Background: Ameloblastic carcinoma is a malignant form of ameloblastoma and a very rare odontogenic tumor. We report a case of ameloblastic carcinoma that occurred after removal of a right-sided mandibular dental implant.Case presentation A 72-year-old female patient visited her family dentist with a complaint of pain around a lower right implant placed 37 years previously. Although the dental implant was removed with the diagnosis of periimplantitis, the patient experienced dullness of sensation in the lower lip and was followed up by her dentist, but after no improvement. She was referred to a highly specialized institution where she was diagnosed with osteomyelitis and treated the patient with medication; however, there was no improvement. In addition, granulation was observed in the same area leading to a suspicion of malignancy, and the patient was referred to our oral cancer center. The diagnosis of squamous cell carcinoma was made after a biopsy at our hospital. Under general anesthesia, the patient underwent mandibulectomy, right-sided neck dissection, free flap reconstruction with an anterolateral thigh flap, immediate reconstruction with a metal plate, and tracheostomy. Histological analysis of the resected specimen on hematoxylin and eosin staining showed structures reminiscent of enamel pulp and squamous epithelium in the center of the tumor. The tumor cells were highly atypical, with nuclear staining, hypertrophy, irregular nuclear size, and irregular nuclear shape, all of which were suggestive of cancer. Immunohistochemical analysis showed that Ki-67 was expressed in more than 80% of the targeted area, and the final diagnosis was primary ameloblastic carcinoma. Conclusion After reconstructive flap transplantation, occlusion was re-established using a maxillofacial prosthesis.The patient remained disease-free at the 1-year 3-month follow-up.

Thoracic endovascular aortic repair (TEVAR) is valuable in the treatment of type B aortic dissection. An isolated left vertebral artery (ILVA) is a common anomaly of the aortic arch. The ILVA is covered during TEVAR in specific cases; however, whether the ILVA should be reconstructed in all cases remains controversial. We report a case of TEVAR performed for chronic aortic dissection in a patient with an ILVA. A 57-year-old woman with an ILVA had a type B acute aortic dissection one year prior to presentation and underwent TEVAR owing to dilation of an ulcer-like projection. We performed ILVA-left common carotid artery (LCCA) anastomosis and LCCA-left axillary artery bypass prior to TEVAR using our usual procedure. The postoperative course was favorable without any major complication. ILVA reconstruction may reduce the incidence of postoperative stroke and spinal cord injury. Usually, an ILVA is easily accessible through the supraclavicular approach, and the anatomical position of the vessel facilitates ILVA-LCCA anastomosis. ILVA reconstruction requires additional features and further consideration.

Endoscopic resection (ER) is widely performed for early gastric cancer (EGC) with a negligible risk of lymph node metastasis (LNM) in Eastern Asian countries. In particular, endoscopic submucosal dissection (ESD) leads to a high en bloc resection rate, enabling accurate pathological evaluation. As undifferentiated EGC (UD-EGC) is known to result in a higher incidence of LNM and infiltrative growth than differentiated EGC (D-EGC), the indications for ER are limited compared with those for D-EGC. Previously, clinical staging as intramucosal UD-EGC ≤2 cm, without ulceration, was presented as ‘weakly recommended’ or ‘expanded indications’ for ER in the guidelines of the United States, Europe, Korea, and Japan. Based on promising long-term outcomes from a prospective multicenter study by the Japan Clinical Oncology Group (JCOG) 1009/1010, the status of this indication has expanded and is now considered ‘absolute indications’ in the latest Japanese guidelines published in 2021. In this study, which comprised 275 patients with UD-EGC (cT1a, ≤2 cm, without ulceration) treated with ESD, the 5-year overall survival (OS) was 99.3% (95% confidence interval, 97.1%–99.8%), which was higher than the threshold 5-year OS (89.9%). Currently, the levels of evidence grades and recommendations for ER of UD-EGC differ among Japan, Korea, and Western countries. Therefore, a further discussion is warranted to generalize the indications for ER of UD-EGC in countries besides Japan.

Endoscopic resection (ER) is widely utilized as a minimally invasive treatment for upper gastrointestinal tumors; however, complications could occur during and after the procedure. Post-ER mucosal defect leads to delayed perforation and bleeding; therefore, endoscopic closure methods (endoscopic hand-suturing, the endoloop and endoclip closure method, and over-the-scope clip method) and tissue shielding methods (polyglycolic acid sheets and fibrin glue) are developed to prevent these complications. During duodenal ER, complete closure of the mucosal defect significantly reduces delayed bleeding and should be performed. An extensive mucosal defect that comprises three-quarters of the circumference in the esophagus, gastric antrum, or cardia is a significant risk factor for post-ER stricture. Steroid therapy is considered the first-line option for the prevention of esophageal stricture, but its efficacy for gastric stricture remains unclear. Methods for the prevention and management of ER-related complications in the esophagus, stomach, and duodenum differ according to the organ; therefore, endoscopists should be familiar with ways of preventing and managing organ-specific complications.

Background/Aims: Endoscopic biliary drainage is the gold standard treatment for cholangitis. The two methods of biliary drainage are endoscopic biliary stenting and nasobiliary drainage. A novel integrated outside biliary stent and nasobiliary drainage catheter system (UMIDAS NB stent; Olympus Medical Systems) was recently developed. In this study, we evaluated the efficacy of this stent in the treatment of cholangitis caused by common bile duct stones or distal bile duct strictures. Methods: We conducted a retrospective pilot study by examining the medical records of patients who required endoscopic biliary drainage for cholangitis due to common bile duct stones or distal bile duct strictures, and who were treated with a UMIDAS NB stent, between December 2021 and July 2022. Results: Records of 54 consecutive patients were reviewed. Technical and clinical success rates were 47/54 (87.0%) and 52/54 (96.3%), respectively. Adverse events were observed in 12 patients, with six patients experiencing pancreatitis as an adverse event, following endoscopic retrograde cholangiopancreatography (ERCP). Regarding late adverse events, five cases of biliary stent migration into the bile duct were observed. Disease-related death occurred in one patient. Conclusions The outside-type UMIDAS NB stent is an efficacious new method for biliary drainage and can be applied to many indications.

Objective: In the treatment of patients with schizophrenia, pro re nata (PRN) drugs are commonly prescribed for medical indications such as agitation, acute psychiatric symptoms, insomnia, and anxiety. However, high-quality evidence supporting the use of PRN medications is lacking, and these drugs are administered on the basis of clinical experience and habits. Therefore, the actual use of psychotropic PRN drugs and its influence on the patients’ outcomes need to be investigated. Methods: This study included 205 patients who underwent inpatient treatment for schizophrenia. We investigated the prescription of psychotropic drugs before admission and at discharge, as well as the dosing frequency of PRN drugs during hospitalization. We also examined the influence of psychotropic PRN drug use on hospitalization days, antipsychotic polypharmacy, and readmission rates. Results: Patients who used psychotropic PRN drugs during hospitalization had significantly longer hospitalization days (p = 7.5 × 10−4 ) and significantly higher rates of antipsychotic polypharmacy (p = 2.4 × 10−4 ) at discharge than those who did not use psychotropic PRN drugs. Moreover, a higher number of psychotropic PRN drugs used per day was associated with higher readmission rates within 3 months of discharge (p = 4.4 × 10−3 ). Conclusion Psychotropic PRN drug use is associated with prolonged hospitalization, antipsychotic polypharmacy, and increased readmission rates in inpatients with schizophrenia. Therefore, psychiatric symptoms should be stabilized with regularly prescribed medications without the extensive use of psychotropic PRN drugs. Moreover, a system for monitoring and reexamining PRN drug use needs to be established.

Nephroblastomatosis (NBM) is a precursor of Wilms tumor. We herein report a case in which Wilms tumor was initially suspected and the affected kidney was removed.The tumor was subsequently diagnosed as intralobar NBM and a favorable outcome was achieved with postoperative chemotherapy. A 2-year-old boy who presented with gross hematuria was found to have an enlarged left kidney with hydronephrosis.Needle biopsy of the left kidney suggested Wilms tumor and left nephrectomy was performed. The tumor was histopathologically diagnosed as intralobar NBM.Although NBM is regarded as a precancerous lesion, a definite treatment plan has not yet been established. In the present case, we used a similar chemotherapy regimen to that for Wilms tumor. Eight years after the completion of chemotherapy, Wilms tumor has not developed or recurred. Appropriate management plans need to be developed by accumulating similar cases.

Background/Aims: This study aimed to assess the efficacy of a novel aerosol-exposure protection (AP) mask in preventing coronavirus disease in healthcare professionals during upper gastrointestinal endoscopy and to evaluate its clinical feasibility. Methods: In Study 1, three healthy volunteers volitionally coughed with and without the AP mask in a cleanroom. Microparticles were visualized and counted with a specific measurement system and compared with and without the AP mask. In Study 2, 30 patients underwent endoscopic resection with the AP mask covering the face, and the SpO2 was measured throughout the procedure. Results: In Study 1, the median number of microparticles in volunteers 1, 2, and 3 with and without the AP mask was 8.5 and 110.0, 7.0 and 51.5, and 8.0 and 95.0, respectively (p<0.01). Using the AP mask, microparticles were reduced by approximately 92%. The median distances of microparticle scattering without the AP mask were 60, 0, and 68 in volunteers 1, 2, and 3, respectively. In Study 2, the mean SpO2 was 96.3%, and desaturation occurred in three patients. Conclusion The AP mask could provide protection from aerosol exposure and can be safely used for endoscopy in clinical practice.

Background/Aims: Probe-based confocal laser endomicroscopy (pCLE) requires the administration of intravenous (IV) fluorescein. This study aimed to determine the optimal dose of IV fluorescein for both upper and lower gastrointestinal (GI) tract pCLE. Methods: Patients 20 to 79 years old with gastric high-grade dysplasia (HGD) or colorectal neoplasms (CRNs) were enrolled in the study. The dose de-escalation method was employed with five levels. The primary endpoint of the study was the determination of the optimal dose of IV fluorescein for pCLE of the GI tract. The reduced dose was determined based on off-line reviews by three endoscopists. An insufficient dose of fluorescein was defined as the dose of fluorescein with which the pCLE images were not deemed to be visible. If all three endoscopists determined that the tissue structure was visible, the doses were de-escalated. Results: A total of 12 patients with gastric HGD and 12 patients with CRNs were enrolled in the study. Doses were de-escalated to 0.5 mg/kg of fluorescein for both non-neoplastic duodenal and colorectal mucosa. All gastric HGD or CRNs were visible with pCLE with IV fluorescein at 0.5 mg/kg. Conclusions In the present study, pCLE with IV fluorescein 0.5 mg/kg was adequate to visualize the magnified structure of both the upper and lower GI tract.