Lipomatous pseudohypertrophy of the pancreas mimicking liposarcoma: A case report.

Lipomatous pseudohypertrophy of the pancreas (LPH) is a rare disease in which the pancreatic parenchyma is replaced with mature adipose tissue. It is an idiopathic condition whose diagnosis is made based on histopathological analyses. Herein, we report the case of a 50-year-old male patient with a lipomatous mass in the head of the pancreas on computed tomography for close examination of a renal tumor. We suspected liposarcoma, and laparotomy was performed. However, histological analyses revealed LPH. Several imaging findings of LPH can enable a noninvasive diagnosis and help its clinical approach.

Right adrenal giant cystic pheochromocytoma: A case report.

A 78-year-old woman was referred to our institution for evaluation and treatment of a mass on her right adrenal gland measuring 12 × 11 × 10 cm. Twenty-four-hour urine analysis revealed a total metanephrine level over 3 times the upper limit of normal. Scintigraphy using 123I-metaiodobenzylguanidine was positive. The mass was resected en bloc by laparotomy after a laparoscopic attempt was unsuccessful. Histopathologic examination revealed a pheochromocytoma of the right adrenal gland, weighing 576 g. The Grading System for Adrenal Pheochromocytoma and Paraganglioma score was 6, and the histology of the tumor was a moderately differentiated type.

Risk factors associated with hypoglycemic events after total pancreatectomy: A nationwide multicenter prospective study in Japan.

BACKGROUND: The number of total pancreatectomy cases have increased worldwide, expanding the need for new insulin products and high-titer pancrelipases. However, the current data that is focused on hypoglycemic events after a total pancreatectomy from large nationwide series are still lacking. This study is aimed to assess the risk factors associated with hypoglycemic events after a total pancreatectomy. METHODS: Data were prospectively collected from 216 consecutive patients who underwent total pancreatectomies between August 2015 and December 2017 from 68 Japanese centers. Of the 216 patients, 166 with a follow-up period of 1 year were analyzed. The risk factors for hypoglycemic events at 6 and 12 months (postoperative months 6 and 12) were investigated based on the results of a nationwide multicenter prospective study. RESULTS: Of the 166 patients, 57 (34%) and 70 (42%) experienced moderate or severe hypoglycemic events or hypoglycemia unawareness on a monthly basis at postoperative months 6 and 12, respectively. Multivariate analysis revealed that body weight loss after surgery ≥0.3 kg and total cholesterol level ≤136 mg/dL at postoperative month 6, and glycated hemoglobin level ≤8.9% and rapid-acting insulin use at postoperative month 12 were independent risk factors for hypoglycemic events after a total pancreatectomy. There were different independent risk factors depending on the postoperative period. CONCLUSION: Patients with body weight loss after surgery, low total cholesterol level, strict glycemic control, and using rapid-acting insulin should be aware of the occurrence of hypoglycemic events after their total pancreatectomy. In order to prevent hypoglycemic events after a total pancreatectomy, we need to consider optimal nutritional and glycemic control according to the postoperative period.

Incidence and risk factors of nonalcoholic fatty liver disease after total pancreatectomy: A first multicenter prospective study in Japan.

BACKGROUND/PURPOSE: In the present study we aimed to prospectively assess the current prevalence and risk factors of nonalcoholic fatty liver disease (NAFLD) after total pancreatectomy (TP). METHODS: Between August 2015 and December 2017, we prospectively collected data from 68 Japanese centers on 148 consecutive patients who underwent TP whose computed tomography (CT) attenuation values were evaluated for 12 months. We defined post-TP NAFLD as a liver parenchyma CT value of less than 40 Hounsfield units (HU). Data on perioperative variables were retrieved from all patients and evaluated using univariate and multivariate analyses to identify the perioperative risk factors of NAFLD. RESULTS: In this prospective cohort study, supplementation of pancreatic exocrine enzymes was provided to all 148 patients, and 97% of them were treated with high-titer pancrelipase (median dosage: 1800 mg) postoperatively. Indeed, 29 patients (19.6%) developed NAFLD within a year after TP. Multivariate analysis revealed that female sex (P = .002), higher body mass index (BMI) (P = .001), and postoperative diarrhea (P = .038) were independent risk factors for post-TP NAFLD. However, post-TP NAFLD ameliorated in 11 patients (37.9%) at 12 months after surgery. CONCLUSIONS: Among patients with risk factors such as female sex, higher BMI, and postoperative diarrhea, attention should be paid to the occurrence of NAFLD after TP.

Pathological eradication of recurrent metastatic renal cell carcinoma with sarcomatoid component by nivolumab plus ipilimumab combination therapy.

Although immuno-oncology combination therapy with nivolumab plus ipilimumab has recently shown a notable antitumor effect for first-line metastatic renal cell carcinoma, the eradication of the disease is extremely rare. Moreover, conventional treatments for renal cell carcinoma show little efficacy in the case of a poor prognostic pathological feature of sarcomatoid dedifferentiation. We report a case of pathological eradication of recurrent metastatic renal cell carcinoma with sarcomatoid component after laparoscopic radical nephrectomy by nivolumab plus ipilimumab combination therapy. A 57-year-old male patient received four cycles of nivolumab plus ipilimumab and thirty cycles of nivolumab for local recurrence and liver metastasis after laparoscopic radical nephrectomy for T3a renal cell carcinoma with sarcomatoid component. He underwent partial hepatectomy for the remaining small hepatic lesion after immuno-oncology therapy. Pathology of the surgical specimen showed no viable cancer cells. The patient was alive with no evidence of disease a year after partial hepatectomy. Our case encourages clinicians to achieve a second cure for patients with recurrent metastatic renal cell carcinoma after radical nephrectomy even though the resected kidney pathology showed sarcomatoid component.

Laparoscopic portal branch ligation of the right caudate lobe concomitant with portal vein embolization for planned right hemihepatectomy in advanced hepatobiliary cancers.

BACKGROUND: The role of ligation of the portal venous branches to the caudate lobe (cPVL) as preparation for planned major hepatectomy is unclear. The aim of this study was to evaluate the efficacy of laparoscopic cPVL (Lap-cPVL) concomitant with transileocolic portal vein embolization of the right portal venous system (rTIPE), namely, Lap-cPVL/rTIPE, for planned right hemihepatectomy (rHx) in advanced hepatobiliary cancer patients. METHODS: Thirty-one patients who underwent rHx after rTIPE with/without Lap-cPVL between March 2013 and March 2020 were enrolled in this study. The Lap-cPVL was performed for the portal branches of the right caudate lobe. RESULTS: Eight of the 31 patients underwent Lap-cPVL/rTIPE. The degree of hypertrophy was significantly increased in Lap-cPVL/rTIPE (19.3%, range 6.5-25.6%) as compared to rTIPE (7.2%, range - 1.1 to 21.2%) (p=0.027). The functional kinetic growth rate was also significantly increased in Lap-cPVL/rTIPE (5.40%, range 2.17-5.97) than that in rTIPE (1.85%, range - 0.22 to 6.45%) (p=0.046). Postoperative liver failure ≧ grade B occurred in 21.7% of patients in rTIPE, while there was no postoperative liver failure ≧ grade B in Lap-cPVL/rTIPE. Mortality rates were zero after rHx in this study. CONCLUSIONS: Lap-cPVL/rTIPE is safe and provides an additional effect on liver hypertrophy in advanced hepatobiliary cancers.

Prediction of postoperative complications and survival after laparoscopic gastrectomy using preoperative Geriatric Nutritional Risk Index in elderly gastric cancer patients.

BACKGROUND: Preoperative nutritional assessment of cancer patients is important to reduce postoperative complications. Several studies have reported the Geriatric Nutritional Risk Index (GNRI) to be useful in assessing underlying diseases and long-term outcomes of hospitalized patients. The present study aimed to evaluate the impact of preoperative GNRI on short- and long-term outcomes in elderly gastric cancer patients who underwent laparoscopic gastrectomy. METHODS: We retrospectively reviewed consecutive patients aged ≥ 65 years who underwent laparoscopy-assisted gastrectomy and had R0 resection for histologically confirmed gastric adenocarcinoma. The cutoff value for preoperative GNRI was determined to be 85.7 based on the incidence of postoperative complications. Patients were categorized into two groups: low GNRI group and normal GNRI group. RESULTS: Univariate analyses of the 303 patients revealed that the incidence of postoperative complications was significantly associated with the American Society of Anesthesiologists Physical Status classification (ASA-PS), C-reactive protein (CRP), GNRI (p < 0.001), and operative procedure. Multivariate analyses revealed that preoperative GNRI (odds ratio [OR] 2.716; 95% confidence interval [CI] 1.166-6.328; p = 0.021) and operative procedure (OR 2.459; 95% CI 1.378-4.390; p = 0.002) were independently associated with the incidence of postoperative complications. Univariate analyses showed that overall survival (OS) was significantly associated with ASA-PS, tumor size, tumor differentiation, pathological tumor node metastasis (TNM) stage, carcinoembryonic antigen (CEA), CRP, GNRI, and postoperative complications. Multivariate analysis demonstrated that ASA-PS (hazard ratio [HR], 3.755; 95% CI 2.141-6.585; p < 0.001), tumor differentiation (HR 1.898; 95% CI 1.191-3.025; p = 0.007), CEA (HR 1.645; 95% CI 1.024-2.643; p = 0.040), and GNRI (HR 2.093; 95% CI 1.105-3.963; p = 0.023) independently predicted OS. CONCLUSION: GNRI is an important predictor of postoperative complications and overall survival in elderly gastric cancer patients. It is a reliable and cost-effective prognostic indicator that should be routinely evaluated.

Accurate prediction of severe postoperative complications after pancreatic surgery: POSSUM vs E-PASS.

BACKGROUND/PURPOSE: Few reports have evaluated the differences in the predictive accuracy between the physiological and operative severity score for the enumeration of mortality and morbidity (POSSUM) and estimation of physiologic ability and surgical stress (E-PASS) in pancreatic surgery. Thus, we evaluated the accuracy and similarity of POSSUM and E-PASS for the prediction of severe postoperative complications (PCs) after pancreatic surgery. METHODS: We enrolled 343 consecutive patients who underwent pancreatic surgery in our department between April 2006 and September 2017. The difference in predictive values of POSSUM and E-PASS for the occurrence of PCs ≥ Clavien-Dindo grade IIIa (PCs-CD ≥ IIIa) was nonparametrically compared. The predictive accuracy and similarity of each tool was examined using the receiver operating characteristic (ROC) curve and linear regression analyses. RESULTS: Forty-five patients developed PCs-CD ≥ IIIa. E-PASS had a significantly higher predictive value for estimating PCs-CD ≥ IIIa occurrence (P = .002) than did POSSUM. The area under the curve value in ROC analysis was significantly higher in E-PASS than in POSSUM (0.643 vs 0.543, P = .014), with a weak positive correlation in the predictive value between E-PASS and POSSUM (R2  = .333, P < .001). CONCLUSION: Estimation of physiologic ability and surgical stress was useful for predicting severe PCs after pancreatic surgery and had a higher accuracy than POSSUM.

Systemic Immune-Inflammation Index Predicts Overall Survival in Patients with Gastric Cancer: a Propensity Score-Matched Analysis.

BACKGROUND: The systemic immune-inflammation index (SII), integrated by peripheral lymphocyte, neutrophil, and platelet counts, is used as an objective biomarker that reflects the balance between host inflammatory and immune response status in cancer patients. Herein, we examined the prognostic significance of SII in gastric cancer patients. METHODS: We retrospectively reviewed data of 415 patients who underwent curative laparoscopic gastrectomy using propensity score-matched (PSM) analysis. The prognostic value of SII was compared between two groups based on SII values: low SII group (SII < 661.9) and high SII group (SII ≥ 661.9). RESULTS: In multivariate analysis, the American Society of Anesthesiologists physical status (ASA-PS) (p < 0.001), tumor differentiation (p = 0.019), pathological stage (p = 0.046), carcinoembryonic antigen (CEA) level (p < 0.001), SII (p = 0.006), and operative procedure (p = 0.009) were independent prognostic factors of overall survival (OS) in the overall PSM cohort. The log-rank test demonstrated that patients with a high SII had significantly worse OS than did those with low SII (p = 0.002). In age-stratified subgroups analysis (< 65/≥ 65 years), multivariate analysis revealed that ASA-PS (p < 0.001), tumor differentiation (p = 0.019), CEA level (p = 0.008), SII (p = 0.013), and operative procedure (p = 0.026) were independent prognostic factors of OS in the elderly group. Similarly, elderly patients with a high SII had significantly worse OS than did those with a low SII (p = 0.009). Meanwhile, SII was not an independent prognostic factor of OS, and no significant association was observed between SII and OS in non-elderly patients. CONCLUSIONS: SII was an independent prognostic indicator in gastric cancer patients, especially in the elderly population.

Hybrid transileocecal portal vein embolization associated with staging laparoscopy for planned major hepatectomy in advanced hepatobiliary cancers.

BACKGROUND: Portal vein embolization (PVE) is widely used to promote the hypertrophy of a future liver remnant (FLR) and reduce posthepatectomy liver failure. The aim of this study was to evaluate the efficacy of transileocecal portal embolization (TIPE) associated with staging laparoscopy (hybrid lap-TIPE) for a planned hepatectomy in advanced hepatobiliary cancers. METHODS: The hybrid lap-TIPE procedure consisted of staging laparoscopy for complete screening of the abdominal cavity with cytoreductive surgery and subsequent TIPE. Data on hybrid lap-TIPE, performed between March 2013 and February 2020, were collected retrospectively. RESULTS: Hybrid lap-TIPE was conducted for 52 patients, and a subsequent TIPE was accomplished in 42 patients (80.8%), since staging laparoscopy detected latent or unresectable factors in 13 patients (25.0%), among which 2 patients with hepatocellular carcinoma and 1 with colorectal liver metastasis received laparoscopic cytoreductive surgery for latent lesions in the FLR. Finally, radical hepatectomy was completed in 36 patients (69.2%), including 3 patients who underwent cytoreductive surgery. The most common operation was an extended right hepatectomy (50.0%), followed by right hepatectomy (30.6%), including 3 hepatopancreatoduodenectomies. The overall morbidity associated with hybrid lap-TIPE and hepatectomy was 7.1% and 41.7%, respectively. The mortality associated with hybrid lap-TIPE and hepatectomy was 0% and 5.6%, respectively. The rates of 2-year survival and 2-year disease-free survival were 64.8% and 61.9%, respectively, after hepatectomy. CONCLUSIONS: Hybrid lap-TIPE is safe and could be a useful treatment option for patients with advanced hepatobiliary cancer because it can help to identify optimal candidates for PVE followed by a planned hepatectomy.

Glasgow prognostic score is a better predictor of the long-term survival in patients with gastric cancer, compared to the modified Glasgow prognostic score or high-sensitivity modified Glasgow prognostic score.

BACKGROUND: Inflammation influences cancer progression by increasing catabolism and impairing nutrient absorption. We compared the prognostic ability of three inflammation-based prognostic scoring systems-the Glasgow prognostic score (GPS), modified GPS (mGPS), and high-sensitivity mGPS (HS-mGPS)-in gastric cancer patients. MATERIALS AND METHODS: We retrospectively examined 434 curatively resected gastric cancer patients to evaluate the prognostic ability of scoring systems for overall survival (OS) and cancer-specific survival (CSS). RESULTS: OS analysis identified the following independent prognostic factors: GPS model: pathological stage (pStage, p < 0.001), carcinoembryonic antigen (CEA, p = 0.004), and GPS 1 (hazard ratio [HR], 1.929; 95% confidence interval [CI], 1.152-3.228; p = 0.013); mGPS model: body mass index (BMI, p = 0.027), pStage (p < 0.001), and CEA (p < 0.001); HS-mGPS model: BMI (p = 0.029), pStage (p < 0.001), and CEA (p = 0.003). mGPS and HS-mGPS were not independent prognostic factors for OS. CSS analysis of the GPS model identified pStage (p < 0.001), CEA (p = 0.015), and GPS 1 (HR; 2.095, 95% CI; 1.025-4.283; p = 0.043) and 2 (HR, 2.812; 95% CI, 1.111-7.116; p = 0.029) as independent prognostic factors; however, mGPS and HS-mGPS were not independent prognostic factors for CSS. Log-rank tests demonstrated significant differences in OS among patients with GPS 0 vs. 1 (p < 0.001) and 0 vs. 2 (p < 0.001) and in CSS among the three GPS (0 vs. 1; p = 0.005, 0 vs. 2; p < 0.001, 1 vs. 2; p = 0.009). CONCLUSIONS: GPS most reliably predicts long-term survival of gastric cancer patients.

Geriatric nutritional risk index as a prognostic marker of pTNM-stage I and II esophageal squamous cell carcinoma after curative resection.

The geriatric nutritional risk index (GNRI) is associated with mortality in several malignancies. We retrospectively analyzed whether the GNRI can predict long-term outcomes in 191 patients with esophageal squamous cell carcinoma (ESCC) after curative esophagectomies by evaluating their cancer-specific survival (CSS). In multivariate analyses, serum albumin (hazard ratio [HR], 2.498; p = 0.0043), GNRI (HR, 1.941; p = 0.0181), pathological tumor-node-metastasis (pTNM) stage (HR, 3.884; p < 0.0001), and tumor differentiation (HR, 2.307; p = 0.0066) were independent prognostic factors for CSS. In pTNM stage I, multivariate analysis identified C-reactive protein (HR, 7.172; p = 0.0483) and GNRI (HR, 5.579; p = 0.0291) as independent prognostic factors for CSS. In univariate analyses in pTNM stages II and III, only low GNRI (p = 0.0095) and low serum albumin levels (p = 0.0119), respectively, were significantly associated with worse CSS. In patients with low GNRI, CSS was significantly worse than in those with normal GNRI (p = 0.0011), especially in pTNM stages I (p = 0.0044) and II (p = 0.0036) groups, but not in stage III group (p = 0.5099). Preoperative GNRI may sort patients into low- or high-risk groups for shorter CSS, especially in those with pTNM stage I and II ESCC.

Comparison of the prognostic value of immunoinflammation-based biomarkers in patients with gastric cancer.

Background: Systemic immune-inflammation index (SII)-comprising platelet, neutrophil, and lymphocyte count-is an objective and reliable biomarker for predicting the prognosis in cancer patients because it comprehensively reflects the balance between host inflammatory and immune responses. In this study, we clarified the prognostic impact of immunoinflammation-based indices, i. e. SII, neutrophil/lymphocyte ratio (NLR), and platelet/lymphocyte ratio (PLR), in gastric cancer patients. Results: In multivariate analysis, the American Society of Anesthesiologists physical status (ASA-PS) (hazard ratio [HR]: 3.366, p < 0.001), tumor differentiation (HR: 1.705, p = 0.020), pathological Tumor, Node, Metastasis (pTNM) stage (HR: 2.160, p = 0.008), and carcinoembryonic antigen (CEA) (HR: 1.964, p = 0.003) were independent prognostic factors for OS in all patients. Further, multivariate analysis revealed that age (HR: 2.088, p = 0.040), ASA-PS (HR: 2.339, p = 0.043), tumor differentiation (HR: 1.748, p = 0.044), and pTNM stage (HR: 2.114, p = 0.024) were independent prognostic factors for OS among patients without inflammation; SII was not a prognostic factor for OS. Meanwhile, body mass index (HR: 5.055, p = 0.011), ASA-PS (HR: 3.403, p = 0.007), and SII (HR: 4.208, p = 0.026) were independent prognostic factors for OS among patients with inflammation. Materials and Methods: We performed a retrospective review of 412 patients who underwent curative laparoscopic gastrectomy. The prognostic value of SII was compared between a low SII group (SII<661.9) and high SII group (SII≥661.9). We analyzed the predictive ability of immunoinflammation-based indices for overall survival (OS) based on a C-reactive protein (CRP) level of 0.5. Conclusions: Compared to NLR and PLR, SII is the most significant prognostic biomarker for OS, especially in gastric cancer patients with inflammation.

Preoperative geriatric nutritional risk index is a useful prognostic indicator in elderly patients with gastric cancer.

BACKGROUND: The geriatric nutritional risk index (GNRI) was developed to evaluate the prognosis in elderly hospitalized patients at risk of malnutrition and related morbidity and mortality. This study aimed to evaluate the relationship between preoperative GNRI and long-term outcomes in elderly gastric cancer patients. MATERIALS AND METHODS: We retrospectively reviewed 297 consecutive patients aged ≥ 65 years who underwent laparoscopic gastrectomy with R0 resection and evaluated their overall survival (OS) and cancer-specific survival (CSS). RESULTS: In the univariate analyses, OS was significantly associated with the American Society of Anesthesiologists Physical Status (ASA-PS), tumor size, tumor differentiation, pathological stage, carcinoembryonic antigen (CEA), C-reactive protein, postoperative complications, and GNRI, whereas in the univariate analyses of CSS, ASA-PS, tumor size, tumor differentiation, pathological stage, CEA, postoperative adjuvant chemotherapy, and GNRI were significantly associated with poor prognosis. In the multivariate analysis, ASA-PS, tumor differentiation, pathological stage, and GNRI were significant independent prognostic factors of OS, whereas ASA-PS, pathological stage, and CEA were significant independent prognostic factors of CSS. CONCLUSIONS: GNRI is significantly associated with OS and CSS in elderly gastric cancer patients and is an independent predictor of OS. It is a simple, cost-effective, and promising nutritional index for predicting OS in elderly patients.

Laparoscopic versus open radical antegrade modular pancreatosplenectomy with artery-first approach in pancreatic cancer.

BACKGROUND: An artery-first approach for pancreatic cancer (PC) is challenging to perform laparoscopically and is mainly performed using an open approach. The aims of this study were to assess the safety and feasibility of laparoscopic radical antegrade modular pancreatosplenectomy (RAMPS) with an artery-first approach (L-aRAMPS) as compared with open aRAMPS (O-aRAMPS) in resectable PC using matched-pair analysis. METHODS: Artery-first approach is an early dissection of the superior mesenteric artery (SMA) from behind the pancreas body as the first surgical step. Data on L-aRAMPS and O-aRAMPS, performed between July 2013 and November 2019, were collected retrospectively. Additionally, the spatial characteristics of the splenic artery were analyzed using computed tomography. RESULTS: Thirty L-aRAMPS and 33 O-aRAMPS for resectable PC were included. After matching, 15 L-aRAMPS were compared with 15 O-aRAMPS. Median intraoperative blood loss and hospital stay were significantly improved in L-aRAMPS compared to O-aRAMPS (30 vs. 220 g, p < 0.001; 12 vs. 16 days, p = 0.049). The overall morbidity was similar in both study groups. The total number of lymph nodes dissected and those harvested from around the SMA and R0 resection was similar in both study groups. We classified the width of the cross section of the pancreas body into three equal parts: the upper, middle, and lower parts of the pancreas; 63% of the splenic artery origin was located in middle and lower parts of the pancreas body. CONCLUSION: L-aRAMPS is technically safe and oncologically feasible to secure favorable surgical outcomes for resectable PC patients.

A multicenter prospective registration study on laparoscopic pancreatectomy in Japan: report on the assessment of 1,429 patients.

BACKGROUND: Prospective studies are needed to understand the safety and feasibility of laparoscopic pancreatectomy. The aim of the present study was to describe laparoscopic pancreatectomy currently undertaken in Japan, using a prospective registration system. METHODS: Patient characteristics and planned operations were registered preoperatively, and then the performed operation and outcomes were reported using an online system. Collected data were also compared between institutions based on their level of experience. This study was registered with UMIN000022836. RESULTS: Available data were obtained from 1,429 patients at 100 Japanese institutions, including 1,197 laparoscopic distal pancreatectomies (LDPs) and 232 laparoscopic pancreatoduodenectomies (LPDs). The rates of completion for planned operations were 92% for LDP and 91% for LPD. Postoperative complication rates after LDP and LPD were 17% and 30%, and 90-day mortality rates were 0.3% and 0.4%, respectively. Shorter operation time, less blood loss, and lower incidence of pancreatic fistula were observed in institutions experienced in LDP. A higher rate of pure laparoscopic procedure and shorter operation time were noted in institutions experienced with LPD. CONCLUSION: LDPs and LPDs are performed safely in Japan, especially in experienced institutions. Our data could support the next challenges in the field of laparoscopic pancreatectomy.

Case of Invasive Carcinoma Derived from Intraductal Papillary Mucinous Neoplasm Negative for GNAS Mutation.

A 70-year-old woman with loss of appetite was referred to our hospital for further examinations. Computed tomography revealed a low density tumor in the body of the pancreas measuring 4 cm in diameter. The main pancreatic duct was dilated on both the head and caudal side of the tumor. Magnetic resonance imaging showed the mass as a low intensity area in T1-weighted and high intensity area in T2-weighted images. Endoscopic retrograde cholangiopancreatography findings indicated that the main pancreatic duct was continuous with the lumen of the tumor. A cytological examination of pancreatic juice showed a class IV tumor. A distal pancreatectomy was performed as a curative resection procedure. The findings of hematoxylin eosin staining and mucus trait led to a diagnosis of invasive cancer derived from an intraductal papillary mucinous neoplasm (IPMN). We also performed sequencing analysis to investigate GNAS and K-RAS mutations in the tumor, though neither the GNAS mutation c602G>A nor K-RAS mutation c35G>A were observed. Cases negative for a GNAS mutation can be considered to have an increased risk of invasive cancer derived from an IPMN.