1 (TIMP­1). Analyses of microarrays revealed that telmisartan altered the expression of miRNAs in MKN74 cells. In conclusion, telmisartan suppressed the proliferation of human gastric cancer cells by inducing cell cycle arrest.

Metformin Inhibits Proliferation and Tumor Growth of QGP-1 Pancreatic Neuroendocrine Tumor Cells by Inducing Cell Cycle Arrest and Apoptosis.

BACKGROUND/AIM: Pancreatic neuroendocrine tumors (pNETs) are rare pancreatic neoplasms, and therapeutic options for pNETs are limited. Metformin is an anti-hypoglycemic drug that appears to have anticancer effects. However, little is known about the effect of metformin on pNETs. In this study, we investigated the anti-proliferative effect of metformin on a human pNET cell line. MATERIALS AND METHODS: The anti-proliferative properties of metformin were evaluated in QGP-1 and NCI-H727 cells using a cell counting kit-8 assay. Xenograft mouse models were used to assess the tumor effect in vivo. RESULTS: Metformin inhibited the proliferation and anti-tumor growth of QGP-1 cells, accompanied by their arrest during the cell cycle at the G0/G1 phase. Immunohistochemical analysis of tumor tissues revealed down-regulation of cyclin D1 and proliferating cell nuclear antigen in the metformin-treated group. Additionally, metformin induced apoptosis, and the expression of survivin and claspin were decreased in metformin-treated QGP-1 cells according to the apoptosis array. Furthermore, the angiogenic related protein TIMP-1 was down-regulated, and its miRNA expression was altered by metformin in QGP-1 cells. CONCLUSION: Taken together, our study demonstrated the therapeutic potential of metformin and provides molecular mechanistic insights into its anti-tumoral effect on pNETs. This study is the first one describing anti-tumoral effects in pNETs.

Anti-diabetic drug metformin inhibits cell proliferation and tumor growth in gallbladder cancer via G0/G1 cell cycle arrest.

Gallbladder cancer is the most common biliary tract cancer with poor prognosis and wide variation in incidence rates worldwide, being very high in some countries in Latin America and Asia. Treatment of type 2 diabetes with metformin causes a reduction in the incidence of cancer. Till date, there are no reports on the anti-tumor effects of metformin in gall bladder cancer. Therefore, this study evaluated the effects of metformin on the proliferation of human gallbladder adenocarcinoma cells in vitro and in vivo, as well as explored the microRNAs associated with the anti-tumor effects of metformin. Metformin inhibited the proliferation in gallbladder adenocarcinoma cell lines NOZ, TGBC14TKB, and TGBC24TKB, and blocked the G0 to G1 transition in the cell cycle. This was accompanied by strong reduction in the expression of G1 cyclins, especially cyclin D1 and its catalytic subunits including cyclin-dependent kinase 4, and in retinoblastoma protein phosphorylation. In addition, metformin reduced the phosphorylation of receptor tyrosine kinases, especially Tie-2, ALK, PYK, EphA4, and EphA10, as well as angiogenesis-related proteins, including RANTES, TGF-ß, and TIMP-1. Moreover, metformin also markedly altered microRNA expression profile leading to an anti-tumor effect. Treatment of athymic nude mice bearing xenograft tumors with metformin inhibited tumor growth. These results suggest that metformin may be used clinically for the treatment of gallbladder adenocarcinoma.

Efficacy of combined modality therapy with sorafenib following hepatic arterial injection chemotherapy and three-dimensional conformal radiotherapy for advanced hepatocellular carcinoma with major vascular invasion.

The prognosis of hepatocellular carcinoma (HCC) patients exhibiting macroscopic vascular invasion (MVI) is poor, and the most appropriate treatment approach remains unclear. The current study aimed to investigate the efficacy and safety of sorafenib treatment following chemoradiotherapy for advanced HCC exhibiting MVI. A newly reported regimen, including 5-fluorouracil and cisplatin therapy (NewFP), plus three-dimensional conformal radiotherapy (3D-CRT) for MVI was used as the initial treatment. Additionally, sorafenib, as a secondary treatment, was administered after NewFP plus 3D-CRT for MVI. The present retrospective study enrolled patients with unresectable advanced HCC that was treated with NewFP plus 3D-CRT for MVI between January 2009 and December 2017. In total, 32 HCC patients with MVI were registered. Of these 32 patients, 18 were treated with NewFP plus 3D-CRT for MVI (NewFP + 3D-CRT group) and 14 were treated with sorafenib following NewFP plus 3D-CRT for MVI (sorafenib after NewFP + 3D-CRT group). The study endpoints were overall survival, overall response rate and disease control rate. Clinical factors influencing overall survival were identified using univariate and multivariate analyses. The median survival time in the NewFP + 3D-CRT group and sorafenib following NewFP + 3D-CRT group was 6.7 and 49.2 months, respectively (P=0.0003). For patients with advanced HCC exhibiting MVI, the initial treatment with NewFP plus 3D-CRT for MVI was well tolerated. The administration of sorafenib as the secondary treatment following NewFP plus 3D-CRT for MVI was associated with a significantly higher overall response rate, disease control rate and increased overall survival as compared with the NewFP plus 3D-CRT treatment.

Prediction of Transplant-Free Survival through Albumin-Bilirubin Score in Primary Biliary Cholangitis.

Albumin-bilirubin (ALBI) grade is defined using the ALBI score, which is calculated based on total serum bilirubin and albumin. This study aimed to evaluate the diagnostic ability of the ALBI score for determining hepatic fibrosis stage and transplant-free survival in primary biliary cholangitis (PBC) patients. A total of 181 Japanese patients with biopsy-proven or serologically diagnosed PBC were enrolled. The pathological stage was assessed using the Scheuer classification. The ALBI score differentiated fibrosis in stage 4 from that of 3 in the biopsy-proven cohort (p < 0.05). With an ALBI score cut-off value of -1.679, the sensitivity and specificity were 100% and 91.1%, respectively, with a likelihood ratio of 12.3 to differentiate stage 4 from stages 1-3. The ALBI score at the beginning of ursodeoxycholic acid (UDCA) prescription correlated with the two prognostic scores calculated after 1-year UDCA treatment. Kaplan-Meier analysis showed that the baseline ALBI score differentiated liver transplant-free survival (p < 0.05). The ALBI score presented a greater hazard ratio for transplant-free survival than aspartate aminotransferase-to-platelet ratio index (APRI) in Cox proportional hazard model. In conclusion, ALBI score indicates pathological stage in Japanese PBC patients and scores before UDCA prescription predict better liver transplant-free survival, which correlated well with the two major prognostic scores. The prognosis-predicting ability of the ALBI score might surpass that of APRI.

Albumin-Bilirubin Score Differentiates Liver Fibrosis Stage and Hepatocellular Carcinoma Incidence in Chronic Hepatitis B Virus Infection: A Retrospective Cohort Study.

The albumin-bilirubin (ALBI) score was originally established to stratify prognosis in patients with cirrhosis. The diagnostic accuracy of ALBI score in liver fibrosis staging in patients with chronic hepatitis B remains to be investigated. The present retrospective study, therefore, aimed to evaluate the ability of this score to stage liver fibrosis in these patients. Briefly, consecutive patients with hepatitis B virus (HBV) infection who underwent liver biopsy examinations in Kagawa University Hospital were enrolled. Liver fibrosis stage was assessed using a modified Meta-Analysis of Histological Data in Viral Hepatitis score. Albumin-bilirubin scores were calculated according to the following equation: (log10 total bilirubin [T-Bil] × 0.66) + (albumin [Alb] × -0.085). A total of 91 patients were enrolled in this study. Albumin-bilirubin score was able to differentiate stage 4 from stage 3 fibrosis (P < 0.05). When an ALBI score of -2.190 was adopted as the cutoff value for differentiating stage 4 from stages 1-3, the sensitivity, specificity, and positive likelihood ratio were 85.7%, 74.0%, and 3.300, respectively. Kaplan-Meier analysis showed that baseline ALBI scores < -2.190 correlated with better hepatocellular carcinoma (HCC)-free survival (P < 0.05). In conclusion, ALBI score can be used for liver fibrosis staging in Japanese chronic hepatitis B patients and can help distinguish cirrhotic from non-cirrhotic status. Furthermore, ALBI score was useful as a prognosis biomarker in our patients, with smaller ALBI scores predicting better HCC-free survival. Because calculating ALBI score is easy using serum T-Bil and Alb alone, ALBI score will help clinicians with decision-making in management of HBV-infected patients.

Albumin-bilirubin score indicates liver fibrosis staging and prognosis in patients with chronic hepatitis C.

AIM: Albumin-bilirubin (ALBI) grade was investigated to predict prognosis of patients with cirrhosis. It was defined using the ALBI score calculated based on serum total bilirubin and albumin, which represent liver function. The diagnostic accuracy for liver fibrosis staging in patients with chronic hepatitis using the ALBI score has not been investigated well. This study aimed to evaluate the diagnostic abilities of the ALBI score for liver fibrosis staging in chronic hepatitis and cirrhosis in Japanese patients with hepatitis C virus (HCV) infection. METHODS: Japanese patients with HCV infection who underwent liver biopsy examinations were enrolled in a retrospective study. Fibrosis staging and activity grading were assessed using the modified METAVIR score. The ALBI score was calculated according to the following equation: Log10 total bilirubin (µmol/L) × 0.66 + albumin (g/L) × (-0.085). RESULTS: A total of 382 patients were enrolled in this study. The ALBI score differentiated fibrosis stage 4 from 3 and stage 3 from 2 (P < 0.05). When an ALBI score of -2.125 was adopted as a cut-off value, the sensitivity and specificity were 73.2% and 87.1%, respectively, with a positive likelihood ratio of 5.67 to differentiate stage 4 from stages 1-3. Kaplan-Meier analysis showed that smaller ALBI scores at baseline correlated with better hepatocellular carcinoma (HCC)-free and overall survival (P < 0.05). CONCLUSIONS: The ALBI score indicates liver fibrosis staging in Japanese patients with HCV infection. Furthermore, smaller ALBI scores predict better HCC-free survival and overall survival. The ALBI score has the potential to expand its application from cirrhosis to chronic hepatitis.

Long-Term Management of Recurrent Cholecystitis after Initial Conservative Treatment: Endoscopic Transpapillary Gallbladder Stenting.

Background: Endoscopic transpapillary gallbladder stenting (ETGBS) is an effective procedure for treating high-risk patients with acute cholecystitis and severe comorbidities. However, the efficacy of ETGBS for recurrent cholecystitis (RC) remains unclear. This study aimed to explore its efficacy in patients with RC for whom cholecystectomy is contraindicated because of its high surgical risk. Methods: Data on 19 high-risk patients who had undergone ETGBS for RC after initial conservative therapy in our institution between June 2006 and May 2012 were retrospectively examined. The primary outcome was the clinical success rate, which was defined as no recurrences of acute cholecystitis after ETGBS until death or the end of the follow-up period. Secondary outcomes were technical success rate and adverse events (AEs). Results: The clinical success rate of ETGBS was 100%, the technical success rate 94.7%, and AE rate 5%: one patient developed procedure-related mild acute pancreatitis. The clinical courses of all patients were as follows: four died of nonbiliary disease, and the remaining 15 were subsequently treated conservatively. The median duration of follow-up was 14.95 months (range 3-42 months). Conclusions: ETGBS is an effective alternative for managing RC in high-risk patients with severe comorbidities.

Comparison of histological findings and the results of energy-dispersive X-ray spectrometry analysis in experimental electrical injury.

The findings of histological examination and the results of energy-dispersive X-ray spectrometry (EDX) analysis were compared to identify skin metallization in experimental electrical injury. Rats were divided into three experimental groups (n = 5, each group): control, current exposure for five seconds, and current exposure for ten seconds. A relatively high peak of copper, which was used as an electrical conductor, was detected in formalin-fixed skin samples of the two current exposure groups by EDX. There was a significant increase of the specific X-ray intensity in the two current exposure groups compared to the control group. On histological examination, epidermal nuclear elongation was observed in all samples of the two current exposure groups. However, deposition of metal was observed in two samples of each current exposure group. Metallization is an important finding for the diagnosis of electrocution. The present results suggest that EDX analysis is useful for the proof of metallization in electrocution, even where it is not identified on morphological examination.

An autopsy case of death by combined use of benzodiazepines and diphenidine.

We present an autopsy case involving benzodiazepines and diphenidine. Quantitative toxicological analysis showed concentrations of 7-aminoflunitrazepam (a flunitrazepam metabolite), 7-aminonimetazepam (a nimetazepam metabolite), chlorpheniramine and diphenidine in femoral blood of 0.086 µg/ml, 0.027 µg/ml, 0.066 µg/ml, and 0.073 µg/ml, respectively. Death was attributed to combined toxicity due to the influence of multiple drug interactions.

Comparison of submucosal tunneling biopsy versus EUS-guided FNA for gastric subepithelial lesions: a prospective study with crossover design.

BACKGROUND AND STUDY AIMS: Endoscopic ultrasound-guided fine needle aspiration (FNA) for gastrointestinal subepithelial lesions (SELs) has limited diagnostic accuracy due to technical problems and small lesion size. We previously reported a novel submucosal tunneling biopsy (STB) technique for sampling SELs. This study aimed to evaluate the diagnostic ability and safety of STB compared to that of FNA for SELs. PATIENTS AND METHODS: The study was a non-randomized, prospective comparative study with crossover design in patients with endoluminal gastric SELs. Forty-three patients, including 29 cases with lesions < 2 cm were enrolled. A crossover design with 2 intervention stages (Group A: FNA followed by STB for 23 SELs, Group B: STB followed by FNA for 20 SELs) was implemented. The primary outcome was the diagnostic yield (DY). Secondary outcomes were technical success rate, procedure time, complication rate, and sample quality. RESULTS: The DY of STB was significantly higher than that of FNA (100 % vs. 34.8 %; P  < 0.0001) in group A, including 100 % in overall STB. The technical success rate of STB was significantly higher than that of FNA (100 % vs. 56.5 %; P  = 0.0006), whereas the median procedure time of STB was significantly longer than that of FNA (37 minutes vs. 18 minutes; P  < 0.0001). The median specimen area of STB samples was markedly larger than that of FNA samples (5.54 mm 2 vs. 0.69 mm 2 ; P  < 0.001). No complications occurred in either method. CONCLUSIONS: STB had significantly superior diagnostic ability and a more adequate sample quality than FNA for endoluminal gastric SELs, indicating the suitability of STB for small SELs. CLINICAL TRIAL REGISTRATION: UMIN 000006754.