Pancreas/Biliary, in full.

Confirm chronic pancreatitis on CROSS-SECTIONAL IMAGING, CT for late calcific disease, MRI/MRCP (with secretin where available) for earlier ductal and parenchymal change, EUS an acceptable alternative; per ACG 2020, "Diagnosis is made usually on cross-sectional imaging, with modalities such as endoscopic ultrasonography and pancreatic function tests playing a secondary role". Fecal elastase does NOT confirm chronic pancreatitis: it is a test of exocrine FUNCTION and is the appropriate initial test for the exocrine pancreatic insufficiency (EPI) that chronic pancreatitis causes, a consequence of the disease, not the diagnosis of it. A normal fecal elastase does not exclude chronic pancreatitis and a low one does not establish it. Per AGA 2023, fecal elastase must be run on a semi-solid or solid stool specimen; below 100 mcg/g is good evidence of EPI and 100-200 mcg/g is indeterminate (below 200 mcg/g is the cutoff commonly used to screen). Then manage with smoking and alcohol cessation, PERT for exocrine insufficiency titrated to symptoms, fat-soluble vitamin and bone surveillance, and individualized type 3c diabetes control, considering insulin early in patients with marked hyperglycemia or symptoms of insulin deficiency. Treat pain with a stepwise ladder from scheduled acetaminophen and neuromodulators to EUS-guided celiac plexus block and endoscopic/surgical intervention, referring early for surgery per ESCAPE 2020 in candidates with main pancreatic duct obstruction. Screen for PDAC per lifetime risk and pursue etiologic workup via TIGAR-O v2, including genetic testing and autoimmune pancreatitis evaluation.

Evaluate suspected pancreatic adenocarcinoma with a dedicated pancreatic-protocol (multiphasic, contrast-enhanced) CT of the abdomen as the preferred imaging for diagnosis and staging (MRI/MRCP is an acceptable alternative); PET/CT may be added after, never as a substitute for, protocol CT/MRI in higher-risk situations. Obtain tissue confirmation, preferably by EUS-guided FNA/FNB with core biopsy where feasible; biopsy is generally required before neoadjuvant or palliative therapy, whereas patients with clearly resectable disease may proceed to surgery without preoperative biopsy. Measure baseline CA 19-9 (interpret after biliary decompression / with normal bilirubin; it can be falsely low in Lewis-antigen-negative patients and falsely elevated with cholestasis). Offer GERMLINE testing for inherited susceptibility to EVERY patient with confirmed pancreatic adenocarcinoma regardless of family history, using a comprehensive multi-gene panel; separately, for patients with locally advanced or metastatic disease who are candidates for anti-cancer therapy, obtain TUMOR/SOMATIC molecular profiling (broad NGS; RNA-based assays improve fusion detection; cell-free/liquid biopsy if tissue is insufficient). Assign resectability, resectable, borderline resectable, locally advanced (unresectable), or metastatic, by multidisciplinary review, ideally at a high-volume center. RESECTABLE disease: upfront resection (pancreaticoduodenectomy for head/uncinate; distal pancreatectomy ± splenectomy for body/tail) followed by adjuvant therapy, or neoadjuvant therapy in selected high-risk patients; preferred adjuvant regimen is modified FOLFIRINOX in patients able to tolerate it, ideally begun within 12 weeks of surgery, for a total of ~6 months of perioperative systemic therapy. BORDERLINE RESECTABLE and LOCALLY ADVANCED disease: neoadjuvant systemic therapy, with or without subsequent chemoradiation/RT, then restaging and reassessment for resection. METASTATIC disease by performance status: good PS (ECOG 0-1, adequate organ function), first-line FOLFIRINOX/modified FOLFIRINOX, NALIRIFOX, or gemcitabine + nab-paclitaxel, with clinical trial preferred; after ~4-6 months without progression, transition to a maintenance strategy (including olaparib for germline BRCA1/2 carriers who have NOT progressed on first-line platinum-based therapy), a clinical trial, or a treatment break; intermediate PS (ECOG 2), clinical trial preferred, otherwise less-intensive first-line therapy (preferred gemcitabine + nab-paclitaxel [category 1], or single-agent gemcitabine or capecitabine, or FOLFOX/FOLFIRI/CapeOx), since the intensive triplets (FOLFIRINOX/modified FOLFIRINOX and NALIRIFOX) are limited to ECOG 0-1 and are generally not appropriate at ECOG 2, with the same maintenance-versus-progression reassessment applied after ~4-6 months without progression; poor PS (ECOG 3-4), palliative/best supportive care, with single-agent chemotherapy or a biomarker-directed agent only if clinically appropriate. Treat by molecular target wherever an actionable alteration is present, across lines: pembrolizumab (or dostarlimab) for MSI-H/dMMR and pembrolizumab for TMB-H, olaparib for germline BRCA1/2 (maintenance after platinum), larotrectinib/entrectinib for NTRK fusions, selpercatinib for RET fusions, dabrafenib + trametinib for BRAF V600E, erdafitinib for FGFR2 alterations, fam-trastuzumab deruxtecan for HER2-positive disease, zenocutuzumab for NRG1 fusion-positive disease, and (in recent NCCN versions) KRAS G12C inhibitors (adagrasib/sotorasib), several of these after prior systemic therapy. Integrate supportive care throughout: relieve obstructive jaundice with an endoscopic self-expanding metal stent in non-operative or neoadjuvant pathways, but do NOT perform routine preoperative biliary drainage before planned upfront resection; treat exocrine insufficiency with pancreatic enzyme replacement titrated to symptoms (common starting dose ~40,000-50,000 units of lipase with main meals, roughly half with snacks, increased as needed); manage refractory pain with celiac plexus neurolysis or palliative RT; relieve gastric outlet obstruction with surgical or EUS-guided gastrojejunostomy (or enteral stenting); and provide VTE prophylaxis, nutritional support, and early palliative care.

Diagnose acute pancreatitis (AP) by the Atlanta criteria (2 of 3: characteristic epigastric/LUQ pain, lipase or amylase >3x ULN [lipase preferred for specificity/duration], or characteristic imaging). ACG 2024 stratifies severity risk using SIRS on admission plus bedside risk factors, rising/elevated BUN, rising/elevated hematocrit (>44), obesity (BMI>30), extrapancreatic fluid collections/pleural effusion/infiltrates, altered mental status, and older age/comorbidities, rather than mandating a formal BISAP or APACHE II composite score. Give moderately aggressive lactated Ringer's, most important in the first 6-12 hours, reassessing volume status/BUN/HCT at 6 hours (further aggressive hydration has little added benefit after 24-48h). Start oral low-fat solid food within 24-48h as tolerated in mild disease; if enteral feeding is needed for moderately severe/severe disease, prefer nasogastric over nasojejunal with small-peptide/medium-chain-triglyceride formula and continuous (not bolus/cyclic) feeding; avoid parenteral nutrition if possible. Do not give prophylactic antibiotics, even in severe disease or sterile necrosis; reserve antibiotics for suspected infected necrosis (typically arising 10-14 days in), and choose agents that penetrate pancreatic necrosis while together covering both gut-derived gram-negative enterics and anaerobes, a carbapenem supplies this as monotherapy, whereas a fluoroquinolone or a third-or-higher-generation cephalosporin must be combined with metronidazole; metronidazole alone (anaerobic cover only), or a cephalosporin or a quinolone alone, does not adequately treat infected necrosis. Perform cholecystectomy preferably before discharge for mild acute biliary pancreatitis, and after a second unexplained AP episode even without identified gallstones; reserve ERCP within 24h for AP complicated by cholangitis, with rectal indomethacin +/- pancreatic duct stent and periprocedural hydration to reduce post-ERCP pancreatitis risk. Check triglycerides when gallstones/alcohol are absent (>1000 mg/dL supports a hypertriglyceridemia etiology). For stable pancreatic necrosis, defer surgical, radiological, or endoscopic intervention 4-6 weeks to allow walling-off (step-up approach).

Diagnose acute pancreatitis (AP) by the Atlanta criteria (2 of 3: characteristic epigastric/LUQ pain, lipase or amylase >3x ULN [lipase preferred for specificity/duration], or characteristic imaging). ACG 2024 stratifies severity risk using SIRS on admission plus bedside risk factors, rising/elevated BUN, rising/elevated hematocrit (>44), obesity (BMI>30), extrapancreatic fluid collections/pleural effusion/infiltrates, altered mental status, and older age/comorbidities, rather than mandating a formal BISAP or APACHE II composite score. Give moderately aggressive lactated Ringer's, most important in the first 6-12 hours, reassessing volume status/BUN/HCT at 6 hours (further aggressive hydration has little added benefit after 24-48h). Start oral low-fat solid food within 24-48h as tolerated in mild disease; if enteral feeding is needed for moderately severe/severe disease, prefer nasogastric over nasojejunal with small-peptide/medium-chain-triglyceride formula and continuous (not bolus/cyclic) feeding; avoid parenteral nutrition if possible. Do not give prophylactic antibiotics, even in severe disease or sterile necrosis; reserve antibiotics for suspected infected necrosis (typically arising 10-14 days in), and choose agents that penetrate pancreatic necrosis while together covering both gut-derived gram-negative enterics and anaerobes, a carbapenem supplies this as monotherapy, whereas a fluoroquinolone or a third-or-higher-generation cephalosporin must be combined with metronidazole; metronidazole alone (anaerobic cover only), or a cephalosporin or a quinolone alone, does not adequately treat infected necrosis. Perform cholecystectomy preferably before discharge for mild acute biliary pancreatitis, and after a second unexplained AP episode even without identified gallstones; reserve ERCP within 24h for AP complicated by cholangitis, with rectal indomethacin +/- pancreatic duct stent and periprocedural hydration to reduce post-ERCP pancreatitis risk. Check triglycerides when gallstones/alcohol are absent (>1000 mg/dL supports a hypertriglyceridemia etiology). For stable pancreatic necrosis, defer surgical, radiological, or endoscopic intervention 4-6 weeks to allow walling-off (step-up approach).

Kyoto 2024 (IAP) is still the core algorithm for IPMN, and nothing in it has changed. MD-, mixed- and BD-IPMN all go through one HRS/WF algorithm. MDCT, MRI/MRCP and EUS are treated as equivalent for diagnosis, with tumor markers and HbA1c added. Since 2024, EUS imaging and EUS-FNA cytology count toward HRS/WF when EUS is done. High-risk stigmata are: obstructive jaundice with a head cyst; an enhancing mural nodule >=5 mm or a solid component; MPD >=10 mm; or suspicious/positive cytology. Worrisome features are: pancreatitis; CA19-9 >37 U/mL; new-onset or worsening diabetes within 1 year; cyst >=30 mm; enhancing mural nodule <5 mm; thickened or enhancing cyst wall; MPD 5-9 mm; abrupt change in duct caliber with distal atrophy; lymphadenopathy; or growth >=2.5 mm/year. HRS should prompt consideration of resection, weighed against fitness and life expectancy; it does not mean automatic surgery. WF should prompt EUS and multidisciplinary review. EUS-FNA is used only when its result would change management. Surveillance of non-resected BD-IPMN depends on size: <20 mm at 6 months, then every 18 months; 20 to <30 mm every 6 months twice, then every 12 months; >=30 mm every 6 months. Under Kyoto, surveillance may stop for cysts <20 mm with no change and no WF after 5 years, and should stop if the patient is unfit for surgery or life expectancy is <10 years. Continued surveillance remains an option because the risk of a separate pancreatic cancer keeps accumulating. NEW in 2026: an AGA Clinical Practice Update (Das, Serper, Vege; expert opinion, not formally graded) adds stopping rules by age and comorbidity for any pancreatic cystic lesion. (1) At any age, patients with significant comorbidity (age-adjusted Charlson index >=3-5) and an incidental, especially low-risk, cyst should be counseled against routine surveillance. (2) Over 65, cysts <=15 mm stable for 5 years with no WF/HRS should be considered for stopping after shared decision-making. 'Stable' means growth under 3 mm/year and under 6 mm over 2 years. (3) Over 75, cysts <30 mm stable for 5 years with no WF/HRS call for a discussion of whether surveillance is worth continuing, and it may stop if the patient accepts the small residual risk. (4) If comorbidity develops that rules out surgery, stopping should be discussed, even when WF/HRS were found earlier, provided there is no evidence of HGD or cancer. (5) After resection with no HGD or cancer, the remnant follows the same rules, counting surveillance time before surgery, and stopping is discussed after 5 years of stability. (6) After resection with HGD, MRI/MRCP every 6 months for 2 years and then yearly while the patient can still have a completion pancreatectomy. If invasive cancer was found, the remnant follows oncology guidelines. In both cases, stopping is discussed with oncology after 5 years of remnant stability with no WF/HRS. The resect-all-MCNs rule and the familial/germline (CAPS) screening pathway come from other guidelines, not from either of these documents.

Evaluate suspected pancreatic adenocarcinoma with a dedicated pancreatic-protocol (multiphasic, contrast-enhanced) CT of the abdomen as the preferred imaging for diagnosis and staging (MRI/MRCP is an acceptable alternative); PET/CT may be added after, never as a substitute for, protocol CT/MRI in higher-risk situations. Obtain tissue confirmation, preferably by EUS-guided FNA/FNB with core biopsy where feasible; biopsy is generally required before neoadjuvant or palliative therapy, whereas patients with clearly resectable disease may proceed to surgery without preoperative biopsy. Measure baseline CA 19-9 (interpret after biliary decompression / with normal bilirubin; it can be falsely low in Lewis-antigen-negative patients and falsely elevated with cholestasis). Offer GERMLINE testing for inherited susceptibility to EVERY patient with confirmed pancreatic adenocarcinoma regardless of family history, using a comprehensive multi-gene panel; separately, for patients with locally advanced or metastatic disease who are candidates for anti-cancer therapy, obtain TUMOR/SOMATIC molecular profiling (broad NGS; RNA-based assays improve fusion detection; cell-free/liquid biopsy if tissue is insufficient). Assign resectability, resectable, borderline resectable, locally advanced (unresectable), or metastatic, by multidisciplinary review, ideally at a high-volume center. RESECTABLE disease: upfront resection (pancreaticoduodenectomy for head/uncinate; distal pancreatectomy ± splenectomy for body/tail) followed by adjuvant therapy, or neoadjuvant therapy in selected high-risk patients; preferred adjuvant regimen is modified FOLFIRINOX in patients able to tolerate it, ideally begun within 12 weeks of surgery, for a total of ~6 months of perioperative systemic therapy. BORDERLINE RESECTABLE and LOCALLY ADVANCED disease: neoadjuvant systemic therapy, with or without subsequent chemoradiation/RT, then restaging and reassessment for resection. METASTATIC disease by performance status: good PS (ECOG 0-1, adequate organ function), first-line FOLFIRINOX/modified FOLFIRINOX, NALIRIFOX, or gemcitabine + nab-paclitaxel, with clinical trial preferred; after ~4-6 months without progression, transition to a maintenance strategy (including olaparib for germline BRCA1/2 carriers who have NOT progressed on first-line platinum-based therapy), a clinical trial, or a treatment break; intermediate PS (ECOG 2), clinical trial preferred, otherwise less-intensive first-line therapy (preferred gemcitabine + nab-paclitaxel [category 1], or single-agent gemcitabine or capecitabine, or FOLFOX/FOLFIRI/CapeOx), since the intensive triplets (FOLFIRINOX/modified FOLFIRINOX and NALIRIFOX) are limited to ECOG 0-1 and are generally not appropriate at ECOG 2, with the same maintenance-versus-progression reassessment applied after ~4-6 months without progression; poor PS (ECOG 3-4), palliative/best supportive care, with single-agent chemotherapy or a biomarker-directed agent only if clinically appropriate. Treat by molecular target wherever an actionable alteration is present, across lines: pembrolizumab (or dostarlimab) for MSI-H/dMMR and pembrolizumab for TMB-H, olaparib for germline BRCA1/2 (maintenance after platinum), larotrectinib/entrectinib for NTRK fusions, selpercatinib for RET fusions, dabrafenib + trametinib for BRAF V600E, erdafitinib for FGFR2 alterations, fam-trastuzumab deruxtecan for HER2-positive disease, zenocutuzumab for NRG1 fusion-positive disease, and (in recent NCCN versions) KRAS G12C inhibitors (adagrasib/sotorasib), several of these after prior systemic therapy. Integrate supportive care throughout: relieve obstructive jaundice with an endoscopic self-expanding metal stent in non-operative or neoadjuvant pathways, but do NOT perform routine preoperative biliary drainage before planned upfront resection; treat exocrine insufficiency with pancreatic enzyme replacement titrated to symptoms (common starting dose ~40,000-50,000 units of lipase with main meals, roughly half with snacks, increased as needed); manage refractory pain with celiac plexus neurolysis or palliative RT; relieve gastric outlet obstruction with surgical or EUS-guided gastrojejunostomy (or enteral stenting); and provide VTE prophylaxis, nutritional support, and early palliative care.