[FOLFIRI plus RAM Therapy in Later Line of Unresectable Colorectal Cancer].

FOLFIRI plus ramucirumab(RAM)therapy has been reported to be effective and safe in the RAISE trial as second-line treatment for unresectable colorectal cancer. It is hypothesized that RAM may be effective in patients with PD treated with FOLFIRI plus bevacizumab(Bev)due to different mechanism of action from that of Bev, which is also an angiogenesis inhibitor. From January 2017 to December 2021, we conducted a retrospective study of 6 patients who had PD with 5-FU, oxaliplatin, irinotecan, or Bev as first or second-line treatment at our institution and who received FOLFIRI plus RAM in later line treatment. The 6 cases consisted of 3 patients in the third-line treatment, 1 patient in the fourth-line treatment, and 2 patients in the sixth-line treatment. The anti-tumor effect was PD in all cases in the third-line and fourth-line treatment, but the 2 patients of sixth-line treatment were controlled diseases.

[A Case Report-A Successful Case of Distal Pancreatectomy with En Bloc Celiac Axis Resection for Locally Advanced Pancreatic Cancer with an Aberrant Right Hepatic Artery].

In cases of pancreatic cancer with anatomical variations of the hepatic artery, it is important to evaluate the hemodynamics of each case for surgical indication. We report the case of a 68-year-old man with locally advanced pancreatic cancer and an aberrant right hepatic artery who underwent distal pancreatectomy with celiac axis resection(DP-CAR). He was admitted to our institute due to abdominal discomfort. A CT scan showed pancreatic cancer invading the common hepatic artery. He underwent chemoradiotherapy with a diagnosis of locally advanced pancreatic cancer. After the tumor downstaging, we performed DP-CAR, which included a gastroduodenal artery and a proper hepatic artery resection. Even though delayed gastric emptying was observed after the operation, he was discharged on postoperative day 36.

SIRT3-Mediated SOD2 and PGC-1α Contribute to Chemoresistance in Colorectal Cancer Cells.

BACKGROUND: Anticancer drugs generate excessive reactive oxygen species (ROS), which can cause cell death. Cancer cells can resist this oxidative stress, but the mechanism of resistance and associations with chemoresistance are unclear. Here, we focused on Sirtuin 3 (SIRT3), a deacetylating mitochondrial enzyme, in oxidative stress resistance in colorectal cancer (CRC). METHODS: To evaluate SIRT3-related changes in mitochondrial function, ROS (mtROS) induction, and apoptosis, we used the human CRC cell lines HT29 and HCT116 transfected with short-hairpin RNA targeting SIRT3 and small interfering RNAs targeting superoxide dismutase 2 mitochondrial (SOD2) and peroxisome proliferator-activated receptor γ coactivator-1 (PGC-1α). In 142 clinical specimens from patients with CRC, we also assessed the association of SIRT3 protein levels (high/low) and prognosis. RESULTS: SIRT3 expression correlated with mtROS generation and apoptosis induction in cells treated with anticancer agents. Suppressing SIRT3 increased mtROS levels and cell sensitivity to anticancer agents. SIRT3 knockdown decreased SOD2 expression and activity, and suppressing SOD2 also improved sensitivity to anticancer drugs. In addition, SIRT3 was recruited with PGC-1α under oxidative stress, and suppressing SIRT3 decreased PGC-1α expression and mitochondrial function. PGC-1α knockdown decreased mitochondrial activity and increased apoptosis in cells treated with anticancer drugs. In resected CRC specimens, high vs low SIRT3 protein levels were associated with significantly reduced cancer-specific survival. CONCLUSIONS: SIRT3 expression affected CRC cell chemoresistance through SOD2 and PGC-1α regulation and was an independent prognostic factor in CRC. SIRT3 may be a novel target for CRC therapies and a predictive marker of sensitivity to chemotherapy.

Factors predictive of high-output ileostomy: a retrospective single-center comparative study.

PURPOSE: High-output syndrome (HOS) is a complication of ileostomy, which can affect quality of life significantly; however, its exact cause remains unknown. The aim of this study was to establish the frequency, as well as the preoperative and intraoperative factors predictive of HOS. METHODS: The subjects of this study were 164 consecutive patients who underwent colorectal cancer surgery with ileostomy construction at our institute between January, 2011 and August, 2018. Thirteen patients with postoperative complications reported as causes of HOS, including intraperitoneal abscess, paralytic ileus, and outlet obstruction, were excluded. We used a logistic regression analysis to identify the factors predictive of HOS. RESULTS: HOS developed in 36 of the 151 patients (23.8%). There were significantly more diabetic patients in the HOS group (P = 0.03), but other patient factors such as age, gender, body mass index, and use of daily laxatives were not significantly different between the groups. The HOS group had significantly more cases of total proctocolectomy (P = 0.04), but other surgical factors such as operative time, and blood transfusion were not significantly different between the two groups. CONCLUSIONS: These results indicate that diabetes and total proctocolectomy are preoperative predictors of HOS, allowing for the possibility of early intervention via post-surgical treatment.

[Clinical Significance of Placing a PEG during Chemoradiotherapy for Advanced Esophageal Cancer].

BACKGROUND: Unresectable advanced esophageal cancer is often treated with chemotherapy or chemoradiotherapy(CRT). Nutritional disorders caused by dysphagia may lead to a poor prognosis. Placing a PEG before starting CRT for advanced esophageal cancer may maintain better nutritional status. PURPOSE: The purpose of this study is to evaluate the clinical significance of placing a PEG before starting CRT for advanced esophageal cancer. RESULTS: Fifty-one cases were evaluated, 22 PEG (+) and 29 PEG (-). The rate of a CRT was better in PEG (+) than PEG (-) cases (91% vs 79%). Infection around the PEG was the only type of complication, affecting 5%. CONCLUSION: PEG feeding during CRT is important in the development of effective treatments for unresectable advanced esophageal cancer.

[A case of synchronous sigmoid cancer and ureter cancer].

A 78-year-old-man visited a nearby doctor for treatment of hepatitis C and high blood pressure.He was diagnosed with right hydronephrosis by abdominal echography conducted in follow-up of hepatitis C treatment in November 2011; he was then introduced to our hospital for close inspection and medical treatment.We observed wall hyperplasia and narrowing of the lumen in the central sigmoid part by contrast-enhanced computed tomography (CT).The right ureter at the L4/5 level showed wall hyperplasia and a deep color, and the right ureter, renal pelvis, and calix were expanded on the head side. By examination for CF, we observed a type 2 lesion in the sigmoid colon, and a biopsy showed well-differentiated adenocarcinoma. Based upon these findings, he was diagnosed with synchronous sigmoid colon cancer (cT4aN0M0, cStage II) and ureter cancer (cT2N0M0, cStage II); we performed laparotomy sigmoidectomy(D3 dissection)and full extraction of the right kidney urinary tract (lymph node dissection in front of the vena cava, the latter outside and between the aorta and vena cava). The postoperative course was particularly uneventful, and the patient was discharged from the hospital on day 38 after the operation. More than 2 years after the surgery, the patient exhibits no sign of sigmoid colon cancer or ureter cancer recurrence.

Salvage surgery for pouch-related complication after ileal pouch-anal anastomosis: a report of two cases.

BACKGROUND: Pouch-related complications (PRCs), such as pelvic abscesses and perianal complex fistulas, can occur after ileal pouch-anal anastomosis (IPAA) in ulcerative colitis (UC). They are often difficult to treat and require salvage surgery. We report two cases of PRC associated with fistulas. CASE PRESENTATION: First case: A 38-year-old man was diagnosed with UC at age 26 years. Four months after the diagnosis of UC, the patient underwent hand-assisted laparoscopic restorative proctocolectomy, IPAA, and ileostomy for acute fulminant UC. Two years after the closure of the ileostomy, the patient developed a perianal abscess and underwent ileostomy reconstruction. He was referred to our department at 35 years of age, because his symptoms did not improve despite repeated seton drainage of a complicated perineal fistula. We diagnosed PRC with a pelvic abscess and complicated pouch fistula and performed salvage surgery. This diagnosis was revised to Crohn's disease. SECOND CASE: A 50-year-old man was diagnosed with UC at age 18 years and was administered high doses of steroids; however, his symptoms did not improve. He underwent restorative proctocolectomy, IPAA, and ileostomy at another hospital. The ileostomy was closed, and his condition stabilized thereafter. At 35 years of age, perianal pain developed, and he was diagnosed with a complicated pouch-perineal fistula. A fistula was observed near the staple line of the ileal end closure on the head side of the pouch. Reconstruction of the ileostomy and seton drainage were performed; however, his symptoms did not improve, and he was referred to our hospital. We diagnosed PRC with a pelvic abscess and a complicated pouch fistula and performed salvage surgery. The resected specimen showed strictures in two locations: at the oral site of the afferent limb (at the pouch) and at the IPAA. Both patients returned to society and are currently outpatients. CONCLUSIONS: We encountered two cases of PRC after IPAA that did not improve with seton drainage or ileostomy. Pouch resection was performed after considering the patient's quality of life and reintegration into society.

Venous Thromboembolism Following Lateral Lymph Node Dissection for Rectal Cancer.

BACKGROUND/AIM: Postoperative venous thromboembolism (VTE) is a well-recognized complication that leads to morbidity and mortality. Lateral lymph node dissection (LLND) for rectal cancer is thought to potentially increase the risk of VTE due to its technical complexity. However, the relationship between LLND and VTE remains inadequately understood. The aim of this study was to elucidate the impact of LLND on the incidence of postoperative VTE. PATIENTS AND METHODS: This is a retrospective analysis of patients who underwent rectal cancer resection between 2010 and 2018 to identify the risk factors associated with postoperative VTE. Patients were divided into two groups: those who underwent surgery with LLND (LLND+ group) and those who underwent surgery without LLND (LLND- group). RESULTS: A total of 543 patients were enrolled in this study, and 113 patients underwent surgery for rectal cancer with LLND. VTE developed in 8 patients (1.47%), with the incidence rates being 4.42% in the LLND+ group and 0.69% in the LLND- group, respectively (p=0.012). Three of 8 patients had developed severe postoperative complications, and the other two patients needed intraoperative repair of the iliac vein during LLND procedure. Multivariate analysis identified the incidence of postoperative complications and LLND as the independent risk factors of VTE. CONCLUSION: Patients undergoing rectal cancer surgery with LLND should be closely monitored for signs of VTE.

[Jejunostomy catheter feeding during postoperative chemotherapy for Stage IV gastric cancer].

Chemotherapy followed by surgery for Stage IV gastric cancer with passage obstruction poses a problem in terms of poor postoperative nutritional status. By maintaining an adequate postoperative nutrition status with jejunostomy catheter feeding, chemotherapy may possibly be continued. We treated 40 cases of Stage IV gastric cancer with passage obstruction from January 2008 to December 2011. In every case, jejunostomy catheter feeding tubes were placed during gastric cancer surgery. We performed 13 total gastrectomies, 20 distal gastrectomies, and 7 gastrojejunal bypass surgeries. Tube obstruction in 4 cases( 10%) and tube deviation in 1 case( 2.5%) occurred during the tube feeding period. Chemotherapy could be resumed in 37 cases( 92.5%), and the duration of chemotherapy was 330 days( range, 41-721). In cases of Stage IV gastric cancer, patients are obliged to start postoperative chemotherapy at an unstable period. By starting jejunal catheter feeding at an early stage after surgery, improved results could be expected in terms of shortening of the hospital stay or continuation of chemotherapy.

[A case of primary undifferentiated carcinoma of the duodenum].

We report a case of undifferentiated carcinoma of the duodenum. A 40-year-old man was referred to our hospital as he experienced upper abdominal pain that had persisted for half a year. Gastrointestinal endoscopy revealed a semicircular tumor in the duodenum. Enhanced computed tomography( CT) revealed that the tumor had not invaded the adjacent tissues, and lymph node metastases were not detected. Biopsy indicated a diagnosis of Group V cancer. Because the tumor was diagnosed as primary duodenal cancer, pancreatoduodenectomy and lymphadenectomy were performed. Histopathological examination revealed the presence of variant cells with irregular cores; we then diagnosed the tumor as undifferentiated cancer of the duodenum. No lymph node metastasis was detected microscopically. This patient has remained well without recurrence for 17 months since the operation. Undifferentiated carcinoma of the duodenum is rare, as only 9 cases have been reported in the Japanese literature.

[A case of neuroendocrine carcinoma of the duodenal papilla].

A 75-year-old man with a complaint of right hypochondrial pain consulted our hospital, and was diagnosed as having acute cholecystitis. We performed percutaneous transhepatic gallbladder drainage (PTGBD), and the cholecystitis resolved. However, obstructive jaundice occurred 2 weeks later. Thus, we performed an in-depth investigation and detected duodenal papilla cancer (cT3N1M0, Stage III). Pancreatoduodenectomy was performed. As postoperative histological diagnosis yielded positive and strongly positive immunostaining for synaptophysin and Ki-67, respectively, we diagnosed the patient as having neuroendocrine carcinoma (NEC) of the duodenal papilla. Three months after surgery, computed tomography (CT) scan showed multiple liver metastases and lymph node metastasis. Chemotherapy with carboplatin and etoposide was administered, but severe neutropenia developed, and therefore, the chemotherapy was discontinued. Subsequently, we decided on a policy of best supportive care (BSC). The patient died 11 months after surgery. NEC of the duodenal papilla is reported to be a rare and rapidly progressing disease and is associated with a very poor prognosis. Herein, we report a case of a patient in whom NEC of the duodenal papilla was resected.

[A surgical case of peritoneal dissemination metastasis of bile duct carcinoma after pancreaticoduodenectomy].

The patient was a 50-year-old woman who had undergone pancreaticoduodenectomy for bile duct carcinoma in April 2010. In August 2011, abdominal computed tomography (CT) revealed a solitary tumor (30×17 mm in diameter) behind the anastomosis of gastrojejunostomy. Gastrointestinal endoscopy revealed gastrojejunal ulceration (biopsy: Group V adenocarcinoma). Positron emission tomography (PET)-CT revealed a solitary tumor without any recurrence. We diagnosed the patient as having solitary recurrence of peritoneal dissemination of bile duct carcinoma. In September 2011, we performed resection of the peritoneal dissemination. The patient was discharged from the hospital 12 days after the operation and had a good postoperative course. Histologically, the tumor was diagnosed as peritoneal dissemination of bile duct carcinoma. Subsequently, the patient received postoperative chemotherapy. The patient remains alive with recurrence of peritoneal dissemination 37 months after pancreaticoduodenectomy and 20 months after resection of the peritoneal dissemination.

[A case with a lower rectal gastrointestinal stromal tumor undergoing sphincter-preserving laparoscopic resection after neoadjuvant imatinib therapy].

A man in his 30s visited our hospital after a local doctor diagnosed him with a rectal submucosal tumor. Colonoscopy and fine needle biopsy revealed a lower rectal gastrointestinal tumor (GIST). Pelvic MRI examination revealed apparent tumor invasion of the left levator ani muscle. Curative abdominoperineal resection( APR) of the tumor was required. Our strategy involved the initiation of neoadjuvant imatinib therapy to facilitate subsequent sphincter-preserving resection. Neoadjuvant chemotherapy for 11 months reduced the tumor size and permitted the R0 laparoscopic sphincter-preserving resection. He was discharged without any postoperative complications. The pathological findings revealed semi-curative effects and pR0 resection. Thus, neoadjuvant chemotherapy for advanced rectal GIST was a useful strategy for this function- preserving operation.

Crohn's disease-related anal fistula cancer diagnosed by examination under anesthesia: a case report.

BACKGROUND: As the number of patients with inflammatory bowel disease (IBD) increases, the incidence of IBD-related colorectal cancer (CRC) is also on the rise. Crohn's disease (CD)-related CRC has been reported to have a poorer prognosis than sporadic CRC, and the early detection of CD-related CRC is difficult. Japanese patients with CD are reported to have a higher frequency of anorectal cancer than the Western population; however, methods for early diagnosis have not yet been established because of perianal pain during the examination. CASE PRESENTATION: We report a case of CD-related anal fistula cancer that was detected early by surveillance examination under anesthesia (EUA). The patient was a 37-year-old man, diagnosed with CD at the age of 15 years and started medical treatment. However, due to poor disease control, the intestinal tract remained highly inflamed and the patient continued to have over 10 bowel movements per day. He was referred to our hospital for surgical treatment after a colonoscopy (CS), which revealed multiple active ulcers and stenoses. Since three perianal seton drainage tubes had been placed around his anus since the age of 33 years, we decided to perform an EUA to rule out cancer coexistence in the anorectal region. After a random biopsy of the rectum by CS under general anesthesia, we resected and curetted multiple perianal fistulas as much as possible and reinserted the seton drainage tubes. Pathological examination of the fistula tract revealed adenocarcinoma in one tract, indicating the coexistence of anal fistula cancer. Based on the diagnosis of multiple intestinal stenoses and anal fistula cancer due to CD, we performed hand-assisted laparoscopic total colectomy, rectal amputation, extensive perineal resection, and reconstruction using a left rectus abdominis flap. CONCLUSION: In a long-term CD patient with anorectal lesions, we performed an EUA to diagnose the coexistence of anal fistula cancer at an early stage, and surgical resection was achieved. EUA is effective for the early detection and treatment of CD-related CRC and may contribute to an improved prognosis.

High Level Sacral Bone Resection for Locally Recurrent Rectal Cancer.

BACKGROUND/AIM: Locally recurrent rectal cancer (LRRC) involving the upper sacrum is generally considered a contraindication for curative surgery. In the surgical management of LRRC, sacrectomy is frequently performed to secure clear resection margins. Nonetheless, the indications for high sacrectomy remain controversial due to potential postoperative complications, questions about radicality, and the increased complexity of the operation. Furthermore, comprehensive studies addressing this issue are notably absent. This study aimed to assess the feasibility, safety, and surgical prognosis in high sacrectomy for LRRC. PATIENTS AND METHODS: All patients with LRRC who required concomitant sacrectomy, but did not include the inferior margin of the second sacral vertebra, between 2003 and 2014, were reviewed retrospectively. RESULTS: Eight patients with a median age of 59 years were included in this study. The proximal resection line for sacral bone resection was the central part of the S1 vertebra in one patient, lower edge of the S1 vertebra in six patients, and central part of the S2 vertebra in one patient. Negative margin resection was achieved in five out of the eight patients. The median operative time was 922 min, and the median operative blood loss volume was 6,370 ml. Major complications included pelvic abscess (n=5), ileus (n=1), and pulmonary vein embolism (n=1), none of which proved fatal during the postoperative period. Both the 5-year local re-recurrence-free survival rate and the 5-year distant metastasis-free survival rate were 50% (4/8). CONCLUSION: High sacrectomy is safe and feasible to achieve negative margins in patients with LRRC.

Surgery for Rectal Cancer With Mixed Reality of 3D Model During Operation: A Case Report.

Background/Aim: Recently, robotic surgery for rectal cancer has become a common minimally invasive surgery. In addition, the technology of augmented and mixed reality is applied in various living environments, including medicine. We successfully performed robotic surgery for rectal cancer with three-dimensional (3D) images as mixed reality (MR) using HoloLens2. Case Report: The patient was diagnosed with rectal cancer by colonoscopy and a positron-emission computed-tomography scan, and we performed robot-assisted anterior resection. The operator used HoloLens2 and performed the surgery while visualizing 3D images of pelvic anatomy with the location of the rectal cancer as hologram. The operation was performed completely and safely, and she was discharged 11 days after surgery with no postoperative complications. Conclusion: This case presents the usefulness of a MR system offering organ visualization as hologram during surgery.

KRAS inhibition activates an actionable CD24 'don't eat me' signal in pancreas cancer.

KRAS G12C inhibitor (G12Ci) has produced encouraging, albeit modest and transient, clinical benefit in pancreatic ductal adenocarcinoma (PDAC). Identifying and targeting resistance mechanisms to G12Ci treatment is therefore crucial. To better understand the tumor biology of the KRAS G12C allele and possible bypass mechanisms, we developed a novel autochthonous KRAS G12C -driven PDAC model. Compared to the classical KRAS G12D PDAC model, the G12C model exhibit slower tumor growth, yet similar histopathological and molecular features. Aligned with clinical experience, G12Ci treatment of KRAS G12C tumors produced modest impact despite stimulating a 'hot' tumor immune microenvironment. Immunoprofiling revealed that CD24, a 'do-not-eat-me' signal, is significantly upregulated on cancer cells upon G12Ci treatment. Blocking CD24 enhanced macrophage phagocytosis of cancer cells and significantly sensitized tumors to G12Ci treatment. Similar findings were observed in KRAS G12D -driven PDAC. Our study reveals common and distinct oncogenic KRAS allele-specific biology and identifies a clinically actionable adaptive mechanism that may improve the efficacy of oncogenic KRAS inhibitor therapy in PDAC. Significance: Lack of faithful preclinical models limits the exploration of resistance mechanisms to KRAS G12C inhibitor in PDAC. We generated an autochthonous KRAS G12C -driven PDAC model, which revealed allele-specific biology of the KRAS G12C during PDAC development. We identified CD24 as an actionable adaptive mechanisms in cancer cells induced upon KRAS G12C inhibition and blocking CD24 sensitizes PDAC to KRAS inhibitors in preclinical models.

[Laparoscopic reconstruction of jejunostomy catheter deviations in gastric and esophageal cancer patients who underwent jejunostomy].

Jejunostomy feeding is useful for maintaining nutrition in patients with gastric cancer and esophageal cancer. Special provisions must be made in cases of occlusion or dislocation of the jejunostomy catheter, and when the catheter is narrow and difficult to approach by endoscopy. Between 2007 and 2011, we encountered 69 cases of jejunostomy: 40 performed for gastric cancer and 29 for esophageal cancer. Catheter occlusion was seen in 7 cases and catheter dislocation in 9. Of these 16 cases, 14 could be recovered using interventional radiology (IVR), and the remaining 2 could not be because of fistel closure.

[Total pancreatectomy for pancreatic head cancer accompanied with multiple lesions].

Our patient was a 67-year-old man, with a chief complaint of brown urine. He subsequently underwent medical examination in June. Because the results of his blood examination revealed liver dysfunction, he was admitted to our hospital for further careful examination. An abdominal computed tomography(CT) scan showed the presence of a pancreas tumor, with a diameter of 2 cm, at the pancreas head, as well as common biliary duct dilatation and main pancreatic duct dilation from the head to the tail of the pancreas. The patient was diagnosed with pancreatic cancer[cT3( CH+, DU+), cN0, cM0, cStage III], with obstructive jaundice. After biliary drainage, we performed laparotomy in August. During the operation, other than the tumor on the pancreas head, identified at the preoperative diagnosis, we found 2 white nodules on the pancreas surface. One nodule was located at the body of the pancreas and the other, at its tail. On intraoperative pathological examination of the nodules, they were found to be invasive ductal carcinomas. On the basis of these findings, we suspected multiple cancers or overall pancreatic cancer; therefore, we performed total pancreatectomy, not pancreaticoduodenectomy (PD). We choose pancreatectomy over PD because it was impossible to confirm the cancerous area. Pathological examination of the resected specimen did not reveal any malignant lesion. Thus, if we had not performed pancreatectomy, assuming that the pancreas body or tail had no cancer lesion, based on the pathological examination result, the cancer would have persisted. Further, careful examination involving inspection and palpation is considered to be essential before resection of the pancreas tumor.

[A case of invasive ductal carcinoma of the pancreas originating from an intraductal papillary mucinous tumor that was initially misdiagnosed as a mucinous cystic tumor].

A 57-year-old woman was discovered to have a cystic tumor, 8 cm in diameter, at the pancreas tail, during routine screening with ultrasonography. The patient did not complain of tenderness, and no abdominal mass was palpable at physical examination. Enhanced computed tomography(CT) revealed that the tumor had mural nodules in the cyst wall, and we suspected it to be a malignant tumor that had occurred in the mucinous cystic neoplasm(MCN). Therefore, surgical resection was attempted, upon which the tumor was found to be hard and the surrounding tissue adhered widely to the stomach. We separated it carefully from the stomach and then performed a distal pancreatectomy. The cut surface revealed that the posterior wall of the cystic tumor was partly thickened, and microscopic examination revealed it to be invasive ductal carcinoma. No ovarian-like stroma was involved and some degree of dysplasia(PanIN 1-3) was found in the neighboring tissues. Therefore, we re-diagnosed it to be invasive ductal carcinoma of the pancreas derived from intraductal papillary mucinous tumor(IPMT), not from MCN. The patient received adjuvant chemotherapy, although 5 months later multiple lung metastases had appeared. The international consensus guidelines for management of IPMN and MCN of the pancreas suggest that they can usually be distinguished preoperatively, if there is a complete understanding of their clinical and imaging features. However, we sometimes find it difficult to distinguish the 2, because some IPMN or MCN cases have shared preoperative features. Herein, we report the case of invasive ductal carcinoma of the pancreas derived from IPMT that was originally misdiagnosed as a MCN.