In many instances, the presence of a pancreatic cancer may not be visible on external inspection of a pancreatoduodenectomy specimen. Occasionally, however, the tumour may cause bulging of a surface or irregularity of the duodenal mucosa or papilla of Vater. In particular, narrowing of the SMV groove or irregularity of its surface may indicate the presence of a tumour. In a similar way, the presence of an adherent segment or sleeve resection of a vein (SMV or portal vein) or artery (e.g. the hepatic artery) indicates tumour infiltration. Palpation will usually confirm the presence of an indurated tumour mass.

External examination can also reveal a variety of other pathological conditions, such as a tumour of the papilla or ampulla of Vater, dilatation of the papilla with oozing of mucus in case of intraductal papillary mucinous neoplasia or a rare annular pancreas that surrounds the entire duodenal circumference.

Orientation of distal pancreatectomy specimens is straightforward, especially as cancer specimens always include the spleen. Further helpful with specimen orientation is the presence of the splenic vessels, which run along the superior border of the pancreatic body and tail (Fig. 5.2).

Inking of the specimen surfaces serves a dual purpose. It helps with orientation during macroscopic and microscopic examination, and it allows unequivocal microscopic identification of the true specimen surface, which is important for accurate margin assessment.

Inking is easiest done after specimen fixation, because inks stick better to fixed than fresh tissue surfaces. So-called bleeding of colours can be reduced by spraying 10% acetic acid onto the freshly applied ink. Should inking of a fresh specimen be required, the use of ground dry pigment dissolved in acetone may be considered. The use of acetone as a dissolvent ensures rapid drying of the dye, which reduces bleeding of colours.

The various specimen surfaces should be inked in different colours according to a locally agreed colour code. In pancreatoduodenectomy specimens, five different surfaces are discerned, whose identification and examination is part of the margin status assessment (Fig. 5.3) [9–11]. The surfaces of the pancreatic head are – as outlined in Sect. 5.2.1.1 – the anterior and posterior surface, the SMV groove and the SMA surface. Although the anterior surface is not a true resection margin but an anatomical surface that faces the lesser sac, inclusion of this surface in the assessment is important, as involvement of this surface increases the risk of cancer recurrence [12]. A further margin consists of the circumferential surface of the extrapancreatic common bile duct. Examination of the various specimen surfaces and resection margins is discussed in detail in Sect. 5.9.

In distal pancreatectomy specimens, two surfaces are discerned and inked: the anterior and posterior surface [10, 11]. If the transection margin of the splenic vessels is of particular concern (Fig. 5.2), this small area may also be inked in a separate colour, such that it can be easily identified during specimen dissection, tissue sampling and microscopic examination.

Pancreatic specimens resulting from an extended resection include one or more additional structures or organs, e.g. a part of the SMV, (meso-)colon or small bowel in extended pancreatoduodenectomy specimens, and the left adrenal gland, part of the stomach or left colon in extended distal pancreatectomy specimens. In such instances, additional surfaces or resection margins must be inked, depending on the individual case.

For practical purposes, it is best to carefully remove without tissue disruption any surgical sutures, clips or staples prior to inking, as the presence of these may render specimen dissection difficult.

Specimen dissection takes a central place in the macroscopic examination process. Its purpose is to reveal lesions and display them in a way that is conducive to accurate description and assessment as well as optimal tissue sampling. Currently, three dissection techniques are being used worldwide: the bi- or multivalving technique, the bread loaf slicing approach and the axial slicing technique [9, 10]. The principal difference between these three dissection techniques is the plane of sectioning. In the bi- or multivalving technique, the specimen is sliced along the plane that is defined by probes inserted in the main pancreatic duct and common bile duct (Fig. 5.4). According to the bread loaf slicing technique, the specimen is sliced along a plane that is parallel to the transection margin of the pancreatic neck (Fig. 5.5). With the axial slicing technique, pancreatoduodenectomy specimens are serially sliced in the axial plane, i.e. along the plane that is perpendicular to the longitudinal axis of the descending part of the duodenum (Fig. 5.6). It is the same plane as the one that is used for computerized tomography (CT) imaging of the pancreas. The following sections will provide a detailed description of the axial slicing technique for pancreatoduodenectomy specimens and discuss the advantages of this technique compared to other approaches. Dissection of distal, total and extended pancreatectomy specimens will be discussed separately.

The aim of the macroscopic examination of dissected specimens is to obtain an accurate record of the tumour: the appearance of the tumour, its size and extent, and its exact location and relationship to anatomical structures, specimen surfaces and margins. Furthermore, assessment of the relationship of the tumour to anatomical structures other than those of relevance for T-staging of pancreatic cancer [18, 19] is of particular interest to surgical and radiology colleagues regarding the preoperative assessment of resectability and patient selection. Equally important, the exact location of the tumour with respect to the bile duct, ampulla and duodenum is crucial for the identification of the cancer origin. Indeed, the distinction of pancreatic ductal adenocarcinoma from cancer of the common bile duct, ampulla or duodenum is primarily determined by the localization of the centre of the tumour mass, a finding that is appreciated macroscopically and confirmed microscopically [3]. The following sections provide guidance for the identification of such anatomical structures.