MANGOU (Miyazaki Advanced New General Surgery of University) Wet Lab Training Relieves Anxiety About Surgical Skills in Surgical Education: A Cross-Sectional Study.

PURPOSE: To increase the number of medical students or residents who want to become surgeons, we must evaluate our program that recruits new young surgeons. METHODS: We planned surgical training programs for medical students and residents that we named the MANGOU (Miyazaki Advanced New General surgery Of University) training project in the Department of Surgery, Miyazaki University, Japan. From January 2016 through December 2022, we asked trainees who attended this training to complete questionnaires to evaluate their interest in surgery, confidence in surgical skills, and training. Scoring of the questionnaire responses was based on a 5-point Likert scale, and we evaluated this training prospectively. RESULTS: Among the 109 trainees participating in this training, 61 answered the questionnaires. Two participants found the training boring, but 59 (96.7%) enjoyed it. All of them answered "Yes" to wanting to participate in the next training. Respective pre- and post-training scores were as follows: confidence in surgical skills, 2.2 ± 1.0 and 3.0 ± 1.0 (p < 0.0001); interest in surgery, 4.2 ± 0.8 and 4.4 ± 0.5 (p = 0.0011); and willingness to become surgeons, 3.9 ± 0.7 and 4.1 ± 0.6 (p = 0.0011). All scores rose after MANGOU training. CONCLUSION: We planned MANGOU surgical wet lab training for medical students and residents that aimed to educate and recruit new surgeons. After joining the MANGOU training, the trainees' anxiety about surgery was reduced, their confidence in performing surgical procedures improved, they showed more interest in surgery, and they increased their motivation to become surgeons.

HMGB2 Promotes De Novo Lipogenesis to Accelerate Hepatocyte Proliferation During Liver Regeneration.

Liver regeneration is a well-orchestrated compensatory process that is regulated by multiple factors. We recently reported the importance of the chromatin protein, a high-mobility group box 2 (HMGB2) in mouse liver regeneration. However, the molecular mechanism remains unclear. In this study, we aimed to study how HMGB2 regulates hepatocyte proliferation during liver regeneration. Seventy-percent partial hepatectomy (PHx) was performed in wild-type (WT) and HMGB2-knockout (KO) mice, and the liver tissues were used for microarray, immunohistochemistry, quantitative polymerase chain reaction (qPCR), and Western blotting analyses. In the WT mice, HMGB2-positive hepatocytes colocalized with cell proliferation markers. In the HMGB2-KO mice, hepatocyte proliferation was significantly decreased. Oil Red O staining revealed the transient accumulation of lipid droplets at 12-24 hr after PHx in the WT mouse livers. In contrast, decreased amount of lipid droplets were found in HMGB2-KO mouse livers, and it was preserved until 36 hr. The microarray, immunohistochemistry, and qPCR results demonstrated that the expression of lipid metabolism-related genes was significantly decreased in the HMGB2-KO mouse livers. The in vitro experiments demonstrated that a decrease in the amount of lipid droplets correlated with decreased cell proliferation activity in HMGB2-knockdown cells. HMGB2 promotes de novo lipogenesis to accelerate hepatocyte proliferation during liver regeneration.

The crucial role of SETDB1 in structural and functional transformation of epithelial cells during regeneration after intestinal ischemia reperfusion injury.

Su (var) 3-9, enhancer of seste, trithorax (SET)-domain bifurcated histone lysine methyltransferase (SETDB1) plays a crucial role in maintaining intestinal stem cell homeostasis; however, its physiological function in epithelial injury is largely unknown. In this study, we investigated the role of SETDB1 in epithelial regeneration using an intestinal ischemia/reperfusion injury (IRI) mouse model. Jejunum tissues were sampled after 75 min of ischemia followed by 3, 24, and 48 h of reperfusion. Morphological evaluations were performed using light microscopy and electron microscopy, and the involvement of SETDB1 in epithelial remodeling was investigated by immunohistochemistry. Expression of SETDB1 was increased following 24 h of reperfusion and localized in not only the crypt bottom but also in the transit amplifying zone and part of the villi. Changes in cell lineage, repression of cell adhesion molecule expression, and decreased histone H3 methylation status were detected in the crypts at the same time. Electron microscopy also revealed aberrant alignment of crypt nuclei and fusion of adjacent villi. Furthermore, increased SETDB1 expression and epithelial remodeling were confirmed with loss of stem cells, suggesting SETDB1 affects epithelial cell plasticity. In addition, crypt elongation and increased numbers of Ki-67 positive cells indicated active cell proliferation after IRI; however, the expression of PCNA was decreased compared to sham mouse jejunum. These morphological changes and the aberrant expression of proliferation markers were prevented by sinefungin, a histone methyltransferase inhibitor. In summary, SETDB1 plays a crucial role in changes in the epithelial structure after IRI-induced stem cell loss.

Clinical Impact of the Charlson Comorbidity Index on the Efficacy of Salvage Photodynamic Therapy Using Talaporfin Sodium for Esophageal Cancer.

Introduction Photodynamic therapy (PDT) is a salvage treatment for local failure after chemoradiotherapy for esophageal cancer. Salvage PDT is the treatment available for vulnerable patients with various comorbidities at risk of salvage esophagectomy. This study assessed the impact of the Charlson comorbidity index (CCI) on the outcomes of salvage PDT using talaporfin sodium (TS) for esophageal cancer. Metohds Consecutive patients with esophageal cancer who underwent salvage TS-PDT from 2016 to 2022 were included in this retrospective study. We investigated the local complete response (L-CR), progression-free survival (PFS) and overall survival (OS) and evaluated the relationship between the CCI and therapeutic efficacy. Results In total, 25 patients were enrolled in this study. Overall, 12 patients (48%) achieved an L-CR, and the 2-year PFS and OS rates were 24.9% and 59.4%, respectively. In a multivariate analysis, a CCI ≥1 (p=0.041) and deeper invasion (p=0.048) were found to be significant independent risk factors for not achieving an L-CR. To evaluate the efficacy associated with comorbidities, we divided the patients into the CCI=0 group (n=11) and the CCI ≥1 group (n=14). The rate of an L-CR (p=0.035) and the 2-year PFS (p=0.029) and OS (p=0.018) rates in the CCI ≥1 group were significantly lower than those in the CCI=0 group. Conclusion This study found that the CCI was negatively associated with the efficacy of salvage TS-PDT for esophageal cancer.

A case of multifocal sclerosis angiomatoid nodular transformations of the spleen occurring after partial splenic infarction with transcatheter arterial embolization for splenic artery aneurysm.

A 48-year-old woman underwent transcatheter arterial embolization (TAE) for a splenic artery aneurysm, which resulted in a partial splenic infarction in the middle lobe. Five years after TAE, a 20-mm diameter mass in the noninfarcted area of the spleen was detected on imaging, which grew to 25 mm in diameter after 6 months. MRI after gadolinium administration showed a 35 × 34 mm mass within the superior pole and 15 × 12 mm mass within the inferior pole. The patient underwent laparoscopic splenectomy and had an uneventful postoperative recovery. No evidence of recurrence was observed during the 2-year follow-up period after surgery. The mass was pathologically confirmed to be sclerosing angiomatoid nodular transformation (SANT) of the spleen. While some studies hypothesize that SANT is a response to vascular injury or trauma, to the best of our knowledge, there have been no previous reports of SANT occurring after procedures directly affecting splenic blood flow. Additionally, multifocal SANTs are reported to be very rare, accounting for only 4.7% of all reported SANTs of the spleen. We highlight a rare course of SANT of the spleen and discuss the possible relationship between blood flow abnormalities and the appearance of SANT.

Protective role of estrogen through G-protein coupled receptor 30 in a colitis mouse model.

Estrogen and its receptors are involved in the pathogenesis of gastrointestinal diseases such as colitis. However, the role of the membrane estrogen receptor G-protein-coupled receptor 30 (GPR30) in colitis is poorly understood. We therefore investigated the effect of estrogen in dextran sulfate sodium (DSS)-induced colitis. Male C57BL/6 mice were administered 1.5% DSS for 5 days and treated with 17ß-estradiol (E2), GPR30 agonist (G1), or GPR30 antagonist (G15) for 8 days. Inflammation grade was evaluated by disease activity index (DAI) and histomorphological score. Colon tissues were immunohistochemically analyzed and revealed high expression of membrane GPR30, histone 3 lysine 36 dimethylation, and lysine 79 trimethylation in normal mouse colon epithelial cells but significantly decreased expression in DSS-treated mice, whereas the expression was partially preserved after treatment with E2 or G1. Colon shortening and DAI were significantly lower in E2- and G1-treated mice compared to DSS-treated mice. Caudal type homeobox 2 (CDX2) expression and cell proliferation differed in normal colon epithelial cells but overlapped in those of DSS-treated mice. Administration of E2 and G1 reduced CDX2 expression and cell proliferation. Altered expression of claudin-2 and occludin were observed in the colonic epithelium of DSS-treated mice, and these changes were significantly lower in the colon of E2- and G1-treated mice. These results indicate that estrogen regulates histone modification, cell proliferation, and CDX2 expression through GPR30, which affects intestinal epithelial barrier function. We conclude that estrogen protects against intestinal epithelial damage through GPR30 by enhancing intestinal epithelial barrier function in DSS-induced colitis in mice.

An unusual presentation of a rare formation of the common hepatic duct and right hepatic artery in a case of pediatric congenital biliary dilatation.

A 15-year-old girl with recurrent upper abdominal pain was diagnosed with congenital biliary dilatation. Abdominal enhanced computed tomography (CT) showed the anterior segmental branch of the right hepatic artery (RHA) running across the ventral aspect of the dilated common hepatic duct (CHD). Laparoscopic extrahepatic dilated biliary duct excision and Roux-en-Y hepaticojejunostomy were planned. Intraoperatively, the dilated CHD was observed to bifurcate into the ventral and dorsal ducts, between which the anterior segmental branch of the RHA crossed through the CHD. The CHD rejoined on the distal side as one duct. We transected the CHD just above the cystic duct. The patency of the ventral and dorsal sides of the bifurcated CHD was confirmed. Laparoscopic hepaticojejunostomy was performed at the distal side of the rejoined CHD, without sacrificing the anterior segmental branch of the RHA. There was no postoperative blood flow impairment in the right hepatic lobe or anastomotic stenosis.

A Preliminary Pathological Evaluation of Extracellular Volume Fraction with Contrast-enhanced Computed Tomography as a Novel Quantitative Parameter of Pancreatic Fibrosis.

Objective The extracellular volume (ECV) calculated based on contrast-enhanced computed tomography (CT) has been reported as a novel imaging parameter reflecting the morphological change of fibrosis in several parenchymal organs. Our retrospective study assessed the validity of the ECV fraction for diagnosing pancreatic fibrosis and the appropriate imaging condition as the "equilibrium phase". Methods In 27 patients undergoing multiphasic CT and subsequent pancreaticoduodenectomy, we investigated pathological fibrotic changes related to the ECV fraction and conducted analyses using the value obtained by subtracting the equilibrium CT value of the portal vein from that of the abdominal aorta (Ao-PVequilibrium) to estimate eligibility of the equilibrium phase. Results In all patients, the ECV fraction showed a weak positive correlation with the collagenous compartment ratio (r=0.388, p=0.045). All patients were divided into two groups - the high-Ao-PVequilibrium group and low-Ao-PVequilibrium group - based on the median value. No significant correlation was found in the high-Ao-PVequilibrium group, whereas a significant correlation was observed in the low-Ao-PVequilibrium group (r=0.566, p=0.035). Conclusion The ECV fraction is a possible predictive factor for histopathological pancreatic fibrosis. In its clinical application, the eligibility of the "equilibrium phase" may affect the diagnostic capability. It will be necessary to verify the imaging conditions in order to improve the accuracy of the diagnosis.

An alternative option of the retroperitoneal laparoscopic approach for limited hepatectomy for recurrent hepatocellular carcinoma at the transected edge after previous hepatectomy.

Laparoscopic hepatectomy is safely performed with minimal invasiveness on patients with recurrent liver tumors after previous hepatectomy. However, it is still difficult to dissect and expose the operative field at the transected edge or plane after open right hepatectomy, even for limited resection by a laparoscopic approach, due to severe adhesion to the surrounding peritoneum or organs. We herein applied the retroperitoneal laparoscopic approach to limited resection of the dorsal surface at the transected edge of Couinaud's segment 6 after previous repeated hepatectomies in a patient with recurrent hepatocellular carcinoma (HCC) by avoiding severe intra-abdominal adhesion. We safely resected recurrent HCC via the retroperitoneal space. This approach is a useful and alternative option for laparoscopy which minimizes the dissecting time and avoids organ injury on the right side of the transected area of the liver after hepatectomy in patients with liver malignancies.

Extracellular Volume Fraction Calculated Using Contrast-Enhanced Computed Tomography as a Biomarker of Oxaliplatin-Induced Sinusoidal Obstruction Syndrome: A Preliminary Histopathological Analysis.

Background: Oxaliplatin (OX)-based chemotherapy induces sinusoidal obstruction syndrome (SOS) in the nontumorous liver parenchyma, which can increase the risk of liver resection due to colorectal liver metastasis (CRLM). The extracellular volume (ECV) calculated from contrast-enhanced computed tomography (CT) has been reported to reflect the morphological change of hepatic fibrosis. The present retrospective study aimed to evaluate the ECV fraction as a predictive factor for OX-induced SOS. Methods: Our study included 26 patients who underwent liver resection for CRLM after OX-based chemotherapy with a preoperative dynamic CT of appropriate quality. We investigated the relationship between the pathological SOS grade and the ECV fraction. Results: Overall, 26 specimens from the patients were graded with the SOS classification of Rubbia-Brandt et al. as follows: grade 0, n = 17 (65.4%); grade 1, n = 4 (15.4%); and grade 2, n = 5 (19.2%). No specimens showed grade 3 SOS. In a univariate analysis, the ECV fraction in grade 0 SOS was significantly lower than that in grade 1 + 2 SOS (26.3 ± 3.4% vs. 30.6 ± 7.0%; P = 0.025). The cutoff value and AUC value of the ECV fraction to distinguish between grades 0 and 1 + 2 were 27.5% and 0.771, respectively. Conclusions: Measurement of the ECV fraction was found to be a potential noninvasive diagnostic method for determining early-stage histopathological sinusoidal injury induced by OX-based chemotherapy.

Questionnaire survey of virtual reality experiences of digestive surgery at a rural academic institute: A pilot study for pre-surgical education.

We developed a prototype VR platform, VECTORS L&M (VLM), aiming to enhance the understanding of digestive surgery for students, interns, and young surgeons by limiting costs. Its efficacy was assessed via questionnaires before implementation in surgical education. The VLM provides nine-minute VR views of surgeries, from both 180- and 360-degree angles. It was created with L.A.B. Co., Ltd. and incorporates surgery videos from biliary malignancy patients. Following VLM development, a survey was conducted among surgeons who had experienced it. Twenty-eight participants (32% of observers) responded to the survey. A majority (81%) reported positive experiences with the VR content and showed interest in VR video production, though some reported sickness. Most respondents were experienced surgeons, and nearly all believed VR was important for medical education with a mean score of 4.14 on a scale of up to 5. VR was preferred over 3D printed models due to its application versatility. Participants expressed the desire for future VR improvements, such as increased mobility, cloud connectivity, cost reduction, and better resolution. The VLM platform, coupled with this innovative teaching approach, offers experiential learning in intraabdominal surgery, effectively enriching the knowledge of students and surgeons ahead of surgical education and training.

Pivotal role of High-Mobility Group Box 2 in ovarian folliculogenesis and fertility.

BACKGROUND: High-Mobility Group Box 1 (HMGB1) and HMGB2 are chromatin-associated proteins that belong to the HMG protein family, and are involved in the regulation of DNA transcription during cell differentiation, proliferation and regeneration in various tissues. However, the role of HMGB2 in ovarian folliculogenesis is largely unknown. METHODS: We investigated the functional role of HMGB1 and HMGB2 in ovarian folliculogenesis and fertilization using C57BL/6 wild type (WT) and HMGB2-knockout (KO) mice. Ovarian tissues were obtained from WT and HMGB2-KO mice at postnatal days 0, 3, 7, and 2, 6 months of age, then performed immunohistochemistry, qPCR and Western blotting analyses. Oocyte fertilization capability was examined by natural breeding and in vitro fertilization experiments. RESULTS: In HMGB2-KO mice, ovary weight was decreased due to reduced numbers of oocytes and follicles. Natural breeding and in vitro fertilization results indicated that HMGB2-KO mice are subfertile, but not sterile. Immunohistochemistry showed that oocytes expressed HMGB2, but not HMGB1, in neonatal and adult WT ovaries. Interestingly, in HMGB2-KO ovaries, a compensatory increase in HMGB1 was found in oocyte nuclei of neonatal and 2-month-old mice; however, this was lost at 6 months of age. CONCLUSIONS: The depletion of HMGB2 led to alterations in ovarian morphology and function, suggesting that HMGB2 plays an essential role in ovarian development, folliculogenesis and fertilization.

Prognostic Value of Repeat Hepatectomy for Hepatocellular Carcinoma Patients.

BACKGROUND/AIM: The potential for repeat hepatectomy has been increasing in hepatocellular carcinoma (HCC) patients. PATIENTS AND METHODS: To assess its significance, we examined the clinical features, surgical records, and survival of 279 HCC patients who underwent hepatectomy as primary treatment. Patients were divided into three groups: single hepatectomy without HCC relapse in 97 patients (Group 1), single hepatectomy with HCC relapse in 133 patients (Group 2) and repeat hepatectomy for HCC relapse in 49 patients (Group 3). Group 3 was divided into three subgroups. Multiple, larger size (>5 cm), and confluent nodular HCC. RESULTS: Child-Pugh B patients were significantly higher in Group 2 (p<0.01). The prevalence of histological vascular involvement was significantly higher in Group 2 than in the other groups (p<0.01). Although Group 2 showed significantly poorer survival (p<0.01), the 10-year overall survival in Groups 1 and 3 was over 70% but not different between groups. The relapse-free survival period was significantly correlated with overall survival, and patients with a cancer-free period of over 36 months showed significantly better 10-year survival rates than those with a period of less than 36 months (p<0.01). Patients undergoing 3 or more repeat hepatectomies also showed good survival periods. CONCLUSION: Careful follow-up and proper decision-making in terms of repeat hepatectomy with multimodal treatments including novel chemotherapies upon assessment of postoperative tumor relapse are important in HCC patients to prolong survival.

Relationship of immunonutritional factor with changes in liver volume after portal vein embolization.

Background: To identify predictors of changes in hepatic volumes after portal vein embolization, we examined the relationship with preoperative nutritional and immunological parameters. Patients and Methods: Ninety-three patients who underwent portal vein embolization were included. The control group comprised 13 patients who underwent right hepatectomy without portal vein embolization. Computed tomographic volumetric parameter was measured for changes in embolized and nonembolized liver. Correlation with various candidates of immunonutritional parameters was examined. Results: Difference in increased liver ratio was 9.1%. C-reactive protein levels significantly increased after portal vein embolization (P < .01), whereas albumin and total cholesterol levels significantly decreased, respectively (P < .01). The C-reactive protein/albumin ratio, prognostic nutritional index, Controlling Nutritional Status score, and modified Glasgow Prognostic Score were significantly different, respectively (P < .01). Prothrombin activity and total cholesterol level significantly correlated with the increased change in nonembolized liver (P < .05). The C-reactive protein and C-reactive protein/albumin ratio after portal vein embolization negatively correlated with hypertrophic ratio (P < .05). By comparing posthepatectomy outcomes between 64 patients undergoing portal vein embolization and 13 who did not, the prevalence of severe complications and mortality in the portal vein embolization group was not different from that in the non-portal vein embolization group. Liver activity at 15 minutes > 0.92 and increased liver volume ≥ 10% tended to correlate with lower prevalence of severe complications. Only increased intraoperative blood loss ≥ 1,500 mL was significantly associated with morbidity and mortality (P < .05). Conclusion: Contrary to our hypothesis, immunonutritional parameters, except C-reactive protein and C-reactive protein/albumin ratio, did not reflect hypertrophy after portal vein embolization. Although it is difficult to predict the hypertrophic degree, the strategy of scheduled hepatectomy should be switched in case of impaired inflammatory status after portal vein embolization.

Using indocyanine green fluorescence in laparoscopic surgery to identify and preserve rare branching of the right hepatic artery in pediatric congenital biliary dilatation.

We describe a laparoscopic surgical technique using indocyanine green (ICG) fluorescence to identify and preserve rare arterial branching associated with pediatric congenital biliary dilatation. Congenital biliary dilatation with pancreaticobiliary maljunction was diagnosed in a 9-year-old girl, who presented with upper abdominal pain. Abdominal enhanced computed tomography (CT) showed that the accessory right hepatic artery (aRHA) branched from the posterior superior pancreaticoduodenal artery (PSPDA) and flowed through the right aspect of the dilated common bile duct (CBD) directly into the right lobe of the liver. We performed laparoscopic dilated biliary duct resection and hepaticojejunostomy, administering ICG intravenously, at a dose of 0.6 mg/kg. The ICG fluorescence overlay mode showed an aRHA running along the right side of the dilated CBD. The aRHA was dissected from the CBD without injury. After finishing the anastomosis, the beating of the aRHA was preserved, confirming that blood flow had been maintained.

Curative remnant total pancreatectomy for recurrent pancreatic acinar cell carcinoma: A case report.

INTRODUCTION AND IMPORTANCE: Acinar cell carcinoma (ACC) of the pancreas is a rare pancreatic cancer subtype (incidence, 0.5-2%) with unclear epidemiology and prognosis. Sometimes, repeat resection including total pancreatectomy is required for recurrence. We report a case of ACC recurring in the remnant pancreatic head after distal pancreatectomy that was successfully cured by remnant pancreatic resection following combination therapy with nab-paclitaxel (nab-PTX) and gemcitabine (GEM). CASE PRESENTATION: A 64-year-old woman was referred for pancreatic tumour treatment. CT revealed a 46-mm tumour in the pancreatic body, and endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) indicated ACC. Distal pancreatectomy was performed, and the final diagnosis was ACC. CT 18 months later showed a 34-mm tumour in the remnant pancreatic head revealed as ACC by EUS-FNA. Portal vein invasion was apparent, so neoadjuvant chemotherapy with nab-PTX and GEM was administered, and remnant pancreatic resection (total pancreatectomy) was performed. No recurrence or distant metastasis was present more than 6 months later. CLINICAL DISCUSSION: Mean survival time for ACC is 18-47 months, and prognosis is good compared with pancreatic ductal adenocarcinoma (PDAC). ACC tends to extend and grow along the main pancreatic duct, which increases the recurrence rate to 50-60%. EUS and EUS-FNA were useful for evaluating tumour extension and diagnosis. Repeat pancreatic resection that included total pancreatectomy was feasible and could be performed safely. CONCLUSION: ACC has a better prognosis than PDAC but with a higher recurrence rate. Aggressive surgical resection that included remnant total pancreatotomy with chemotherapy was useful in treating ACC.

Laparoscopic dome resection for pediatric nonparasitic huge splenic cyst safely performed using indocyanine green fluorescence and percutaneous needle grasper.

INTRODUCTION: In recent years, dome resection, which preserves the splenic immunological function, has been the primary technique used to treat splenic cysts. We herein report a surgical technique using a needle grasper and indocyanine green (ICG) fluorescence to perform dome resection of a huge nonparasitic splenic cyst in a pediatric patient. PATIENT AND SURGICAL TECHNIQUE: A 13-year-old girl was incidentally diagnosed with a splenic cyst during follow-up for scoliosis. Abdominal enhanced computed tomography (CT) showed a 17 × 14 × 14 cm unifocal cyst. Laparoscopic dome resection was planned. The intraoperative findings showed that the spleen was distended, but there was no apparent prominence of the thin cyst wall on the surface of the spleen. An ICG fluorescence camera overlay revealed poor coloration in the thinning area. We punctured the area and aspirated the cyst contents. We grasped the cyst wall with a percutaneous needle grasper and dissected the cyst wall with a vessel sealing system. We placed anti-adhesion agent at the dissection line to prevent recurrence. DISCUSSION: ICG fluorescence was useful for identifying the thinning area of a splenic cyst. The use of a percutaneous needle grasper facilitated the performance of dome resection of a huge splenic cyst in a pediatric patient with minimal invasiveness and an improved cosmetic outcome.

Usefulness of intraoperative contrast-enhanced ultrasonography in laparoscopic enucleation of small pancreatic metastases from renal cell carcinoma: A case report.

Pancreatic metastasis from renal cell carcinoma (RCC) is relatively rare. Surgical resection of the lesion is recommended if no residual tumor remains. Although there is no clear standard for surgical procedures, enucleation can be considered for small lesions. Lesion identification is important for enucleation, and contrast-enhanced ultrasound which takes advantage of the characteristics of hypervascular lesions was useful in a 68-year-old woman who underwent a left nephrectomy for RCC 11 years ago that was pathologically diagnosed as clear cell carcinoma. Recent computed tomography checkup showed a hypervascular tumor of 6 mm in the uncinated process and 10 mm in the pancreatic tail. Endoscopic ultrasonography-guided fine-needle aspiration was performed for the tail lesion, a diagnosis of clear cell carcinoma was made, and laparoscopic enucleation of the pancreatic tumors was performed aided by intraoperative contrast-enhanced ultrasound. The postoperative course was uneventful, and no pancreatic fistula occurred.

An adult case of a retroperitoneal isolated enteric duplication cyst with the imaging changes over time.

BACKGROUND: Adult cases of retroperitoneal isolated enteric duplication cyst (IEDC) are rare, with only 17 case reports in the relevant literature. We herein present a case, which was characterized by changes in intra-cystic density on computed tomography (CT), which was safely resected by laparoscopic surgery. CASE PRESENTATION: The patient was a 60-year-old male who received abdominal CT to investigate the cause of increased serum CA19-9 levels. CT revealed a unilocular cystic mass located in the lower right retroperitoneum. The size increased from 5 to 10 cm in three and a half years and the CT value decreased from 101 Hounsfield Units (HU) to 20 HU. We performed laparoscopic surgical resection, because the possibility that the enlargement of the lesion represented malignant transformation could not be denied. The large cystic mass firmly adhered to the appendix and its mesentery via the retroperitoneum, the appendix was resected en bloc with the cystic lesion. Microscopically, it had no communication with the appendix, and had an intestinal wall structure of muscularis mucosae and muscularis propria. The final pathological diagnosis was IEDC in the retroperitoneal space. There was no histological evidence of malignancy. CONCLUSION: When we encounter a retroperitoneal cystic lesion, we should consider the possibility of malignancy to determine the treatment strategy and perform a careful operation without breaking the cyst wall, irrespective of the preoperative diagnosis.