AIMS:Accurate determination of tumour size is critical for pT staging in pancreatic ductal adenocarcinoma (PDAC), yet gross measurement alone often underestimates the true tumour extent because of the tumour's ill-defined and infiltrative nature. This study aimed to evaluate the diagnostic and prognostic value of incorporating microscopic rectification into tumour size assessment in PDAC. METHODS AND RESULTS:A total of 342 therapy-naïve pancreatoduodenectomies were analysed using a grossing protocol that includes separate sampling of anterior and posterior soft tissues via the 'orange-peeling' technique to retrieve lymph nodes and document soft tissue involvement. Peripancreatic soft tissue involvement was present in 91% of cases, and isolated microscopic foci distant from the main mass in 48%. Of the 266 tumours grossly classified as pT1/T2 (≤4 cm), 39 (14%) showed carcinoma in both anterior and posterior soft tissues, and were reclassified as pT3. This subset showed significantly worse survival (P = 0.04) and higher nodal positivity (87% versus 69%, P = 0.02) than the remaining pT2 cases, comparable to conventional pT3 tumours (86%, P = 0.77). Multivariable Cox regression adjusted for age, sex, nodal status, margin, and lymphovascular/perineural invasion confirmed the survival disadvantage of this subgroup. Reclassification yielded a more balanced distribution of T categories (pT2 66% → 52%, pT3 22% → 34%) and modestly improved prognostic discrimination (C-index: 0.592 versus 0.574). CONCLUSIONS:This study elucidates that PDAC frequently extends beyond the visible mass ('horses out of the barn' phenomenon); peripancreatic soft tissue involvement is common, and gross size often underestimates the true tumour extent, making microscopic correction crucial. Approximately one in six pT1/T2 tumours (≤4 cm) shows carcinoma in both anterior and posterior soft tissues and behave like pT3 in outcomes and nodal status. Therefore, gross-micro rectification is essential to avoid understaging, particularly for T2 tumours. The orange-peeling protocol should classify tumours with foci in both anterior and posterior soft tissues as pT3, while other approaches may employ mapping techniques to enable microscopic reconstruction and biologically accurate staging.

A distinct type of pancreatic carcinoma (n=31; 6% of adenocarcinomas) is described, distinguished from conventional pancreatic ductal adenocarcinoma (PDAC) by: (1) solid/undifferentiated (sheet-like, stroma-poor) carcinomas lacking features of other entities (no osteoclasts, microsatellite stable, INI-1 retained, nonkeratinizing squamous <30%), often admixed with ordinary PDAC; (2) radiology/gross showing central necrosis/demarcation mimicking nonductal neoplasms, not scirrhous like PDAC; (3) marked intratumoral heterogeneity with divergent patterns, including basal/squamoid (81%), solid sheets punctuated with megavacuoles (77%), clear cell (68%), mucoepidermoid-like (36%), sarcomatoid (36%), and occasional choriocarcinomatous or angiosarcomatous patterns, and some with carcinomatous vasculitis; (4) cellular anaplasia with pleomorphic giant cells (55%), multinucleated nonosteoclastic (32%), and rhabdoid-like (32%); (5) immunohistochemically (n=16) consistently showing a basal phenotype with common GATA6 loss/depletion and/or CK5/6, p40, or p63 expression; (6) molecular-genetic profile (n=13) showing altered frequencies: ARID1A (31% vs. 4%) and CDKN2A/p16 (92% vs. 30%) alterations, universal KRAS mutations with enrichment in KRAS G12D, frequent TP53, and lower SMAD4 loss (8% vs. 55%). Limited follow-up suggests comparable or more favorable outcomes. In conclusion, this is a distinct type of carcinoma in the pancreas that is prone to being misdiagnosed as nonductal/non-PDAC cancers. It is the first pancreatic carcinoma type in which a basal molecular phenotype can be indicated clinically by both imaging and histopathology, with major potential management implications (as it is also enriched in actionable targets like ARID1A). Recognition of this category is critical for cancer research, as it offers an invaluable group to study plasticity, stroma versatility, necrosis mechanisms, and the basal type in pancreatic cancer.

A distinct type of pancreatic carcinoma (n=31; 6% of adenocarcinomas) is described, distinguished from conventional pancreatic ductal adenocarcinoma (PDAC) by: (1) solid/undifferentiated (sheet-like, stroma-poor) carcinomas lacking features of other entities (no osteoclasts, microsatellite stable, INI-1 retained, nonkeratinizing squamous <30%), often admixed with ordinary PDAC; (2) radiology/gross showing central necrosis/demarcation mimicking nonductal neoplasms, not scirrhous like PDAC; (3) marked intratumoral heterogeneity with divergent patterns, including basal/squamoid (81%), solid sheets punctuated with megavacuoles (77%), clear cell (68%), mucoepidermoid-like (36%), sarcomatoid (36%), and occasional choriocarcinomatous or angiosarcomatous patterns, and some with carcinomatous vasculitis; (4) cellular anaplasia with pleomorphic giant cells (55%), multinucleated nonosteoclastic (32%), and rhabdoid-like (32%); (5) immunohistochemically (n=16) consistently showing a basal phenotype with common GATA6 loss/depletion and/or CK5/6, p40, or p63 expression; (6) molecular-genetic profile (n=13) showing altered frequencies: ARID1A (31% vs. 4%) and CDKN2A/p16 (92% vs. 30%) alterations, universal KRAS mutations with enrichment in KRAS G12D, frequent TP53, and lower SMAD4 loss (8% vs. 55%). Limited follow-up suggests comparable or more favorable outcomes. In conclusion, this is a distinct type of carcinoma in the pancreas that is prone to being misdiagnosed as nonductal/non-PDAC cancers. It is the first pancreatic carcinoma type in which a basal molecular phenotype can be indicated clinically by both imaging and histopathology, with major potential management implications (as it is also enriched in actionable targets like ARID1A). Recognition of this category is critical for cancer research, as it offers an invaluable group to study plasticity, stroma versatility, necrosis mechanisms, and the basal type in pancreatic cancer.

The guidelines recently recognized the intra-ampullary papillary tubular neoplasm (IAPN) as a distinct tumor entity. However, the data on IAPN and its distinction from other ampullary tumors remain limited. A detailed clinicopathologic analysis of 72 previously unpublished IAPNs was performed. The patients were: male/female=1.8; mean age=67 years (range: 42 to 86 y); mean size=2.3 cm. Gross-microscopic correlation was crucial. From the duodenal perspective, the ampulla was typically raised symmetrically, with a patulous orifice, and was otherwise covered by stretched normal duodenal mucosa. However, in 6 cases, the protrusion of the intra-ampullary tumor to the duodenal surface gave the impression of an "ampullary-duodenal tumor," with the accurate diagnosis of IAPN established only by microscopic correlation illustrating the abrupt ending of the lesion at the edge of the ampulla. Microscopically, the preinvasive component often revealed mixed phenotypes (44.4% predominantly nonintestinal). The invasion was common (94%), typically small (mean=1.2 cm), primarily pancreatobiliary-type (75%), and showed aggressive features (lymphovascular invasion in 66%, perineural invasion in 41%, high budding in 30%). In 6 cases, the preinvasive component was pure intestinal, but the invasive component was pancreatobiliary. LN metastasis was identified in 42% (32% in those with ≤1 cm invasion). The prognosis was significantly better than ampullary-ductal carcinomas (median: 69 vs. 41 months; 3-year: 68% vs. 55%; and 5-year: 51% vs. 35%, P =0.047). In conclusion, unlike ampullary-duodenal carcinomas, IAPNs are often (44.4%) predominantly nonintestinal and commonly (94%) invasive, displaying aggressive features and LN metastasis even when minimally invasive, all of which render them less amenable to ampullectomy. However, their prognosis is still better than that of the "ampullary-ductal" carcinomas, with which IAPNs are currently grouped in CAP protocols (while IAPNs are kindreds of intraductal tumors of the pancreatobiliary tract, the latter represents the ampullary counterpart of pancreatic adenocarcinoma/cholangiocarcinoma).

BACKGROUND:Grade 1/2 PanNETs are mostly managed similarly, typically without any adjunct treatment with the belief that their overall metastasis rate is low. In oncology literature, Ki67-index of 10% is increasingly being used as the cutoff in stratifying patients to different protocols, although there are no systematic pathology-based studies supporting this approach. METHODS:Ki67-index was correlated with clinicopathologic parameters in 190 resected PanNETs. A validation cohort (n = 145) was separately analyzed. RESULTS:In initial cohort, maximally selected rank statistics method revealed 12% to be the discriminatory cutoff (close to 10% rule of thumb). G2b cases had liver/distant metastasis rate of almost threefold higher than that of G2a and showed significantly higher frequency of all histopathologic signs of aggressiveness (tumor size, perineural/vascular invasion, infiltrative growth pattern, lymph node metastasis). In validation cohort, these figures were as striking. When all cases were analyzed together, compared with G1, the G2b category had nine times higher liver/distant metastasis rate (6.1 vs. 58.5%; p < 0.001) and three times higher lymph node metastasis rate (20.5 vs. 65.1%; p < 0.001). CONCLUSIONS:G2b PanNETs act very similar to G3, supporting management protocols that regard them as potential therapy candidates. Concerning local management, metastatic behavior in G2b cases indicate they may not be as amenable for conservative approaches, such as watchful waiting or enucleation. This substaging should be considered into diagnostic guidelines, and clinical trials need to be devised to determine the more appropriate management protocols for G2b (10% to ≤ 20%) group, which shows liver/distant metastasis in more than half of the cases, which at minimum warrants closer follow-up.

Context.-The nature and associations of gallbladder (GB) "adenomyoma"(AM) remain controversial. Some studies have attributed up to 26% of GB carcinoma to AMs. Objective.-To examine the true frequency, clinicopathologic characteristics, and neoplastic changes in GB AM. Design.-Cholecystectomy cohorts analyzed were 1953 consecutive cases, prospectively with specific attention to AM; 2347 consecutive archival cases; 203 totally embedded GBs; 207 GBs with carcinoma; and archival search of institutions for all cases diagnosed as AM. Results.-Frequency of AM was 9.3% (19 of 203) in totally submitted cases but 3.3% (77 of 2347) in routinely sampled archival tissue. A total of 283 AMs were identified, with a female to male ratio =1.9 (177:94) and mean size = 1.3 cm (range, 0.3-5.9). Most (96%, 203 of 210) were fundic, with formed nodular trabeculated submucosal thickening, and were difficult to appreciate from the mucosal surface. Four of 257 were multifocal (1.6%), and 3 of 257 (1.2%) were extensive ("adenomyomatosis"). Dilated glands (up to 14 mm), often radially converging to a point in the mucosa, were typical. Muscle was often minimal, confined to the upper segment. Nine of 225 (4%) revealed features of a duplication. No specific associations with inflammation, cholesterolosis, intestinal metaplasia, or thickening of the uninvolved GB wall were identified. Neoplastic change arising in AM was seen in 9.9% (28 of 283). Sixteen of 283 (5.6%) had mural intracholecystic neoplasm; 7 of 283 (2.5%) had flat -type high-grade dysplasia/carcinoma in situ. Thirteen of 283 cases had both AM and invasive carcinoma (4.6%), but in only 5 of 283 (1.8%), carcinoma arose from AM (invasion was confined to AM, and dysplasia was predominantly in AM). Conclusions.-AMs have all the features of a malformative developmental lesion, and may not show a significant muscle component (ie, the name "adeno-myoma"is partly a misnomer). While most are innocuous, some pathologies may arise in AMs, including intracholecystic neoplasms, flattype high-grade dysplasia or carcinoma in situ, and invasive carcinoma (1.8%, 5 of 283). It is recommended that gross examination of GBs include serial slicing of the fundus for AM detection and total submission if one is found.

Grade 1/2 PanNETs are mostly managed similarly, typically without any adjunct treatment with the belief that their overall metastasis rate is low. In oncology literature, Ki67-index of 10

BACKGROUND:The cause of most pancreatic and periampullary cancers (PAC) is unknown. Recently, anatomic variations such as pancreatobiliary maljunction have been recognized as risk factors, similar to Barrett-related gastro-esophageal cancers.METHODS:Pre-operative MRI from 860 pancreatic/biliary resections, including 322 PACs, were evaluated for low-union (cystic duct joining the common hepatic duct inside of the pancreas or within 5 mm of the pancreatic border) RESULTS: Low-union, seen <10% of the population, was present in 44% of PACs (73% distal bile duct/cholangiocarcinoma, 42% pancreatic head, and 34% ampullary). It was significantly lower(11%) in conditions without connection to the ductal system (thus not exposed to the ductal/biliary tract contents), namely mucinous cystic neoplasms and intrahepatic cholangiocarcinomas(p < 0.0001). Intra-pancreatic type low-union was seen in 16% of PACs versus 2% of controls(p < 0.0001).DISCUSSION:This study establishes an association between low-union and PACs, and points to an anatomy-induced chemical/bilious carcinogenesis. This may explain why most pancreas cancers are in the head. It is possible that the same chemical milieu, caused by conditions other than low-union/insertion, may also play a role in the remaining half of PACs. This opens various treatment opportunities including milieu modifications (chemoprevention), focused screening of at-risk patients, and early detection with possible corrective actions.

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.

Intracholecystic neoplasms (ICNs) (pyloric gland adenomas and intracholecystic papillary neoplasms, collectively also called intracholecystic papillary/tubular neoplasms) form multifocal, extensive proliferations on the gallbladder mucosa and have a high propensity for invasion (>50%). In this study, 19 examples of a poorly characterized phenomenon, mural papillary mucinous lesions that arise in adenomyomatous nodules and form localized ICNs, were analyzed. Two of these were identified in 1750 consecutive cholecystectomies reviewed specifically for this purpose, placing its incidence at 0.1%. Median age was 68 years. Unlike other gallbladder lesions, these were slightly more common in men (female/male=0.8), and 55% had documented cholelithiasis. All were characterized by a compact multilocular, demarcated, cystic lesion with papillary proliferations and mucinous epithelial lining. The lesions’ architecture, distribution, location, and typical size were suggestive of evolution from an underlying adenomyomatous nodule. All had gastric/endocervical-like mucinous epithelium, but 5 also had a focal intestinal-like epithelium. Cytologic atypia was graded as 1 to 3 and defined as 1A: mucinous, without cytoarchitectural atypia (n=3), 1B: mild (n=7), 2: moderate (n=2), and 3: severe atypia (n=7, 3 of which also had invasive carcinoma, 16%). Background gallbladder mucosal involvement was absent in all but 2 cases, both of which had multifocal papillary mucosal nodules. In conclusion, these cases highlight a distinct clinicopathologic entity, that is, mural ICNs arising in adenomyomatous nodules, which, by essentially sparing the “main” mucosa, not displaying “field-effect/defect” phenomenon, and only rarely (16%) showing carcinomatous transformation, are analogous to pancreatic branch duct intraductal papillary mucinous neoplasms.

Intracholecystic neoplasms (ICNs) (pyloric gland adenomas and intracholecystic papillary neoplasms, collectively also called intracholecystic papillary/tubular neoplasms) form multifocal, extensive proliferations on the gallbladder mucosa and have a high propensity for invasion (>50%). In this study, 19 examples of a poorly characterized phenomenon, mural papillary mucinous lesions that arise in adenomyomatous nodules and form localized ICNs, were analyzed. Two of these were identified in 1750 consecutive cholecystectomies reviewed specifically for this purpose, placing its incidence at 0.1%. Median age was 68 years. Unlike other gallbladder lesions, these were slightly more common in men (female/male=0.8), and 55% had documented cholelithiasis. All were characterized by a compact multilocular, demarcated, cystic lesion with papillary proliferations and mucinous epithelial lining. The lesions' architecture, distribution, location, and typical size were suggestive of evolution from an underlying adenomyomatous nodule. All had gastric/endocervical-like mucinous epithelium, but 5 also had a focal intestinal-like epithelium. Cytologic atypia was graded as 1 to 3 and defined as 1A: mucinous, without cytoarchitectural atypia (n=3), 1B: mild (n=7), 2: moderate (n=2), and 3: severe atypia (n=7, 3 of which also had invasive carcinoma, 16%). Background gallbladder mucosal involvement was absent in all but 2 cases, both of which had multifocal papillary mucosal nodules. In conclusion, these cases highlight a distinct clinicopathologic entity, that is, mural ICNs arising in adenomyomatous nodules, which, by essentially sparing the "main" mucosa, not displaying "field-effect/defect" phenomenon, and only rarely (16%) showing carcinomatous transformation, are analogous to pancreatic branch duct intraductal papillary mucinous neoplasms.

Distal common bile duct carcinoma is a poorly characterized entity for reasons such as variable terminology and difficulty in determining site of origin of intrapancreatic lesions. We compared clinicopathologic features of pancreatobiliary-type adenocarcinomas within the pancreas, but arising from the distal common bile duct, with those of pancreatic and ampullary origin. Upon careful review of 1017 pancreatoduodenectomy specimens with primary adenocarcinoma, 52 (5%) qualified as intrapancreatic distal common bile duct carcinoma. Five associated with an intraductal papillary neoplasm were excluded; the remaining 47 were compared to 109 pancreatic ductal adenocarcinomas and 133 ampullary carcinomas. Distal common bile duct carcinoma patients had a younger median age (58 years) than pancreatic ductal adenocarcinoma patients (65 years) and ampullary carcinoma patients (68 years). Distal common bile duct carcinoma was intermediate between pancreatic ductal adenocarcinoma and ampullary carcinoma with regard to tumor size and rates of node metastases and margin positivity. Median survival was better than for pancreatic ductal adenocarcinoma (P=0.0010) but worse than for ampullary carcinoma (P=0.0006). Distal common bile duct carcinoma often formed an even band around the common bile duct and commonly showed intraglandular neutrophil-rich debris and a small tubular pattern. Poor prognostic indicators included node metastasis (P=0.0010), lymphovascular invasion (P=0.0299), and margin positivity (P=0.0069). Categorizing the tumors based on size also had prognostic relevance (P=0.0096), unlike categorization based on anatomic structures invaded. Primary distal common bile duct carcinoma is seen in younger patients than pancreatic ductal adenocarcinoma or ampullary carcinoma. Its prognosis is significantly better than pancreatic ductal adenocarcinoma and worse than ampullary carcinoma, at least partly because of differences in clinical presentation. Use of size-based criteria for staging appears to improve its prognostic relevance. Invasive pancreatobiliary-type distal common bile duct carcinomas are uncommon in the West and have substantial clinicopathologic differences from carcinomas arising from the pancreas and ampulla.

Pancreaticoduodenectomy (PD) specimens present a challenge for surgical pathologists because of the relative rarity of these specimens, combined with the anatomic complexity. Here, we describe our experience on the orientation, dissection, and sampling of PD specimens for a more practical and accurate evaluation of pancreatic, distal common bile duct (CBD), and ampullary tumors. For orientation of PDs, identification of the "trapezoid," created by the vascular bed at the center, the pancreatic neck margin on the left, and the uncinate margin on the right, is of outmost importance in finding all the pertinent margins of the specimen including the CBD, which is located at the upper right edge of this trapezoid. After orientation, all the margins can be sampled. We submit the uncinate margin entirely as a perpendicular inked margin because this adipose tissue-rich area often reveals subtle satellite carcinomas that are grossly invisible, and, with this approach, the number of R1 resections has doubled in our experience. Then, to ensure proper identification of all lymph nodes (LNs), we utilize the orange-peeling approach, in which the soft tissue surrounding the pancreatic head is shaved off in 7 arbitrarily defined regions, which also serve as shaved samples of the so-called "peripancreatic soft tissue" that defines pT3 in the current American Joint Committee on Cancer TNM. With this approach, our LN count increased from 6 to 14 and LN positivity rate from 50% to 73%. In addition, in 90% of pancreatic ductal adenocarcinomas there are grossly undetected microfoci of carcinoma. For determination of the primary site and the extent of the tumor, we believe bisectioning of the pancreatic head, instead of axial (transverse) slicing, is the most revealing approach. In addition, documentation of the findings in the duodenal surface of the ampulla is crucial for ampullary carcinomas and their recent site-specific categorization into 4 categories. Therefore, we probe both the CBD and the pancreatic duct from distal to the ampulla and cut the pancreatic head to the ampulla at a plane that goes through both ducts. Then, we sample the bisected pancreatic head depending on the findings of the case. For example, for proper staging of ampullary carcinomas, it is imperative to take the sections perpendicular to the duodenal serosa at the "groove" area, as ampullary carcinomas often extend to this region. Amputative (axial) sectioning of the ampulla, although good for documentation of the peri-Oddi spread of the intra-ampullary tumors, unfortunately disallows documentation of mucosal spread of the papilla of Vater tumors (those arising from the edge of the ampulla, where the ducts transition to duodenal mucosa and extending) into the neighboring duodenum. Axial sectioning also often fails to document tumor spread to the "groove" area. In conclusion, knowledge of the gross characteristics of the anatomic hallmarks is essential for proper dissection of PD specimens. The approach described above allows practical and accurate documentation and staging of pancreas, distal CBD, and ampullary cancers.

Pancreaticoduodenectomy (PD) specimens present a challenge for surgical pathologists because of the relative rarity of these specimens, combined with the anatomic complexity. Here, we describe our experience on the orientation, dissection, and sampling of PD specimens for a more practical and accurate evaluation of pancreatic, distal common bile duct (CBD), and ampullary tumors. For orientation of PDs, identification of the “trapezoid,” created by the vascular bed at the center, the pancreatic neck margin on the left, and the uncinate margin on the right, is of outmost importance in finding all the pertinent margins of the specimen including the CBD, which is located at the upper right edge of this trapezoid. After orientation, all the margins can be sampled. We submit the uncinate margin entirely as a perpendicular inked margin because this adipose tissue–rich area often reveals subtle satellite carcinomas that are grossly invisible, and, with this approach, the number of R1 resections has doubled in our experience. Then, to ensure proper identification of all lymph nodes (LNs), we utilize the orange-peeling approach, in which the soft tissue surrounding the pancreatic head is shaved off in 7 arbitrarily defined regions, which also serve as shaved samples of the so-called “peripancreatic soft tissue” that defines pT3 in the current American Joint Committee on Cancer TNM. With this approach, our LN count increased from 6 to 14 and LN positivity rate from 50% to 73%. In addition, in 90% of pancreatic ductal adenocarcinomas there are grossly undetected microfoci of carcinoma. For determination of the primary site and the extent of the tumor, we believe bisectioning of the pancreatic head, instead of axial (transverse) slicing, is the most revealing approach. In addition, documentation of the findings in the duodenal surface of the ampulla is crucial for ampullary carcinomas and their recent site-specific categorization into 4 categories. Therefore, we probe both the CBD and the pancreatic duct from distal to the ampulla and cut the pancreatic head to the ampulla at a plane that goes through both ducts. Then, we sample the bisected pancreatic head depending on the findings of the case. For example, for proper staging of ampullary carcinomas, it is imperative to take the sections perpendicular to the duodenal serosa at the “groove” area, as ampullary carcinomas often extend to this region. Amputative (axial) sectioning of the ampulla, although good for documentation of the peri-Oddi spread of the intra-ampullary tumors, unfortunately disallows documentation of mucosal spread of the papilla of Vater tumors (those arising from the edge of the ampulla, where the ducts transition to duodenal mucosa and extending) into the neighboring duodenum. Axial sectioning also often fails to document tumor spread to the “groove” area. In conclusion, knowledge of the gross characteristics of the anatomic hallmarks is essential for proper dissection of PD specimens. The approach described above allows practical and accurate documentation and staging of pancreas, distal CBD, and ampullary cancers.