Undifferentiated carcinomas with osteoclastic giant cells of the pancreas (OGC) are rare tumors. The current impression in the literature is that they are highly aggressive tumors similar in prognosis to ductal adenocarcinomas. In this study, the clinicopathologic characteristics of 38 resected OGCs were investigated and contrasted with 725 resected pancreatic ductal adenocarcinomas without osteoclastic cells (PDCs). The frequency among systematically reviewed pancreatic cancers was 1.4%. OGCs showed a slight female predominance (62.9%, vs. 51.4% in PDCs). The mean age was 57.9 years (vs. 65.0). The mean size of invasive cancer was 5.3 cm (vs. 3.2). They were characterized by nodular, pushing-border growth, and 8 arose in tumoral intraepithelial neoplasms (4 in mucinous cystic neoplasms, 4 in intraductal papillary mucinous neoplasms type lesions), and 23 (61%) also showed prominent intraductal/intracystic growth. Twenty-nine (76%) had an invasive ductal/tubular adenocarcinoma component. Osteoid was seen in 12. Despite their larger size, perineural invasion and nodal metastasis were uncommon (31.6% and 22.6%, vs. 85.5% and 64.0%, respectively). Immunohistochemistry performed on 24 cases revealed that osteoclastic cells expressed the histiocytic marker CD68, and background spindle cells and pleomorphic/giant carcinoma cells often showed p53 and often lacked cytokeratin. Survival of OGCs was significantly better than that of PDCs (5 yr, 59.1% vs. 15.7%, respectively, P=0.0009). In conclusion, pancreatic OGCs present with larger tumor size and in slightly younger patients than PDC, 21% arise in mucinous cystic neoplasms/intraductal papillary mucinous neoplasms, and 61% show intraductal/intracystic polypoid growth. OGCs have a significantly better prognosis than is currently believed in the literature.

Objective:To determine the associations of pancreatobiliary maljunction (PBM) in the West.Background:PBM (anomalous union of common bile duct and pancreatic duct) is mostly regarded as an Asian-only disorder, with 200X risk of gallbladder cancer (GBc), attributed to reflux of pancreatic enzymes. Methods: Radiologic images of 840 patients in the US who underwent pancreatobiliary resections were reviewed for PBM and contrasted with 171 GBC cases from Japan.Results:Eight % of the US GBCs (24/300) had PBM (similar to Japan; 15/ 171, 8.8%), in addition to 1/42 bile duct carcinomas and 5/33 choledochal cysts. None of the 30 PBM cases from the US had been diagnosed as PBM in the original work-up. PBM was not found in other pancreatobiliary disorders. Clinicopathologic features of the 39 PBM-associated GBCs (US:24, Japan:15) were similar; however, comparison with non-PBM GBCs revealed that they occurred predominantly in females (F/M = 3); at younger (<50-year-old) age (21% vs 6.5% in non-PBM GBCs; P = 0.01); were uncommonly associated with gallstones (14% vs 58%; P < 0.001); had higher rate of tumor-infiltrating lymphocytes (69% vs 44%; P = 0.04); arose more often through adenoma-carcinoma sequence (31% vs 12%; P = 0.02); and had a higher proportion of nonconventional carcinomas (21% vs 7%; P = 0.03). Conclusions: PBM accounts for 8% of GBCs also in the West but is typically undiagnosed. PBM-GBCs tend to manifest in younger age and often through adenoma-carcinoma sequence, leading to unusual carcinoma types. If PBM is encountered, cholecystectomy and surveillance of bile ducts is warranted. PBM-associated GBCs offer an invaluable model for variant anatomy-induced chemical (reflux-related) carcinogenesis.

Background: The path of the biliopancreatic limb for reconstruction of the pancreatic anastomosis during pancreatoduodenectomy for pancreatic ductal adenocarcinoma can be trans-mesocolon or through the ligament of Treitz. Even after curative intent pancreatoduodenectomy, incidence of recurrence in the surgical bed remains high and may lead to obstruction of the biliopancreatic limb. However, the association between path of jejunal limb and incidence of biliopancreatic limb obstruction has not been studied. Primary aim was to determine whether path of reconstruction predisposes to biliopancreatic limb obstruction in the setting of local recurrence. Methods: Patients who underwent pancreatoduodenectomy for pancreatic ductal adenocarcinoma (2008–2018) from a single institution were identified. As disease recurrence is the predominant cause of biliopancreatic limb obstruction, analysis was limited to patients with known recurrence at date of last follow-up. Given a known median time to recurrence of 8 to 10 months after resection for pancreatic ductal adenocarcinoma, analysis was further limited to patients with at least 8 months of follow-up. Primary outcome was incidence of biliopancreatic limb obstruction. Results: Among the 517 patients identified, 182 were included. Median age was 65 years; 51% were male. Median follow-up was 22 months. Path of reconstruction was trans-mesocolon in 35% (n = 64) and through ligament of Treitz in 65% (n = 118). There was no difference between the two groups in clinicopathologic factors including age, tumor differentiation, grade, T-stage, N-stage, LVI, or PNI (all p > 0.05). Importantly, there was no difference in retroperitoneal margin positivity between groups (trans-mesocolon 8% vs ligament of Treitz 10%, p = 0.79). Both groups had similar post-operative outcomes including median length-of-stay (trans-mesocolon 6 days vs ligament of Treitz 6 days, p = 0.89) and median follow-up (trans-mesocolon 21 months vs ligament of Treitz 23 months, p = 0.68). Biliopancreatic limb obstruction was detected in 8% (n = 14) of which 14% (n = 2) were in the trans-mesocolon group and 86% (n = 12) were in the ligament of the Treitz group. Therefore, incidence of biliopancreatic limb obstruction was 3.1% in the trans-mesocolon group and 10.4% in the ligament of the Treitz group resulting in an absolute risk increase of 7.3%, risk ratio of 3.4, and relative risk increase of 2.3. There was no difference in median time to biliopancreatic limb obstruction between the groups (17.6 months vs 18.5 months, p = 1.0). Biliopancreatic limb obstruction was caused by locally recurrent pancreatic ductal adenocarcinoma in 93% (n = 13) and kinking of the duodenojejunal anastomosis in 7% (n = 1). Intervention was performed in 71% (n = 10) and included surgical bypass in 29% (n = 4), percutaneous drain in 21% (n = 3), and endoscopic/surgical decompression in 21% (n = 3). Conclusion: Biliopancreatic limb obstruction is a known complication after pancreatoduodenectomy for pancreatic ductal adenocarcinoma due to local recurrence in the surgical bed. This study shows that path of jejunal limb through the ligament of Treitz may be associated with a higher incidence of biliopancreatic limb obstruction compared with trans-mesocolon as the position of the biliopancreatic limb in the surgical bed may be more predisposed to obstruction after local recurrence. Larger studies are needed; however, given this potential risk of subsequent obstruction, these data suggest that the reconstruction paths may not be equivalent when performing pancreatoduodenectomy for pancreatic ductal adenocarcinoma.

Background: Both minimally invasive surgery (MIS) and open approaches for distal pancreatectomy are acceptable. MIS options include total laparoscopic/robotic (TLR) and hand-assist laparoscopy (HAL). When considering safety profile and specimen quality, the optimal approach is unknown. Methods: Patients who underwent distal pancreatectomy from 2010-2018 at two major academic institutions were included. Converted procedures were categorized into final approach. Ninety-day perioperative/pathologic outcomes of MIS and open were compared. Subset analyses between TLR vs HAL and HAL vs open were performed. Intent-to-treat analysis was performed. Results: Among 1006 patients, resection was performed by MIS in 35% (n = 352), open in 65% (n = 654). MIS had similar patient comorbidity profile as open but had increased operative time (183 vs 162 min; p < 0.01), lower estimated-blood-loss (EBL; 131 vs 341 mL; p < 0.01), fewer intraoperative blood transfusions (1.4 vs 5%; p < 0.01), shorter LOS (5.2 vs 7.2 days; p < 0.01). Tumor size was smaller (3.2 vs 4.4 cm; p < 0.01) with lower lymph node (LN) yield (14 vs 16; p < 0.01). When comparing HAL (n = 109) to TLR (n = 243), despite increased prior abdominal operations (60 vs 43%; p = 0.008), HAL had shorter operative time (167 vs 191 min; p < 0.01), similar length-of-stay (LOS; 5.4 vs 5.1 days; p = 0.27), and readmission rate (15 vs 13%; p = 0.47). When comparing HAL to open, the advantages of TLR approach persisted including lower EBL (171 vs 342 mL; p < 0.01), and shorter LOS (5.4 vs 7.2 days; p < 0.01). Although HAL had smaller tumors, it had a similar LN yield (16 vs 16; p = 0.80), and higher R0-rate (97 vs 83%; p < 0.01). Conclusion: Hand-assist laparoscopy is safe and feasible for distal pancreatectomy as operative time, complication profile, lymph node yield, and R0-rates are similar to open procedures, while maintaining the associated the advantages of a total laparoscopic/robotic approach with reduced blood loss and shorter length-of-stay.

Pancreaticobiliary maljunction (PBM) is the anomalous union of the main pancreatic duct and common bile duct outside the Oddi-sphincter, allowing the reflux of pancreatic juice to the gallbladder. There is only limited awareness and understanding of the pathologic correlates of this condition, mostly from Japan; this entity is largely unrecognized in the West. In this study, 76 gallbladders from patients with PBM (64 from Japan; 12 from the United States) were analyzed and contrasted with 66 from non-PBM patients. These were predominantly females (54 vs. 22), mean age, 53 (range: 14 to 81). Cholelithiasis was uncommon (16% vs. 80% in non-PBM, P<0.01) whereas cholesterolosis was more common (49% vs. 29%, P=0.02) suggesting an altered chemical milieu. There was a distinctive diffuse mucosal hyperplasia (82% vs. 42%, P<0.01) with markedly elongated folds (mean: 1.1 vs. 0.7 mm, P<0.01) composed of compact villoglandular proliferation, often showing broad-based pushing into muscle, accompanied by prominent and more complex Rokitansky-Aschoff sinus formation (2.0 vs. 1.0/cm, P<0.01) at the base. At the tips, this villiform hyperplasia displayed frequent horizontal bridging of the folds (68% vs. 47%, P=0.01), bulbous dilatation (52% vs. 21%, P<0.01) as well as deposition of a peculiar amyloid-like hyaline material (56% vs. 15%, P<0.01). Despite paucity of inflammation and gallstones, findings attributed to mucosal injury were common including: pyloric gland metaplasia (70% vs. 48%, P=0.01) and intestinal metaplasia (24% vs. 6%, P<0.01). Invasive gallbladder carcinoma was present in 22 (29%) of the cases with 6 of these (27%) arising in association with intracholecystic papillary tubular neoplasm. Five cases had bile duct carcinoma at the time of cholecystectomy and 1 developed it 4 years after. In conclusion, gallbladders with patients with PBM display a distinctive pattern of mucosal hyperplasia with distinguishing features, which in constellation render it a microscopically diagnosable specific entity. We propose to refer to this entity as "reflux-associated cholecystopathy." Recognition of the pathologic characteristics of this entity is important so that investigation for, as well as treatment and prevention of, PBM-associated complications (biliary tract cancers and pancreatitis) can be instituted. This group also offers a distinct model of carcinogenesis (chemical rather than inflammatory) in the gallbladder for cancer researchers to scrutinize.

There is no systematic histopathologic analysis of non-neoplastic polyps in the gallbladder. In this study, in addition to a computer search for cases designated as "polyp," a systematic review of 2533 consecutive routinely sampled archival and 203 totally submitted prospective cholecystectomies were analyzed for >2 mm polyps (cut-off was based on radiologic sensitivity). A total of 447 non-neoplastic polyps were identified. The frequency was 3% in archival cases and 5% in totally submitted cases. Only 21 (5%) were ≥1 cm. The average age was 52 years, and the female to male ratio was 3.1. Two distinct categories were delineated: (1) injury-related polyps (n=273): (a) Fibro(myo)glandular polyps (n=214) were small (mean=0.4 cm), broad-based, often multiple (45%), almost always (98%) gallstone-associated, and were composed of a mixture of (myo)fibroblastic tissue/lobular glandular units with chronic cholecystitis. Dysplasia seen in 9% seemed to be secondary involvement. (b) Metaplastic pyloric glands forming polypoid collections (n=42). (c) Inflammatory-type polyps associated with acute/subacute injury (11 granulation tissue, 3 xanthogranulomatous, 3 lymphoid). (2) Cholesterol polyps (n=174) occurred in uninjured gallbladders, revealing a very thin stalk, edematous cores devoid of glands but with cholesterol-laden macrophages in 85%, and cholesterolosis in the uninvolved mucosa in 60%. Focal low-grade dysplasia was seen in 3%, always confined to the polyp, unaccompanied by carcinoma. In conclusion, non-neoplastic polyps are seen in 3% of cholecystectomies and are often small. Injury-related fibromyoglandular polyps are the most common. Cholesterol polyps have distinctive cauliflower architecture, often in a background of uninjured gallbladders with cholesterolosis and may lack the cholesterol-laden macrophages in the polyp itself. Although dysplastic changes can involve non-neoplastic polyps, they do not seem to be the cause of invasive carcinoma by themselves.

Background: Pancreatoduodenectomy (PD) for duodenal adenoma (DA) resection may be associated with excessive surgical risk for patients with potentially benign lesions, given the absence of pancreatic duct obstruction. We examined factors associated with final malignant pathology and evaluated the postoperative course of patients with DA versus pancreatic ductal adenocarcinoma (PDAC). Methods: We retrospectively analyzed patients with DA who underwent PD from 2008 to 2018 and assessed the accuracy rate of preoperative biopsy and factors associated with final malignant pathology. Complications for DA patients were compared with those of matched PDAC patients. Results: Forty-five consecutive patients who underwent PD for DA were identified, and the preoperative biopsy false negative rate was 29. Factors associated with final malignant pathology included age over 70 years, preoperative biliary obstruction, and common bile duct diameter > 8 mm (p < 0.05). Compared with patients with PDAC (n = 302), DA patients experienced more major complications (31% vs. 15%, p < 0.01), more grade C postoperative pancreatic fistulas (9% vs. 1%, p < 0.01), and greater mortality (7% vs. 2%, p < 0.05). Propensity score matched patients with DA had more major complications following PD (32% vs. 12%, p < 0.05). Conclusions: Preoperative biopsy of duodenal adenomas is associated with a high false-negative rate for malignancy, and PD for DA is associated with higher complication rates than PD for PDAC. These results aid discussion among patients and surgeons who are considering observation versus PD for DA, especially in younger patients without biliary obstruction, who are less likely to harbor malignancy.

Pancreatic ductal adenocarcinoma (PDAC) has a prominent fibrotic stroma, which is a result of interactions between tumor, immune and pancreatic stellate cells (PSC), or cancer-associated fibroblasts (CAF). Targeting inflammatory pathways present within the stroma may improve access of effector immune cells to PDAC and response to immunotherapy. Heat shock protein-90 (Hsp90) is a chaperone protein and a versatile target in pancreatic cancer. Hsp90 regulates a diverse array of cellular processes of relevance to both the tumor and the immune system. However, to date the role of Hsp90 in PSC/CAF has not been explored in detail. We hypothesized that Hsp90 inhibition would limit inflammatory signals, thereby reprogramming the PDAC tumor microenvironment to enhance sensitivity to PD-1 blockade. Treatment of immortalized and primary patient PSC/CAF with the Hsp90 inhibitor XL888 decreased IL6, a key cytokine that orchestrates immune changes in PDAC at the transcript and protein level in vitro. XL888 directly limited PSC/CAF growth and reduced Jak/STAT and MAPK signaling intermediates and alpha-SMA expression as determined via immunoblot. Combined therapy with XL888 and anti–PD-1 was efficacious in C57BL/6 mice bearing syngeneic subcutaneous (Panc02) or orthotopic (KPC-Luc) tumors. Tumors from mice treated with both XL888 and anti–PD-1 had a significantly increased CD8þ and CD4þ T-cell infiltrate and a unique transcriptional profile characterized by upregulation of genes associated with immune response and chemotaxis. These data demonstrate that Hsp90 inhibition directly affects PSC/CAF in vitro and enhances the efficacy of anti–PD-1 blockade in vivo.

Introduction: Over half of all gallbladder carcinoma (GBC) is discovered incidentally after cholecystectomy for benign disease. There are scant data comparing presentation and outcome for patients with incidental versus suspected GBC. The goal of this study is to determine the clinical differences between these two entities. Study Design: Patients with GBC were identified retrospectively from records at academic healthcare institutions in Temuco, Chile; Atlanta, GA; and Rochester, MN between 1984 and 2008. Overall survival was compared for patients with and without preoperative suspicion using Kaplan–Meier curves and a multivariate Cox proportional hazards model. Results: Of 571 patients, 128 (22.4 %) had preoperative suspicion of malignancy, and 443 (77.6 %) were discovered incidentally. Incidental tumors were of lower stage, better differentiated, and with lower rates of metastases. Median survival for incidentally discovered GBC was 32.3 versus 5.8 months for suspected GBC (p<0.0001). In a Cox proportional hazards model controlling for operation extent, T stage, differentiation, and other factors, preoperative suspicion remains a strong risk factor (odds ratio, 2.0; confidence interval, 1.5–2.9; p<0.0001). Conclusions: Tumor characteristics differed significantly between patients with incidentally discovered versus preoperatively suspected GBC. Incidental GBC has a significantly better median survival.

Background: Numerous recent reports describe the performance of laparoscopic procedures through a single incision. Although the feasibility of this approach for a variety of procedures is currently being established, little data are available regarding safety. Case Report: A 65-year-old female patient who was transferred from an outside institution had undergone a single incision laparoscopic cholecystectomy that resulted in biliary tract and vascular injuries. Methods: The patient was transferred with a known bile duct injury on the first postoperative day following single incision laparoscopic cholecystectomy. Review of her magnetic resonance imaging and percutaneous transhepatic cholangiogram studies showed a Bismuth type 3 bile duct injury. Hepatic angiogram demonstrated an occlusion of the right hepatic artery with collateralization from the left hepatic artery. She was initially managed conservatively with a right-sided external biliary drain, followed 6 weeks later by a Hepp-Couinaud procedure to reconstruct the biliary tract. Conclusion: As new techniques evolve, it is imperative that safety, or potential side effects, or both safety and side effects, be monitored, because no learning curve is established for these new techniques. In these initial stages, surgeons should have a low threshold to add additional ports when necessary to ensure that procedures are completed safely.