Endosurgery workshop to improve the confidence of novice pediatric surgeons in performing laparoscopic hepaticojejunostomy.

PURPOSE: This study assessed the efficacy of a high-impact, short-term workshop in honing the laparoscopic hepaticojejunostomy technical skills and self-confidence of novice pediatric surgeons, focusing on vertical needle driving and knot tying. METHODS: Lectures, hands-on sessions, pre- and post-workshop evaluations, and training using porcine models were conducted to refine basic and advanced skills. The "hepaticojejunostomy simulator" was used for comparative analysis of precision in pre- and post-workshop vertical needle driving and knot tying. Participants self-evaluated their skills and confidence on a 5-point scale. RESULTS: After the workshop, eight inexperienced pediatric surgeons demonstrated a significant improvement in hepaticojejunostomy suturing task completion rates and needle-driving precision at the jejunum and hepatic duct. However, the A-Lap Mini Endoscopic Surgery Skill Assessment System indicated no significant improvements in most assessed parameters, except for the full-layer closure score (p = 0.03). However, a significant increase in participants' confidence levels in performing laparoscopic hepaticojejunostomy was observed. CONCLUSION: The workshop augmented technical proficiency and confidence in young pediatric surgeons. The combination of lectures, practical exposure, and model training is an effective educational strategy in pediatric surgical instruction.

Steroid pulse therapy in patients with encephalopathy associated with severe fever with thrombocytopenia syndrome.

Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne infectious disease caused by the SFTS virus (SFTSV). Clinical symptoms of SFTS often involve encephalopathy and other central neurological symptoms, particularly in seriously ill patients; however, pathogenesis of encephalopathy by SFTSV is largely unknown. Herein, we present case reports of three patients with SFTS, complicated by encephalopathy, admitted to Tokushima University hospital: one patient was a 63-year-old man, while the other two were 83- and 86-year-old women. All of them developed disturbance of consciousness around the 7th day post onset of fever. After methylprednisolone pulse therapy of 500 mg/day, all of them recovered without any neurological sequelae. SFTSV genome was not detected in the cerebrospinal fluid of 2 out of the 3 patients that were available for examination. In these patients, disturbance of consciousness seemed to be an indirect effect of the cytokine storm triggered by SFTSV infection. We propose that short-term glucocorticoid therapy might be beneficial in the treatment of encephalopathy during early phase of SFTSV infection.

A new innovative laparoscopic fundoplication training simulator with a surgical skill validation system.

PURPOSE: We developed and validated a specific laparoscopic fundoplication simulator for use with the objective endoscopic surgical skills evaluation system. The aim of this study was to verify the quality of skills of surgeons. MATERIALS AND METHODS: We developed a 1-year-old infant body model based on computed tomography data and reproduced pneumoperitoneum model based on the clinical situation. The examinees were divided into three groups: fifteen pediatric surgery experts (PSE), twenty-four pediatric surgery trainees (PSN), and ten general surgeons (GS). They each had to perform three sutures ligatures for construction of Nissen wrap. Evaluate points are time for task, the symmetry of the placement of the sutures, and the uniformity of the interval of suture ligatures in making wrap. And the total path length and velocity of forceps were measured to assess bi-hand coordination. RESULTS: PSE were significantly superior to PSN regarding total time spent (p < 0.01) and total path length (p < 0.01). GS used both forceps faster than the other groups, and PSN used the right forceps faster than the left forceps (p < 0.05). PSE were shorter with regard to the total path length than GS (p < 0.01). PSE showed most excellent results in the symmetry of the wrap among three groups. CONCLUSION: Our new model was used useful to validate the characteristics between GS and pediatric surgeon. Both PSE and GS have excellent bi-hand coordination and can manipulate both forceps equally and had superior skills compared to PSN. In addition, PSE performed most compact and accurate skills in the conflicted operative space.

Assessment potential of a new suture simulator in laparoscopic surgical skills training.

BACKGROUND: The skills necessary for performing effective laparoscopic suturing are difficult to acquire; as a result, simulators for learning these skills are rapidly becoming integrated into surgical training. The aim of the study was to verify whether a new hybrid simulator has the potential to measure skill improvement in young, less experienced gastroenterological surgeons. MATERIAL AND METHODS: The study included 12 surgeons (median age, 29 (27-38)] years; 11 men (91.7%), one woman (8.3%)) who participated in a two-day laparoscopic training seminar. We used the new simulator before and after the program to evaluate individual performance. Skills were evaluated using five criteria: volume of air pressure leakage, number of full-thickness sutures, suture tension, wound area, and performance time. RESULTS: Air pressure leakage was significantly higher after than before the training (p = .027). The number of full-thickness sutures was significantly higher post-training (p < .01). Suture tension was significantly less post-training (p = .011). Wound opening areas were significantly smaller post-training (p = .018). Performance time was significantly shorter post-training (p = .032). CONCLUSIONS: Our study demonstrated the assessment quality of this new laparoscopic suture simulator.

Evaluation of the 10-year history of a 2-day standardized laparoscopic surgical skills training program at Kyushu University.

PURPOSE: Laparoscopic and open surgical skills differ distinctly from one another. Our institute provides laparoscopic surgical skills training for currently active surgeons throughout Japan. This study was performed to evaluate the effectiveness of our 2-day standardized laparoscopic surgical skills training program over its 10-year history. METHODS: We analyzed the data on trainee characteristics, outcomes of skills assessments at the beginning and end of the program, and self-assessment after 6 months using a questionnaire survey. RESULTS: From January 2004 to December 2013, 914 surgeons completed the 2-day training program. Peaks in postgraduate years of experience occurred at years 2, 8, and 17. Suturing and knot tying times were significantly shorter at the end than beginning of the program (p < 0.001). However, the numbers of misplaced and loose sutures, maximum misplacement distance, and number of injuries to the rubber sheet were significantly higher at the end of the program (p < 0.001). A questionnaire at 6 months post-training revealed significant improvements in the overall skills and forceps manipulation (p < 0.0001) and a significantly shorter mean operation time for laparoscopic cholecystectomy (p < 0.001). CONCLUSION: Our 2-day training program for active Japanese surgeons is thus considered to be effective; however, continued voluntary training is important and further outcomes assessments are needed.

Preoperative simulation regarding the appropriate port location for laparoscopic hepaticojejunostomy: a randomized study using a disease-specific training simulator.

PURPOSE: We verified the appropriate port location for laparoscopic hepaticojejunostomy using a comprehensive laparoscopic training simulator. METHODS: We developed a hepaticojejunostomy model, consist of common hepatic duct and intestine and participants required to place two sutures precisely using two different port locations (A: standard port location, B: modified port location). The order of tasks was randomly determined using the permuted block method (Group I: Task A â†’ Task B, Group II: Task B â†’ Task A). The time for task completion and total number of errors were recorded. In addition, we evaluated the spatial paths and velocity of both forceps. Statistical analyses were performed using a statistical software program. RESULTS: The time for the task, the total error score, and the spatial paths and velocity of both forceps were not significantly different between groups I and II. Furthermore, the port location and order of tasks (group I or group II) did not significantly affect the results. In contrast, there were significant differences in the performance between experts and novices, who were classified as such based on the total number of experienced endoscopic surgeries. CONCLUSION: Preoperative port simulation in advanced surgery using our artificial simulator is feasible and may facilitate minimally invasive surgery for children.

Gastric endoscopic submucosal dissection using novel 2.6-mm articulating devices: an ex vivo comparative and in vivo feasibility study.

BACKGROUND AND STUDY AIMS: The conventional procedure of endoscopic submucosal dissection (ESD) is technically demanding. This study investigated the efficiency of novel articulating devices (maximum diameter 2.6 mm), which can be used with commercially available, standard endoscopes. PATIENTS AND METHODS: In an ex vivo comparative study, eight endoscopists were divided into novices and experienced operators, and performed ESD using new devices and the conventional setup. An in vivo animal experiment was performed by two experts. Procedure times for incision and dissection were recorded, and unit times for circumferential length and area of specimens were calculated. RESULTS: All procedures were successfully completed with en bloc resection. In the ex vivo study, the unit procedure times for incision and dissection by novices were significantly shorter using the new system (P < 0.01 and P < 0.05), whereas there was no significant difference for experienced endoscopists. Perforation occurred during one procedure in which the new system was used. The in vivo experiments were successfully completed without adverse events. CONCLUSIONS: ESD using novel articulating devices was feasible. These devices were able to reduce the procedure time for novices.

Objective assessment of the suture ligature method for the laparoscopic intestinal anastomosis model using a new computerized system.

BACKGROUND: The purpose of this study was to develop a new objective assessment system for the suture ligature method employed in the laparoscopic intestinal anastomosis model. Suturing skills were evaluated objectively using this system. METHODS: This study compared 17 expert surgeons, each of whom had performed >500 laparoscopic procedures, with 36 novice surgeons, each of whom had performed <15 laparoscopic procedures. Each examinee performed a specific skill assessment task using an artificial model that mimics living tissue, which is linked with the Suture Simulator Instruction Evaluation Unit. The model used internal air pressure measurements and image processing to evaluate suturing skills. Five criteria were used to evaluate the skills of participants. RESULTS: The volumes of air pressure leak in the expert and novice groups were 21.13 ± 6.68 and 8.51 ± 8.60 kPa, respectively. The numbers of full-thickness sutures in the expert and novice groups were 2.94 ± 0.24 pairs and 2.47 ± 0.77 pairs, respectively. Suture tensions in the expert and novice groups were 60.99 ± 11.81 and 80.90 ± 16.63 %, respectively. The areas of wound-opening in the expert and novice groups were 1.76 ± 2.17 and 11.06 ± 15.37 mm(2), respectively. The performance times in the expert and novice groups were 349 ± 120 and 750 ± 269 s, respectively. Significant differences between the expert and novice groups for each criterion were observed. The acceptable range of values for each criterion except for the number of full-thickness sutures was statistically defined by the performance of the expert group. CONCLUSIONS: Our system is useful for the quantitative assessment of suturing skill in laparoscopic surgery. We believe that this system is a useful tool for training and assessment of laparoscopic surgeons.

The effect of forceps manipulation for expert pediatric surgeons using an endoscopic pseudo-viewpoint alternating system: the phenomenon of economical slow and fast performance in endoscopic surgery.

PURPOSE: Endoscopic surgery is performed under a horizontal view in comparison to the vertical view that is associated with open surgery. We developed an endoscopic pseudo-viewpoint alternation system with out any scope action. We investigate the effect of this novel system on forceps manipulation among expert pediatric surgeons. METHODS: Six expert pediatric surgeons performed a Nissen wrap in a fundoplication simulator either with or without this system. The constructed Nissen wrap was evaluated. The total path length and the average velocity of the forceps were also analyzed. RESULTS: The times required either with or without this system were 587.5 ± 122.7 and 634.0 ± 212.4 s (p = 0.45), respectively. The total path lengths of right and left forceps either with or without this system were 12,309 ± 2495.5 and 15,726 ± 5649.6 mm (p = 0.07), 10,091 ± 2439.2 and 12,575 ± 5511.1 mm (p = 0.11), respectively. The average velocity of the right and left forceps with or without this system were 26.9 ± 5.29 and 31.6 ± 1.62 mm/s (p = 0.04), 21.6 ± 2.48 and 25.5 ± 6.48 mm/s (p = 0.15), respectively. There was no significance in the suture balance and suture interval. CONCLUSION: The endoscopic pseudo-viewpoint alternation system thus made it possible for expert pediatric surgeons to carry out slow and economical forceps manipulation. These effects make it possible for surgeons to perform safe and precise surgery, thus leading to a shortening of operation time.

Effectiveness of short-term endoscopic surgical skill training for young pediatric surgeons: a validation study using the laparoscopic fundoplication simulator.

PURPOSE: Pediatric surgeons require highly advanced skills when performing endoscopic surgery; however, their experience is often limited in comparison to general surgeons. The aim of this study was to evaluate the effectiveness of endoscopic surgery training for less-experienced pediatric surgeons and then compare their skills before and after training. METHODS: Young pediatric surgeons (n = 7) who participated in this study underwent a 2-day endoscopic skill training program, consisting of lectures, box training and live tissue training. The trainees performed the Nissen construction tasks before and after training using our objective evaluation system. A statistical analysis was conducted using the two-tailed paired Student's t tests. RESULTS: The time for task was 984 ± 220 s before training and 645 ± 92.8 s after training (p < 0.05). The total path length of both forceps was 37855 ± 10586 mm before training and 22582 ± 3045 mm after training (p < 0.05). The average velocity of both forceps was 26.1 ± 3.68 mm/s before training and 22.9 ± 2.47 mm/sec after training (p < 0.1). The right and left balance of suturing was improved after training (p < 0.05). CONCLUSION: Pediatric surgery trainees improved their surgical skills after receiving short-term training. We demonstrated the effectiveness of our training program, which utilized a new laparoscopic fundoplication simulator.

Novel Surgical Skill Evaluation with Reference to Two-handed Coordination.

INTRODUCTION: We evaluated the differences in instrument manipulation skills between expert laparoscopic surgeons and novices. METHODS: Six expert surgeons who had performed more than 500 laparoscopic surgeries and one skilled instructor at Kyushu University Training Center for Minimally Invasive Surgery, and 20 medical students who had experienced no laparoscopic surgery were enrolled. A new skill assessment task was designed using zippers on an unstable, mobile platform in a box trainer. The examinees were asked to close the zippers, while trying to avoid moving the platform. The path lengths of the tips of the instruments and of the platform were measured, and the performance time was also recorded. Surgical skill score was calculated from the correlation between the path lengths of the instruments and that of the platform, in addition to the performance time. RESULTS: The path lengths of the tips of both instruments and of the platform were significantly shorter in the experts than in the novices (all p < 0.05). The performance time was also significantly shorter for experts than novices (p < 0.05). The surgical skill score was significantly higher for experts than novices (p < 0.01). CONCLUSION: The differences in the instrument manipulation skills between expert laparoscopic surgeons and novices could therefore be evaluated using our surgical skill scoring system.

Analysis of hand motion differentiates expert and novice surgeons.

BACKGROUND: The number of operations performed by a surgeon may be an indicator of surgical skill. The hand motions made by a surgeon also reflect skill and level of expertise. We hypothesized that the hand motions of expert and novice surgeons differ significantly, regardless of whether they are familiar with specific tasks during an operation. METHODS: This study compared 11 expert surgeons, each of whom had performed >100 laparoscopic procedures, and 27 young surgeons, each of whom had performed <15 laparoscopic procedures. Each examinee performed a specific skill assessment task, in which instrument motion was monitored using magnetic tracking system. We analyzed the paths of the centers of gravity of the tips of the needle holders and the relative paths of the tips using two mathematical methods of detrended fluctuation analysis and unstable periodic orbit analysis. RESULTS: Detrended fluctuation analysis showed that the exponent in the function describing the initial scaling exponent (α1) differed significantly for experts and novices, being close to 1.0 and 1.5, respectively (P < 0.01). This indicated that the expert group had a greater long-range coherence with an intrinsic sequence and smooth continuity among a series of motions. Likewise, unstable periodic orbit analysis showed that the second period of unstable orbit was significantly longer for experts in comparison with novices (P < 0.01). This demonstrates mathematically that the hands of experts are more stable when performing laparoscopic procedures. CONCLUSIONS: Objective evaluation of hand motion during a simulated laparoscopic procedure showed a significant difference between experts and novices.

Significance of metacognitive skills in laparoscopic surgery assessed by essential task simulation.

BACKGROUND: Metacognition is the knowledge about one's own methods of perceiving, remembering, thinking, and acting. This study determined the significance of metacognitive skills in laparoscopic surgery with the aim of applying the findings in a laparoscopic surgery training program. MATERIAL AND METHODS: Eighteen medical students with no experience in laparoscopic surgery (novice group) and eight expert surgeons who had each performed >100 laparoscopic surgeries (expert group) were enrolled. The examinees in each group performed an evaluation task using a virtual reality simulator and answered questions about the task. RESULTS: The longest performance times, longest path lengths, and most frequent tissue damage occurred at 135° in the novice group and at 180° in the expert group. The greatest recognition of task difficulties, impatience, and irritation occurred at 135° in the novice group and at 180° in the expert group. There were statistically significant correlation coefficients between the instrument path length and task difficulty (metacognition) at 135° (R = 0.74, p = 0.03) and 180° (R = 0.79, p = 0.02) in the expert group, but there were no significant correlations in the novice group. CONCLUSION: We elucidated the significance of metacognitive skills in laparoscopic surgery. A training program should include recognition feedback systems.

Image-guided laparoscopic surgery in an open MRI operating theater.

BACKGROUND: The recent development of open magnetic resonance imaging (MRI) has provided an opportunity for the next stage of image-guided surgical and interventional procedures. The purpose of this study was to evaluate the feasibility of laparoscopic surgery under the pneumoperitoneum with the system of an open MRI operating theater. METHODS: Five patients underwent laparoscopic surgery with a real-time augmented reality navigation system that we previously developed in a horizontal-type 0.4-T open MRI operating theater. RESULTS: All procedures were performed in an open MRI operating theater. During the operations, the laparoscopic monitor clearly showed the augmented reality models of the intraperitoneal structures, such as the common bile ducts and the urinary bladder, as well as the proper positions of the prosthesis. The navigation frame rate was 8 frames per min. The mean fiducial registration error was 6.88 ± 6.18 mm in navigated cases. We were able to use magnetic resonance-incompatible surgical instruments out of the 5-Gs restriction area, as well as conventional laparoscopic surgery, and we developed a real-time augmented reality navigation system using open MRI. CONCLUSIONS: Laparoscopic surgery with our real-time augmented reality navigation system in the open MRI operating theater is a feasible option.

Development of an objective endoscopic surgical skill assessment system for pediatric surgeons: suture ligature model of the crura of the diaphragm in infant fundoplication.

BACKGROUND AND AIM: The Japanese Society of Pediatric Endoscopic Surgeons developed an endoscopic surgical skill qualification (ESSQ) system. However, this is a subjective system we developed and validated an objective skill evaluation system for pediatric surgeons. METHODS: In the ESSQ system, the task operation is laparoscopic fundoplication. Therefore, we set up a suture ligature model of the crura of the diaphragm for infant fundoplication. Examinees were divided into 2 groups, 10 experts and 16 trainees. They had to perform two suture ligatures of the crura using an intracorporeal knot in the box. Evaluation points were time, force on the tissue, suture tension, stitch spacing, equidistance, mean score, and total score. Statistical analysis was performed and p < 0.05 was considered statistically significant. RESULTS: Experts showed better score than trainees in the time score (p < 0.0001), the score for force on the tissue (p < 0.0001), the stitch spacing score (p < 0.05), the equidistance score (p < 0.005), the mean score (p < 0.0001), and the total score (p < 0.0005), respectively. CONCLUSION: The results revealed that the expert group possessed gentle and speedy skills compared with that of the novices. Using this validation study, our established model could be used to objectively evaluate the endoscopic surgical skills of pediatric surgeons.

New detachable occlusion balloon unit for transrectal natural orifice translumenal endoscopic surgery.

INTRODUCTION: Transrectal natural orifice translumenal endoscopic surgery (NOTES) requires a good endoluminal view and adequate intrarectal bacterial clearance in the working area. We developed a new occlusion balloon unit with an easily detachable inflation device, which allows the surgeon a clear working area distal to the balloon. MATERIAL AND METHODS: The effectiveness of the sealing balloon and the extent of macroscopic and histopathological injury to the bowel wall at the site of balloon placement were examined in 12 pigs. RESULTS: The mean time to place and inflate the balloon unit was 12.0 ± 3.5 min, effective air-tightness lasted for 21.0 ± 12.0 min. There was no leakage of dye (methylene blue) past the balloon when pressure was maintained >6.70 ± 0.08 kPa (6.62-6.78 kPa). After gut irrigation, good visibility was maintained in the working area for six hours, and adequate bacterial clearance was maintained for three hours. There were no macroscopic signs of intestinal wall damage at the site of balloon placement. Histopathological examination showed only patchy mucosal damage and submucosal thrombus at the site of balloon placement. CONCLUSION: This newly-developed occlusion balloon unit helps to establish good visibility and adequate bacterial clearance for endoluminal surgical procedures.

Articular cartilage of the posterior condyle can affect rotational alignment in total knee arthroplasty.

PURPOSE: Rotational alignment is important for patellar tracking, ligament balance, and tibiofemoral congruity after total knee arthroplasty (TKA). The posterior condylar axis is often referred to as a rotational alignment landmark. However, articular cartilage wear localized only in the medial condyle might affect the accuracy of rotation, because surgical planning based on CT does not consider the cartilage thickness. The purpose of this study was to clarify whether the cartilage thickness of the posterior condyle affects rotational alignment after TKA. METHODS: A total of 40 osteoarthritis patients waiting for TKA were recruited. MRI of axial sections was performed preoperatively. Scans were controlled to make the cross section perpendicular to the mechanical axis of the femur on the coronal plane and to the tangent line of the distal femur on the sagittal plane, so that the surgical section of the actual femur could be simulated. The condylar twist angle (CTA) was measured with and without articular cartilage. The cartilage thickness on the medial and lateral posterior condyles was surveyed in both MRI images and surgical specimens. RESULTS: The CTA without cartilage (6.8 ± 2.0°) was significantly larger than the CTA with cartilage (5.2 ± 2.0°) (P < 0.01), and 12 knees (30%) demonstrated differences of more than 2 degrees. The cartilage depicted in MRI showed almost the same thickness as the actual specimens and was significantly thicker on the lateral condyles. CONCLUSIONS: Surgical planning for TKA not considering articular cartilage might lead to the externally rotated malposition of the femoral implant. LEVEL OF EVIDENCE: II.

Augmented reality navigation system for laparoscopic splenectomy in children based on preoperative CT image using optical tracking device.

PURPOSE: In endoscopic surgery, limited views and lack of tactile sensation restrict the surgeon's abilities and cause stress to the surgeon. Therefore, an intra-operative navigation system is strongly recommended. We developed an augmented reality (AR) navigation system based on preoperative CT imaging. The purpose of this study is to evaluate the usefulness, feasibility, and accuracy of this system using laparoscopic splenectomy in children. METHODS: Volume images were reconstructed by three-dimensional (3D) viewer application. We used an optical tracking system for registration between volume image and body surface markers. The AR visualization was superimposed preoperative 3D CT images onto captured laparoscopic live images. This system was applied to six cases of laparoscopic splenectomy in children. To evaluate registration accuracy, distances from the marker position to the volume data were calculated. RESULTS: The operator recognized the hidden vascular variation of the splenic artery and vein, accessory spleen, and pancreatic tail by overlaying an image onto a laparoscopic live image. The registration accuracy of six cases was 5.30 ± 0.08, 5.71 ± 1.70, 10.1 ± 0.60, 18.8 ± 3.56, 4.06 ± 1.71, and 7.05 ± 4.71. CONCLUSION: This navigation system provides real-time anatomical information, which cannot be otherwise visualized without navigation. The registration accuracy was acceptable in clinical operation.

The impact of interprofessional communication through ICT on health outcomes of older adults receiving home care in Japan - A retrospective cohort study.

Background: Information communication technology (ICT) is crucial to modern communication and information sharing. Effective interprofessional collaboration is essential in the care of elderly people. However, little is known about the effects of ICT on care provision for elderly people in a home setting. This retrospective cohort study examines the impact of interprofessional collaboration using ICT on the health outcomes of elderly home care patients. Methods: The Team® mobile application promotes cooperation in local medical health care. It enables providers to obtain and share patient information within a single, cloud-based platform. We collected and analyzed data from 554 patients from Nagaoka (Niigata prefecture, Japan) who received home care services from 2015 to 2020. We calculated the cumulative hazard ratio (HR) of death or admission to a hospital or nursing home for patients whose information was shared among different professions using the platform, and for those whose information was not shared. We used a Cox proportional hazards model, adjusted for covariates, and applied propensity score matching. Results: The average age of the study population was 83.5 years; the median follow-up period was 579.0 days. The risk of death or admission to a hospital or nursing home significantly decreased in the information-shared group, compared with the control group (adjusted HR: 0.47 [p < 0.01]). Significance remained after propensity score matching (HR: 0.58; p = 0.01). Conclusions: Interprofessional collaboration using ICT may reduce the risk of death or admission to a hospital or nursing home among elderly home care patients in Japan.

Acute undifferentiated leukemia limited to neck lymph nodes and a large mediastinal mass.

In the 2016 update of the World Health Organization (WHO) classification of myeloid neoplasms, acute undifferentiated leukemia (AUL) was defined by a lack of lineage-specific markers. AUL has very poor prognosis and no established therapies due to its rarity. We report a case of a 31-year-old man with AUL who showed complete molecular response to an acute lymphoblastic leukemia (ALL)-based regimen and received allogeneic hematopoietic stem cell transplantation. The patient's blast cells were CD7-positive and localized to lymph nodes in the neck and to a large mediastinal mass; there was also rearrangement of the T-cell receptor delta locus. Although the tumor showed characteristics of T-cell lymphoblastic lymphoma, it was categorized as AUL based on WHO classification. This case suggests that a high-intensity conditioning regimen could be effective for rare cases of AUL that present only in the extramedullary mass, and chemotherapy for AUL should be selected based on the characteristics of the blasts.