A rare incidence of a hepatic artery pseudoaneurysm following plastic biliary stent insertion.

Hepatic artery pseudoaneurysms have been reported to occur in approximately 1% of cases after metal stenting for malignant biliary obstruction. In contrast, only a few cases have been reported as complications after plastic stenting for benign biliary disease. We report a 61-year-old man with cholangitis who presented with a rare complication of hemobilia after implantation of 7 Fr double pigtail plastic biliary stents. No bleeding was observed approximately one month after biliary stent tube removal. Contrast-enhanced CT scan revealed a circularly enhanced lesion (5 mm in diameter) in the arterial phase at the tip of the previously inserted plastic bile duct stent. Color Doppler ultrasonography enhanced the lesion and detected arterial blood flow inside. He was diagnosed with a hepatic artery pseudoaneurysm. However, he had no risk factors such as prolonged catheterization, severe cholangitis, liver abscess, or long-term steroid use. Superselective transarterial embolization using two metal microcoils was successfully completed without damage to the surrounding liver parenchyma. If hemobilia is suspected after insertion of a plastic bile duct stent, immediate monitoring using contrast-enhanced computed tomography or Doppler ultrasonography is recommended.

Surgery for Hepatocellular Carcinoma With Macroscopic Vascular Invasion in the Era of Modern Molecular Therapy.

It has been reported that patients with macroscopic vascular invasion accompanying hepatocellular carcinoma have a poor prognosis. Modern molecular therapy with multitargeted tyrosine kinase inhibitors and immune checkpoint inhibitors has shown promising results in patients with metastatic hepatocellular carcinoma; however, molecular therapy is limited to patients with Child-Pugh class A disease. This review summarizes the present status of surgical therapies, including conversion hepatectomy, for patients with MVI in the developing era of novel molecular therapy. Phase III studies showed patients with macroscopic vascular invasion had significant survival benefits from sorafenib [hazard ratio (HR)=0.68] and regorafenib (HR=0.67) versus placebo, and nivolumab (HR=0.74) versus sorafenib. Lenvatinib and atezolizumab plus bevacizumab showed marginal effects. It is currently widely assumed that molecular therapy alone will not cure the disease but that additional conversion hepatectomy will be required. A response other than progressive disease is essential but a pathological complete response is not always required. A significant randomized controlled trial has already started in China to assess the necessity for conversion hepatectomy after effective atezolizumab plus bevacizumab treatment, and the results are still awaited. According to Japanese national data, upfront hepatectomy can be recommended for patients with initially resectable disease and macroscopic vascular invasion other than for those with tumors in the main portal vein and the inferior vena cava. In addition, adequate adjuvant therapies with hepatic arterial chemotherapy and transarterial chemoembolization may be beneficial but an effective adjuvant molecular therapy is currently unavailable. In conclusion, novel molecular therapies with higher response rates customized to the oncologic characteristics of each hepatocellular carcinoma with macroscopic vascular invasion are needed to increase the likelihood of conversion surgery and improve long-term outcomes.

Durable Stable Disease by Atezolizumab/Bevacizumab Can Provide Long-term Survival of Patients With Hepatocellular Carcinoma Lung Metastases.

BACKGROUND: Multiple bilateral lung metastases secondary to hepatocellular carcinoma (HCC) are mainly treated with molecular therapy. Atezolizumab plus bevacizumab can provide excellent long-term survival for patients with a good response. CASE REPORT: A 67-year-old woman underwent right hepatectomy for a primary solitary HCC, 11 cm in diameter, after portal embolization. After 2 years, she developed bilateral lung metastases with >100 nodules, <1 cm in size. She had no viral hepatitis or liver cirrhosis, and the Child-Pugh Grade was A (5 points). Lenvatinib (12 mg daily) was administered as a first-line treatment and continued for 18 months. The best response was stable disease (SD). Subsequently, intravenous atezolizumab (1,200 mg) plus bevacizumab (15 mg/kg) was administered once every three weeks. The best response was SD, which continued for 26 months. After that, cabozantinib treatment was initiated and discontinued after one cycle. Subsequently, dual immune checkpoint inhibitor treatment (durvalumab + tremelimumab) was administered. She has had multiple, but lung-only, metastases over four years. She has been well as an outpatient with the Child-Pugh Grade of A and a performance status of 0. CONCLUSION: Even if atezolizumab plus bevacizumab does not induce a good response, a durable SD could prolong survival in patients with metastatic HCC while maintaining liver function and a good quality-of-life.

A Laparoscopically Treated Case of Peritoneal Dissemination Mimicking Liver Metastases from Distal Cholangiocarcinoma Four Years After the Initial Pancreaticoduodenectomy.

BACKGROUND/AIM: Operable peritoneal dissemination from distal cholangiocarcinoma after pancreaticoduodenectomy is rare. Furthermore, peritoneal dissemination mimicking liver metastasis has scarcely been reported. CASE REPORT: An 81-year-old woman received pancreaticoduodenectomy for distal cholangiocarcinoma. She was diagnosed with stage IIA (T3a N0 M0) and received curative resection. She did not receive adjuvant chemotherapy. As a result of the examination in our department, she showed two tumors, 20 mm and 8 mm in segments 7/8 and 7, respectively, in the subphrenic liver surface four and half years after the initial pancreaticoduo-denectomy. The larger tumor was slow-growing, and cystic degeneration was inside. Plain computed tomography imaging revealed an isodense tumor with a marginal high ring and weak early enhancement, and prolonged peripheral enhancement was recognized at the marginal portion. Magnetic resonance imaging showed a heterogeneous mass with peripheral hypointensity ring that may be caused by fibrous tissue. Although the smaller tumor was diagnosed only after admission, it presented similar imaging findings to the larger tumor. The preoperative diagnosis was suspected to be liver metastases from DCC or inflammatory pseudotumor. Laparoscopic partial liver resection with diaphragm dissection was performed for both tumors. Pathologically, the tumors were diagnosed as peritoneal dissemination from distal cholangiocarcinoma. In the disseminated cancer cells, the expression of Ki67 was decreased, which was suspected to be one of the reasons for the long recurrence-free interval. The patient is doing well without any recurrence three months after the second operation. CONCLUSION: Laparoscopic surgery can provide excellent results for diagnosing and treating unknown subphrenic tumors.

Vater Papilla-preserving Strategy for Advanced Hepatocellular Carcinoma With Excessive Bile Duct Tumor Thrombus.

BACKGROUND/AIM: Hepatocellular carcinoma (HCC) with bile duct tumor thrombus (BDTT) is highly malignant; therefore, continual, multidisciplinary treatments are essential. CASE REPORT: In this study, two 78- and 81-year-old men were treated with the Vater papilla-preserving strategy. Case 1 had advanced HCC with BDTT expanding to the common bile duct (B4) and portal vein tumor thrombus (PVTT) of the umbilical portion. He showed triple-positive tumor markers. He underwent an extended left hepatectomy without bile duct resection following percutaneous transhepatic biliary drainage and transarterial chemoembolization (TACE). Later, TACE in combination with percutaneous microwave ablation was performed to treat four intrahepatic recurrent HCCs. Case 2 had diffuse-type HCCs accompanied by BDTT (B4) and PVTT to the right portal vein. He underwent liver partition associated with portal vein ligation for staged hepatectomy without bile duct resection. Six months later, he developed a solitary recurrent BDTT with obstructive jaundice. After percutaneous transhepatic biliary drainage, he was treated with two TACE from the various feeding arteries. Both patients achieved complete responses and are doing well without viable tumors approximately 2 years after the initial treatment. CONCLUSION: The Vater papilla-preserving strategy is essential for obtaining long-term survival and recurrent-free status for patients with HCC with highly extended BDTT.

Successful Treatment of Intrahepatic Cholangiocarcinoma With Liver/Lung Metastasis and Peritoneal Dissemination After Liver Resection.

BACKGROUND/AIM: Intrahepatic cholangiocarcinoma (ICC) is increasing in incidence and has a poor prognosis. CASE REPORT: A 79-year-old woman with two liver tumors was referred to our institution. The tumors demonstrated irregular margins and continuous peripheral enhancement. She had a good liver function and an elevated CA19-9 level. Extended left hepatectomy, and partial hepatectomy was performed. The patient was diagnosed with poorly differentiated ICC. Two lung metastases, one liver metastasis, and localized intraperitoneal dissemination occurred 19, 24, and 32 months after the initial hepatectomy. The lung metastases were treated with computed tomography-guided radiofrequency ablation approximately after one year of observation. The liver metastasis was resected immediately. The peritoneal dissemination was removed entirely after effective 3-month chemotherapy using gemcitabine and S-1. The patient is alive with no tumor 44 months after the first surgery. CONCLUSION: Multidisciplinary treatment considering a metastatic site and tumor malignancy might be effective for patients with ICC who have multiple recurrences.

Highly Advanced Colorectal Liver Metastases Successfully Treated With Fluorouracil Plus Leucovorin Monotherapy and Microwave Ablation.

BACKGROUND: Fluorouracil plus leucovorin (5-FU/LV) is a less toxic but mild chemotherapy. CASE REPORT: A 63-year-old male patient with rectal cancer and multiple colorectal liver metastases (CRLM, total volume of 1,826 ml) was hospitalized. He had several poor prognostic factors, including elevated levels of tumor markers, with carcinoembryonic antigen and carbohydrate antigen 19-9 levels of 17,119 ng/ml and 7,617 U/ml, respectively. Additionally, the patient had a low body mass index, poor performance status, and a history of apparent weight loss. After capecitabine and oxaliplatin for four cycles, 5-FU/LV has been lasting for nine months. Interestingly, tumor marker levels returned close to normal limits, and the total CRLM volume decreased to 154 ml without any enhancements. The patient's general condition clearly improved after a year of chemotherapy. CONCLUSION: Chemotherapy with 5-FU/LV and percutaneous microwave ablation is beneficial to achieve tumor control in patients with highly advanced liver-only CRLM and poor general condition.

Far-advanced Colorectal Liver Metastases Successfully Managed With Modified ALPPS and Radiofrequency Ablation in Combination With Chemotherapy.

BACKGROUND: Large numbers of synchronous colorectal liver metastases are associated with poor prognosis. CASE REPORT: A 47-year-old male patient with rectal cancer and unresectable colorectal liver metastases (over 15 cm in diameter and over 30 metastases) was treated with a multidisciplinary treatment including systemic chemotherapy with mFOLFOX6/panitumumab and surgical therapies (colostomy, modified associating liver partition and portal vein ligation for staged hepatectomy together with radiofrequency ablation). For solitary recurrent colorectal liver metastases, percutaneous radiofrequency ablation with chemoembolization and open radiofrequency ablation in combination with the same systemic chemotherapy was performed. Since the diagnosis 3 years ago, he has been leading a good quality of life, free of any tumor or treatment. CONCLUSION: For patients with far-advanced but liver-only colorectal liver metastases, surgical therapy, systemic chemotherapy, and interventional treatment can be important for achieving good prognosis.

A Case Report of Metachronous Multiple Adenosquamous Carcinoma of the Colon Over-expressing PD-L1 and a Literature Review.

BACKGROUND: Colorectal cancer is the third most commonly diagnosed cancer in both men and women, and one of the more widely recognized preventable cancers. Adenosquamous carcinoma (ASC) of the colon/rectum is an uncommon disease that consists of both glandular and squamous components, and the most common site of ACS is the right and transverse colon. CASE REPORT: Here, we present the case of a 78-year-old woman, who complained of abdominal pain. Colonoscopy revealed a circumscribed tumor in the ascending colon, and no specific lesion was detected in the other areas of the colon or rectum. ASC (pT3N0M0) was diagnosed from right hemicolectomy specimens. Three months after the first surgery, the serum levels of tumor markers had gradually increased, and a new tumor was subsequently detected in the sigmoid colon 2 months later. The sigmoid lesion was surgically resected and diagnosed as ASC (pT3N3M0). Strong PD-L1 expression was also found in the squamous component. CONCLUSION: To our knowledge, this is the first report of a recurrent sigmoid colon ASC that likely originated from the ascending colon, and PD-L1/PD-1 signaling was likely involved in the immune escape mechanism.

Intrahepatic Cholangiocarcinoma Coexisting With Multiple Bile Duct Adenoma Treated as Liver Metastasis from a Pancreatic Neuroendocrine Tumor.

BACKGROUND: Bile duct adenomas (BDA) may be precursor lesions of small duct-type, including mass-forming type intrahepatic cholangiocarcinoma (ICC). CASE REPORT: A 68-year-old woman was transferred to our facility for the treatment of a liver tumor, possibly metastasized from a pancreatic neuroendocrine tumor. Finally, two liver tumors were resected and histopathologically diagnosed as "BDA" and "ICC with a BDA-like component". In the BDA-like component, the MUC6 positive rate was notably lower and the Ki-67 positive rate was higher than the other BDAs and ICC component, respectively. The doubling time of the tumor volume in BDA was very long but was shortened (1,510 and 719 days). Distinct enlargement of the tumor and appearance of enhancement through diagnostic imaging was useful in diagnosing the transformation from a BDA to an ICC. CONCLUSION: An "adenoma-carcinoma sequence" may exist in the transformation process from a BDA to an ICC.

Laparoscopic Surgery for a Patient With Multiple Liver Metastases of Unknown Origin Concomitant With Gallbladder Tumor.

BACKGROUND: The liver is the digestive organ where metastatic adenocarcinoma of unknown primary site is most often observed. CASE REPORT: A 74-year-old man was diagnosed with a growing gallbladder tumor and multiple liver tumors limited to the left lateral sector. Liver tumors were suggested to be primary or secondary adenocarcinoma with no relation to the gallbladder tumor. Also for diagnostic purposes, laparoscopic full-thickness resection of the gallbladder, laparoscopic lateral sectionectomy and lymph node sampling were performed. The final histopathological diagnosis was hyperplastic polyp of the gallbladder and metastatic poorly differentiated adenocarcinoma of the liver. Liver tumors were suspected to originate from the stomach, duodenum, or small intestine; however, the primary sites could not be identified. The patient has been closely followed up without any chemotherapy 3 months after surgery. CONCLUSION: Laparoscopic surgery can be strongly recommended for patients with multiple liver tumors of unknown origin concomitant with a gallbladder tumor.

Hepatic Inflammatory Pseudotumor Mimicking Malignant Tumor With Rare Onset of Intra-abdominal Hemorrhage.

BACKGROUND: Hepatic inflammatory pseudotumor (HIPT) is an uncommon benign tumor-like mass that mimics malignant tumors. CASE REPORT: A 73-year-old man was admitted with severe epigastric pain and high fever. He had received choledocojejunostomy. Enhanced computed tomography showed a 76 mm, heterogeneous, gradual enhanced low-density mass in the caudate lobe and hyperdense fluid was detected around the mass. Based on the diagnosis of hemorrhage from a hypervascular malignant liver tumor, chemoembolization was conducted. Antibiotics (Meropenem) were administered for 2 weeks, and methylprednisolone (125 mg) was administered twice as a premedication for chemoembolization. After the 2nd chemoembolization, rapid tumor shrinkage was observed and the inflammatory changes gradually disappeared. The tumor was finally diagnosed as fibrohistiocytic type HIPT with an ultrasound-guided percutaneous tumor biopsy. The diameter of the liver tumor decreased to 15 mm and intra-abdominal hemorrhage disappeared in 3 months. CONCLUSION: Development of HIPT can be associated with intra-abdominal hemorrhage.

Huge hepatocellular carcinoma with extrahepatic collateral arteries successfully treated by multidisciplinary treatment including laparoscopic devascularization: a case report.

Multidisciplinary treatment is recommended for the management of patients with advanced hepatocellular carcinoma (HCC). Some operative decollateralization of extrahepatic feeding arteries with laparotomy have been introduced for HCC. We herein newly develop laparoscopic devascularization (LDEV) to continue transarterial chemoembolization (TACE) for HCC with extrahepatic collateral arteries. A 74-year-old man with multiple huge HCC (4 tumors, 18 cm in diameter) and poor liver function (non-alcoholic steatohepatitis, Child-Pugh score 7) was treated with 6 times of chemoembolization in combination with LDEV, 3 times of ablation therapies, and lenvatinib therapy. His tumor markers were triple positive (AFP, 12,906.5 ng/ml; PIVKA-II, 491,743 mAU/ml; AFP-L3, 91.8%) before treatments; however, they all returned to normal limits. Complete response was achieved according to the modified RECIST criteria. Unfortunately, he died 6 months after the final treatment with no recurrence of HCC due to the postoperative complication of primary lung cancer. LDEV is a useful tool to continue effective TACE, and multidisciplinary treatment including chemoembolization and LDEV can cure advanced HCC patients with extrahepatic collaterals and impaired liver function.

Cholangiolocarcinoma With Multiple Recurrences Successfully Treated With Repeated Liver Resection and Radiofrequency Ablation.

BACKGROUND/AIM: The prognosis of cholangiolocarcinoma, a rare malignant liver tumor derived from hepatic progenitor or stem cells, is considered relatively good; however, it frequently recurs. We herein present the diagnosis, histological findings, and treatment of cholangiolocarcinoma. CASE REPORT: A 65-year-old woman with a large liver tumor (70 mm in diameter) was referred. Hepatocellular carcinoma was suspected based on strong early enhancement and delayed washout by enhanced computed tomography. The patient underwent curative left tri-sectionectomy. Histologically, she was diagnosed with pure cholangiolocarcinoma in a slightly fibrous liver. Three metachronous recurrent lesions (all ≤10 mm in diameter) were found between fifteen and twenty months after the initial hepatectomy. One lesion and the remaining two lesions were treated with hepatectomy and radiofrequency ablation, respectively. Two years after the initial diagnosis, she was doing well without recurrence. CONCLUSION: Repeated hepatectomy and radiofrequency ablation might be useful for small intrahepatic recurrences of cholangiolocarcinoma.

Hepatocellular Carcinoma With Extensive Cancer-associated Thrombosis Successfully Treated With Liver Resection and Direct Oral Anticoagulant: A Case Report.

AIM: To assess the utility of the perioperative use of direct oral anticoagulants for patients with hepatocellular carcinoma (HCC) with cancer-associated thrombosis. CASE REPORT: An 83-year-old woman was admitted with a solitary HCC (10-cm diameter), as well as with multiple sites of venous thromboembolism and macroscopic portal vein tumor thrombosis. She had appropriate liver function without viral hepatitis, triple-positive tumor markers, and secondary polycythemia. Edoxaban at 30 mg was initiated 10 days before surgery to remove HCC. Complete remission of the pulmonary embolism and stability of the deep vein thrombosis and massive superior mesenteric vein thrombosis were recognized preoperatively. An extended left hepatectomy was successfully performed. To avoid hemorrhage complications, we used intravenous administration of nafamostat mesylate for 2 days, thereafter we restarted edoxaban. Superior mesenteric vein thrombosis resolved 5 months after surgery. CONCLUSION: Perioperative oral administration of edoxaban was useful in multidisciplinary treatment for a patient with advanced HCC with cancer-associated thrombosis.

Complete Removal of Adrenal Metastasis in Hepatocellular Carcinoma Using Indocyanine Green Fluorescent Imaging.

AIM: Our aim was to confirm the utility of Indocyanine green (ICG) fluorescence imaging for intraoperative detection of adrenal hepatocellular carcinoma (HCC) metastasis. CASE REPORT: An 83-year-old man with a right adrenal HCC metastasis was admitted after complete remission of primary HCC and a metachronous left adrenal metastasis. He was treated with ICG fluorescence-guided limited resection to preserve adrenal function. ICG was administered intravenously at a dose of 0.5 mg/kg, 6 days before the operation. After removal of the entire suspicious metastatic HCC, ICG fluorescence imaging clearly demonstrated two illuminated lesions. The lesions were separately resected using an energy device. Finally, there were no ICG fluorescent lesions which meant residual tumor. Histopathological examination confirmed adrenal metastasis of moderately differentiated HCC in the initial specimen and the additional resected specimens. Three months after the operation, adrenal function was well preserved without recurrence of HCC. CONCLUSION: ICG fluorescence imaging is essential for complete resection of adrenal HCC metastasis.

Hepatic Xanthogranuloma that Originated from a Liver Cyst and Mimicked a Malignant Tumor.

BACKGROUND/AIM: Hepatic xanthogranuloma is a very rale disease and formation process is unknown. CASE REPORT: A 69-year-old woman previously diagnosed as simple liver cyst. Two years before, a 36-mm liver cyst was found in segment 5, while one year later, the hemorrhagic cyst was 40 mm in diameter and a thin septum had formed. The most recent T1-weighted magnetic resonance imaging (MRI) showed a regular 21-mm hepatic mass with a hyperintense 11-mm center and a hypointense periphery. Peripheral enhancement was seen on gadolinium enhanced MRI. Hepatobiliary cystadenoma or cystadenocarcinoma was suspected because of wall thickness and slight enhancement. Microscopic examination following laparoscopic partial liver resection revealed fibroblasts, dense collagen fibers, and a double layer of hemosiderin-laden as well as foamy macrophages attached to the fibrous capsule. CONCLUSION: The patient was diagnosed with a hepatic xanthogranuloma that originated from a hemorrhagic liver cyst. Intracystic hemorrhage may be one of the reasons for hepatic xanthogranuloma formation.

A hepatic sclerosed hemangioma with drastic changes in contrast-enhanced ultrasonography.

Hepatic sclerosed hemangioma is a rare benign liver tumor that originated from hepatic cavernous hemangioma; however, the process of its formation has been unclear. We herein present the patient of a histologically proven hepatic sclerosed hemangioma that showed drastic changes in diagnostic images in a short period. A 56-year-old man was referred to our hospital for the treatment of suspicious hepatocellular carcinoma with hepatitis C, approximately 2 cm in diameter in liver segment 8. Initially, the tumor manifested as early entire enhancement with mildly delayed washout in contrast-enhanced ultrasonography; however, it manifested as continuous peripheral enhancement with the central non-enhanced area after 1 month in various diagnostic images. He completely quit drinking and smoking 1 month preoperatively. No special symptoms and signs were found to suggest tumor ischemia. Anatomical resection of segment 8 was completed. Histological examination confirmed the final diagnosis of common type hepatic sclerosed hemangioma, derived from atypically enhancing cavernous hemangioma. No signs of impaired blood flow were observed in both diagnostic images and histological examination. Sclerosing changes in hepatic cavernous hemangioma may be completed in a relatively short time with no apparent reason.

Risk factors for pulmonary morbidities after minimally invasive esophagectomy for esophageal cancer.

BACKGROUND: Pulmonary morbidities after esophagectomy are still common and are a major cause of surgery-related mortality. The relationship between minimally invasive esophagectomy (MIE) and pulmonary morbidities is not clear. The current study aimed to examine the incidence of pulmonary morbidities after MIE and to clarify the associated risk factors. METHODS: Between May 2011 and December 2016, 184 patients underwent MIE for esophageal cancer. Clinical data were prospectively collected and analyzed. Patient- and surgery-related factors, relating to pulmonary complications, were compared between the complicated and uncomplicated cases. RESULTS: The incidence of any pulmonary morbidity following MIE was 17.9%. Univariate analysis showed that past heavy smoking [Brinkman index (BI) ≥ 1000], presence of neoadjuvant therapy, advanced clinical stage (stage III, IV), and intraoperative bleeding ≥ 600 g were candidates for being postoperative pulmonary morbidity risk factors. Multivariate analysis suggested that BI ≥ 1000 and advanced clinical stage were independent risk factors for causing pulmonary morbidities. CONCLUSIONS: Past heavy smoking and advanced stage are independent risk factors for pulmonary morbidities after MIE. When performing MIE for such cases, various preoperative precautions and careful postoperative monitoring are necessary.

Determination of the oxidative stress biomarker urinary 8-hydroxy-2'-deoxyguanosine by automated on-line in-tube solid-phase microextraction coupled with liquid chromatography-tandem mass spectrometry.

A simple and sensitive method for the determination of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage in human urine, was developed using automated on-line in-tube solid-phase microextraction (SPME) coupled with stable isotope-dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS). Creatinine was also analyzed simultaneously to normalize urine volume by the in-tube SPME LC-MS/MS method, and 8-OHdG and creatinine were separated within 3 min using a Zorbax Eclipse XDB-C8 column. Electrospray MS/MS for these compounds was performed on an API 4000 triple quadruple mass spectrometer in the positive ion mode by multiple reaction monitoring. The optimum in-tube SPME conditions were 20 draw/eject cycles of 40 µL of sample at a flow rate of 200 µL/min using a Carboxen 1006 PLOT capillary column as an extraction device. The extracted compounds were easily desorbed from the capillary by passage of the mobile phase, and no carryover was observed. The calibration curve for 8-OHdG using its stable isotope-labeled internal standard was linear in the range of 0.05-10 ng/mL, and the detection limit was 8.3 pg/mL. The intra-day and inter-day precision (relative standard deviations) were below 3.1% and 9.6% (n=5), respectively. This method was applied successfully to the analysis of urine samples without any other pretreatment and interference peaks, with good recovery rates above 91% in spiked urine samples. The limits of quantification of 8-OHdG and creatinine in 0.1 mL urine samples were about 0.32 and 0.69 ng/mL (S/N=10), respectively. This method was utilized to assess the effects of smoking, green tea drinking and alcohol drinking on the urinary excretion of 8-OHdG.