- Email: [email protected]
The pancreaticoduodenectomy
FROM THE GROSS ROOM
The Pancreaticoduodenectomy E. Scott Young, PA, and Claudia Y. Castro, MD
T
HE pancreaticoduodenectomy (Fig 1) is a complex surgical specimen that is most intimately associated with Dr Allen O. Whipple, a surgeon who ultimately developed the surgical procedure commonly used today for the radical resection of the duodenum, distal common bile duct, and head of pancreas. He performed the first successful one-stage procedure in 1941.1 The first resections were performed by Codivilla in 1898 and Halsted in 1899. The surgical procedures used by modern oncology surgeons are modifications of the methods developed by these pioneering surgeons. Indications for Surgical Intervention Primary indications to perform this procedure include tumors of the head of the pancreas, distal common bile duct, and the peri-ampullary region. Other indications include chronic pancreatitis, severe trauma at the level of the head of the pancreas and duodenum, and common bile duct obstruction. In case 1 the patient was thought to have a pancreatic carcinoma (Fig 2). Upon sectioning, it became readily apparent that there was a single calculus that was obstructing the pancreatic duct. There was subsequent abscess formation, proximal to the area in which the calculus was embedded. In case 2 a mass within the head of the pancreas can be seen to the right of the common bile duct. This adenocarcinoma was compressing the adjacent bile duct causing cholestasis (Fig 3). Gross Constituents The gross constituents of the pancreatoduodenectomy specimen usually include five compo-
From the Department of Pathology, the University of Alabama at Birmingham, AL. Address reprint requests to Scott Young, MD, Department of Pathology, University of Alabama at Birmingham, Kracke Bldg, Birmingham, AL 35294. Copyright 2002, Elsevier Science (USA). All rights reserved. 1092-9134/02/0603-0008$35.00/0 doi:10.1053/adpa.2002.32382
188
nents: (1) distal one third of stomach with or without the right half of the greater omentum; (2) first and second portions of the duodenum, including the ampulla of vater; (3) the bile duct; (4) the head of pancreas (which often includes the uncinate process, or a portion thereof); and (5) the peripancreatic lymph nodes. There are many variations to this surgical procedure that may limit or involve adjacent anatomical structures. The distal portion of the stomach may or not be included. The gallbladder is usually submitted as a separate specimen. The operation consists basically of a partial gastrectomy, duodenectomy, and partial pancreatectomy. One of the most difficult steps in this procedure is peeling off the uncinate process of the pancreas from the adjacent vasculature (mesenteric artery and portal vein). Figure 4 is an intraoperative photo of the pancreas after being carefully dissected from the portal vein. Specimen Preparation Because of the complex nature of this type of specimen, it is important to properly prepare it before making the gross evaluation, paying particular attention to the pancreatic and bile ducts as they approach the ampulla. To prepare the specimen you must first properly open and fix it using the following steps: 1. Open the stomach and segment of duodenum length-wise using scissors. The stomach should be opened along the greater curvature and the anterior wall of the pylorus and the incision should continue along the duodenum, at the opposite side of the ampulla. Frequently, upon opening the duodenum, you will find a stent within the ampulla. If the stent is plastic, you may carefully remove it to further prepare the specimen for fixation. However, if the stent is a metallic mesh, you should leave it in place within the bile duct until properly fixed. The mesh wire stent is designed to dilate the bile duct and is usually embedded within the bile
Annals of Diagnostic Pathology, Vol 6, No 3 (June), 2002: pp 188-193
The Pancreaticoduodenectomy
Figure 1. Pancreatoduodenectomy specimen that includes the distal third of the stomach, the duodenum, the head of the pancreas, the common bile duct, and the gallbladder. Notice the marked dilatation of the common bile duct caused by a small ampullary carcinoma.
Figure 2. Common bile duct and its opening at the ampulla the vater. There is a large ulcer associated with and abscess secondary to a large impacted calculus.
189
Figure 3. Adenocarcinoma of the head of the pancreas producing a common bile duct stricture.
duct epithelium. Proper fixation should occur before removal (method to be described later) so the epithelium is mostly preserved. You should note the type of stent and site of placement within the body of your gross description. 2. Identify the common bile duct at the junction of the pancreas and proximal duodenum. Shave the margin and introduce a probe into the duct until it exits into the ampulla of Vater. 3. Identify the main pancreatic duct. Shave the margin and gently insert a probe into the duct until it exits into the ampulla of Vater. With many pancreatic neoplasms, you may only be able to probe a small segment of the pancreatic
Figure 4. Intra-operative photo of the pancreas after being carefully dissected from the portal vein.
190
Young and Castro
duct. Make sure you note the length of duct that is probable. If the pancreatic duct margin is difficult to identify, make two or three serial sections starting at the pancreatic margin to find the duct. If the duct is found, put a probe and advance to the ampulla. In the case of a nonprobable pancreatic duct, probe from the ampulla of vater or the mucosa around the ampulla for the opening of the pancreatic duct. Sometimes the pancreatic duct may open more distally than the bile duct and this opening may simulate an edematous mucosa fold (duct of Santorini). With probes in place (bile duct and pancreatic duct) line up the probes and section the specimen along the length of the two ducts. This bisects the ampulla and shows the relationship of the tumor to the ampulla, the duodenal mucosa, the common bile duct, the pancreatic duct, and the pancreatic parenchyma. 5. Ink the anterior and posterior surface of the pancreas with different colors. 6. Allow the specimen to fix in 10% neutral buffered formalin for a minimum of 2 hours. After fixation, evaluate the main pathologic process and look for lymph nodes. In the case of an ampullary or bile duct tumor, you may elect to fix the specimen overnight. In the case that the common bile duct has a metallic wire stent in place, cut the duct carefully using a scalpel. When the scalpel reaches the stent, carefully peel the stent off from the lumen of the bile duct. Proper fixation before sectioning will preserve much of the bile duct epithelium. Lymph Nodes of Pancreas There is controversy as to how many lymph nodes should be found in a pancreatoduodenectomy specimen. According to the American Joint Committee on Cancer,2 10 or more lymph nodes should be examined. The best policy is to spend time making sure that you find as many lymph nodes as possible, because lymph node involvement is one of the most important prognostic indicators. Five groups of lymph nodes are included in a Whipple specimen3,4 and include: Antral-omental lymph nodes: lymph nodes of greater and lesser curvatures of the stomach. Superior pancreatic: lymph nodes localized be-
tween the pancreas and the pylorus and first portion of duodenum. Inferior pancreatic: lymph nodes localized between the inferior border pancreas and the duodenum. Pancreato-duodenal (anterior and posterior): lymph nodes between the head of the pancreas and second portion of duodenum. Common bile duct (portal): lymph nodes around the common bile duct, cystic duct. Gross Description It is important to have a standardized system for the pathologic evaluation of the pancreatoduodenectomy to avoid omissions in the gross description. A good way to organize the dictation is by paragraphs. In most gross descriptions you will have five paragraphs. The first paragraph describes the anatomic components of the specimen and describes the dimensions of each component. In the case of the pancreatoduodenectomy, you should record the dimension of the stomach (length of greater curvature, lesser curvature, circumference, and wall thickness), greater omentum (size in cms), duodenum (length and diameter), head of pancreas (three dimensions), and common bile duct (length and diameter). The pancreas should be described noting all anatomic landmarks. Note the condition of the uncinate process (if included) as the furrow that you will see is where the pancreas has been reflected from the adjacent portal vein. The second paragraph describes the main pathology. In the case of a tumor describe: (1) size, (2) site of origin, (3) tumor characteristics (color, consistency, fungating, flat, ulcerated, nonulcerated, presence of necrosis, hemorrhage, cyst formation), (4) margins (well defined, pushing, ill-defined), (5) distance from margins, and (6) obstruction of ducts or extension into duodenal wall. Some pancreatic tumors are difficult to identify because they only partially efface the normal lobular architecture of the pancreas. The best way to identify them is around a bile duct or pancreatic duct stricture. The third paragraph describes any additional pathology: fibrosis of pancreatic parenchyma or fat necrosis. Note that distal duodenal segment usually has a congested hyperemic appearance which is an artifact of the surgical procedure. This part of the gross description can also be used to describe normal pertinent information like the appearance of
The Pancreaticoduodenectomy
191
the ampulla of vater, the bile duct patency, or stent placement. The fourth paragraph describes the ink code (anterior, blue, posterior, black) and any other procedure like gross photography. The fifth paragraph describes the block summary, which is a detailed description of the tissue sections obtained and the way they were obtained (shave, perpendicular or radial sections). An example of the gross description of an ampullary tumor (Figs 5 and 6) will include: Received fresh in a single container and labeled with patient’s name, medical record number and “Whipple” is a pancreatoduodenectomy specimen that includes a portion of the distal stomach (10.0 cm in length ⫻ 9.0 cm in diameter ⫻ 0.5 cm wall thickness) with attached, unremarkable omentum (19.0 ⫻ 9.0 ⫻ 0.5 cms), first and second portions of duodenum (30.5 cm in length with average diameter of 3.5 cm.), head of pancreas and uncinate process (7.5 ⫻ 6.5 ⫻ 4.5 cm) and segment of markedly dilated common bile duct (4 cms in length ⫻ 3.2 cm in diameter). In the region of the ampulla there is a firm, tan-white, polypoid, partially ulcerated infiltrative mass that measures 3.2 ⫻ 2.2 ⫻ 2.0 cm (Fig 5). This mass is involving and completely obstructing the common bile duct at the ampulla and is partially obstructing the pancreatic duct (Fig 6). The tumor is localized at 3.5 and 3.0 cms from the surgical resection margin of the bile duct and the pancreas, respectively. The tumor invades the wall of the duodenum, but do not invade the head of the pancreas.
Figure 6. Ampullary carcinoma obstructing the distal portion of the bile duct and the pancreatic duct. (Same case of Fig 5).
The distal bile duct is markedly dilated, covered by an edematous and red mucosa. In the bile duct there is a white plastic stent. The pancreatic parenchyma is firm and lobulated. The gastric mucosa and wall are unremarkable. The distal duodenal mucosa is red and edematous. No other lesions are identified grossly. In the peripancreatic region multiple tan soft lymph nodes measuring from 0.5 to 2.0 cms are identified as follows: two in superior pancreatic region, one in the inferior pancreatic region, two in the pancreato-duodenal area (one anterior, one posterior) and one in the lesser curvature. The anterior pancreato-duodenal lymph node is markedly enlarged measuring 2.0 cm in greatest dimensions. Ink code: blue anterior, black posterior. A gross photograph is taken. Representative sections are submitted, see block summary.
Figure 7 shows another example of an ampullary tumor invading into the bile and pancreatic ducts. Notice the marked dilatation of the proximal common bile duct. Block Summary The standard tissue sections include:
Figure 5. Ampullary carcinoma forming a polypoid partially ulcerated mass in the lumen of the duodenum.
1. Shave section of proximal and distal margins (stomach and duodedum). 2. Shave section of bile duct margin (usually done at frozen section). 3. Shave section of pancreatic neck margin (usually done at frozen section).
192
Young and Castro
Diagnosis The pathology report should include all information that is required for the proper classification and stage of the tumors (TNM). Important issues to asses are:
Figure 7. Small, focally ulcerated ampullary carcinoma obstructing the common bile duct.
4. Perpendicular section of the uncinate margin taken to include the vascular groove. If the neoplasm is close to the uncinate margin, make sure that the section includes tumor. 5. Tumor: if less that 3 cms submit entirely. If larger, submit one per centimeter per tumor. Sections should include relationship of the tumor to pancreas, bile duct, pancreatic duct, ampulla, duodenal wall, and soft tissue margin. 6. Normal pancreas one of two cassettes. 7. Bile duct, random sections. 8. Duodenum, random section. 9. Ampulla of vater. Sections of the ampulla are a must. Lengthwise sections are best and should always include normal duodenal mucosa. 10. Soft tissue. Only the posterior soft tissue is a real margin (retroperitoneum).4 The remaining soft tissue sections are to evaluate extension of the tumor outside of the pancreas. The retroperitoneal margin is defined as the soft tissue margin along the right lateral border of the proximal 3 to 4 cms of the superior mesenteric artery. This important margin is often confused with the soft tissue posterior to the pancreatic head and duodenum. For proper identification, the retroperitoneal margin must be taken at the time of the surgery and sent for frozen section. Identification of this margin of resection is not possible once the gross examination of the specimen has been completed.4 11. Lymph nodes: all lymph nodes are submitted as separate groups.
1. Type of procedure and what structures or organs where present. 2. Tumor type and tumor grade. 3. Tumor location: What is the exact site of origin (pancreas, bile duct, ampulla of Vater, duodenum). Note: it may not be possible to determine the exact site of origin for large tumors, so a detail description of what areas are involved is indicated. 4. Tumor size (in centimeters). 5. Invasion: extension into the duodenum, ampulla of vater, common bile duct, cystic duct, peripancreatic soft tissues, retroperitoneal fat, mesentery, omentum, portal vein, etc. Note that according to the TNM classification in a case of a primary ampullary tumor, if there is pancreatic invasion present, the extent of invasion should be measured in centimeters, information need to separate tumor stage into a T3 or T4 lesions.2 6. Vascular, lymphatic, or perineural invasion. 7. Status of surgical resection margins (pancreatic neck margin, uncinate process margin, retroperitoneal margin, bile duct margin, duodenal and stomach margin). 8. Nodal status and site: Mention number of lymph nodes examined by area and the number of lymph nodes involved. Note that according to the TNM classification, the designation of regional versus distant lymph nodes (N1-3 versus M1) varies according to the primary site of the tumor. A group of lymph nodes that may be considered regional (N1 disease) for a cancer of the head of the pancreas, may be considered distant metastasis (M1) is the tumor is arising from the ampullary region.2 9. Additional pathology: chronic pancreatitis, fibrosis, islet cell hyperplasia, etc. Conclusion The pancreatoduodenectomy is a complex surgical procedure that involves multiple organ systems. A good preparation and careful dissection of the specimen is a must. The gross description should be detail and organized in such a manner that the
The Pancreaticoduodenectomy
reader can visualize in his mind the pathologic process and be able to easily extract the appropriate information to correctly stage the tumor. References 1. Whipple AO: The rationale of radical surgery for cancer of the pancreas and ampullary region. Ann Surg 1941;114:612-615 2. Ampullary of Vater and Exocrine pancreas, in Fleming ID, Cooper JS, Henson DE, et al (ed). AJCC Cancer Staging Manual.
193
Philadelphia, PA, Lippincott Williams & Wilkins,1997, pp 115126 3. Stanley CA, Cleary KR, Abbruzzese JL, et al: The need for standardized pathologic staging of pancreatoduodenectomy specimens. Pancreas1996;12:373-380 4. Evans DB, Abruzzese JL, Rich TA: Cancer of Pancreas, in DeVita VT, Hellman S, Rosenberg SA (eds). Cancer: Principles and Practice of Oncology. Philadelphia, PA, Lippincott –Raven, 1997, pp 1061-1063
The Pancreaticoduodenectomy E. Scott Young, PA, and Claudia Y. Castro, MD
T
HE pancreaticoduodenectomy (Fig 1) is a complex surgical specimen that is most intimately associated with Dr Allen O. Whipple, a surgeon who ultimately developed the surgical procedure commonly used today for the radical resection of the duodenum, distal common bile duct, and head of pancreas. He performed the first successful one-stage procedure in 1941.1 The first resections were performed by Codivilla in 1898 and Halsted in 1899. The surgical procedures used by modern oncology surgeons are modifications of the methods developed by these pioneering surgeons. Indications for Surgical Intervention Primary indications to perform this procedure include tumors of the head of the pancreas, distal common bile duct, and the peri-ampullary region. Other indications include chronic pancreatitis, severe trauma at the level of the head of the pancreas and duodenum, and common bile duct obstruction. In case 1 the patient was thought to have a pancreatic carcinoma (Fig 2). Upon sectioning, it became readily apparent that there was a single calculus that was obstructing the pancreatic duct. There was subsequent abscess formation, proximal to the area in which the calculus was embedded. In case 2 a mass within the head of the pancreas can be seen to the right of the common bile duct. This adenocarcinoma was compressing the adjacent bile duct causing cholestasis (Fig 3). Gross Constituents The gross constituents of the pancreatoduodenectomy specimen usually include five compo-
From the Department of Pathology, the University of Alabama at Birmingham, AL. Address reprint requests to Scott Young, MD, Department of Pathology, University of Alabama at Birmingham, Kracke Bldg, Birmingham, AL 35294. Copyright 2002, Elsevier Science (USA). All rights reserved. 1092-9134/02/0603-0008$35.00/0 doi:10.1053/adpa.2002.32382
188
nents: (1) distal one third of stomach with or without the right half of the greater omentum; (2) first and second portions of the duodenum, including the ampulla of vater; (3) the bile duct; (4) the head of pancreas (which often includes the uncinate process, or a portion thereof); and (5) the peripancreatic lymph nodes. There are many variations to this surgical procedure that may limit or involve adjacent anatomical structures. The distal portion of the stomach may or not be included. The gallbladder is usually submitted as a separate specimen. The operation consists basically of a partial gastrectomy, duodenectomy, and partial pancreatectomy. One of the most difficult steps in this procedure is peeling off the uncinate process of the pancreas from the adjacent vasculature (mesenteric artery and portal vein). Figure 4 is an intraoperative photo of the pancreas after being carefully dissected from the portal vein. Specimen Preparation Because of the complex nature of this type of specimen, it is important to properly prepare it before making the gross evaluation, paying particular attention to the pancreatic and bile ducts as they approach the ampulla. To prepare the specimen you must first properly open and fix it using the following steps: 1. Open the stomach and segment of duodenum length-wise using scissors. The stomach should be opened along the greater curvature and the anterior wall of the pylorus and the incision should continue along the duodenum, at the opposite side of the ampulla. Frequently, upon opening the duodenum, you will find a stent within the ampulla. If the stent is plastic, you may carefully remove it to further prepare the specimen for fixation. However, if the stent is a metallic mesh, you should leave it in place within the bile duct until properly fixed. The mesh wire stent is designed to dilate the bile duct and is usually embedded within the bile
Annals of Diagnostic Pathology, Vol 6, No 3 (June), 2002: pp 188-193
The Pancreaticoduodenectomy
Figure 1. Pancreatoduodenectomy specimen that includes the distal third of the stomach, the duodenum, the head of the pancreas, the common bile duct, and the gallbladder. Notice the marked dilatation of the common bile duct caused by a small ampullary carcinoma.
Figure 2. Common bile duct and its opening at the ampulla the vater. There is a large ulcer associated with and abscess secondary to a large impacted calculus.
189
Figure 3. Adenocarcinoma of the head of the pancreas producing a common bile duct stricture.
duct epithelium. Proper fixation should occur before removal (method to be described later) so the epithelium is mostly preserved. You should note the type of stent and site of placement within the body of your gross description. 2. Identify the common bile duct at the junction of the pancreas and proximal duodenum. Shave the margin and introduce a probe into the duct until it exits into the ampulla of Vater. 3. Identify the main pancreatic duct. Shave the margin and gently insert a probe into the duct until it exits into the ampulla of Vater. With many pancreatic neoplasms, you may only be able to probe a small segment of the pancreatic
Figure 4. Intra-operative photo of the pancreas after being carefully dissected from the portal vein.
190
Young and Castro
duct. Make sure you note the length of duct that is probable. If the pancreatic duct margin is difficult to identify, make two or three serial sections starting at the pancreatic margin to find the duct. If the duct is found, put a probe and advance to the ampulla. In the case of a nonprobable pancreatic duct, probe from the ampulla of vater or the mucosa around the ampulla for the opening of the pancreatic duct. Sometimes the pancreatic duct may open more distally than the bile duct and this opening may simulate an edematous mucosa fold (duct of Santorini). With probes in place (bile duct and pancreatic duct) line up the probes and section the specimen along the length of the two ducts. This bisects the ampulla and shows the relationship of the tumor to the ampulla, the duodenal mucosa, the common bile duct, the pancreatic duct, and the pancreatic parenchyma. 5. Ink the anterior and posterior surface of the pancreas with different colors. 6. Allow the specimen to fix in 10% neutral buffered formalin for a minimum of 2 hours. After fixation, evaluate the main pathologic process and look for lymph nodes. In the case of an ampullary or bile duct tumor, you may elect to fix the specimen overnight. In the case that the common bile duct has a metallic wire stent in place, cut the duct carefully using a scalpel. When the scalpel reaches the stent, carefully peel the stent off from the lumen of the bile duct. Proper fixation before sectioning will preserve much of the bile duct epithelium. Lymph Nodes of Pancreas There is controversy as to how many lymph nodes should be found in a pancreatoduodenectomy specimen. According to the American Joint Committee on Cancer,2 10 or more lymph nodes should be examined. The best policy is to spend time making sure that you find as many lymph nodes as possible, because lymph node involvement is one of the most important prognostic indicators. Five groups of lymph nodes are included in a Whipple specimen3,4 and include: Antral-omental lymph nodes: lymph nodes of greater and lesser curvatures of the stomach. Superior pancreatic: lymph nodes localized be-
tween the pancreas and the pylorus and first portion of duodenum. Inferior pancreatic: lymph nodes localized between the inferior border pancreas and the duodenum. Pancreato-duodenal (anterior and posterior): lymph nodes between the head of the pancreas and second portion of duodenum. Common bile duct (portal): lymph nodes around the common bile duct, cystic duct. Gross Description It is important to have a standardized system for the pathologic evaluation of the pancreatoduodenectomy to avoid omissions in the gross description. A good way to organize the dictation is by paragraphs. In most gross descriptions you will have five paragraphs. The first paragraph describes the anatomic components of the specimen and describes the dimensions of each component. In the case of the pancreatoduodenectomy, you should record the dimension of the stomach (length of greater curvature, lesser curvature, circumference, and wall thickness), greater omentum (size in cms), duodenum (length and diameter), head of pancreas (three dimensions), and common bile duct (length and diameter). The pancreas should be described noting all anatomic landmarks. Note the condition of the uncinate process (if included) as the furrow that you will see is where the pancreas has been reflected from the adjacent portal vein. The second paragraph describes the main pathology. In the case of a tumor describe: (1) size, (2) site of origin, (3) tumor characteristics (color, consistency, fungating, flat, ulcerated, nonulcerated, presence of necrosis, hemorrhage, cyst formation), (4) margins (well defined, pushing, ill-defined), (5) distance from margins, and (6) obstruction of ducts or extension into duodenal wall. Some pancreatic tumors are difficult to identify because they only partially efface the normal lobular architecture of the pancreas. The best way to identify them is around a bile duct or pancreatic duct stricture. The third paragraph describes any additional pathology: fibrosis of pancreatic parenchyma or fat necrosis. Note that distal duodenal segment usually has a congested hyperemic appearance which is an artifact of the surgical procedure. This part of the gross description can also be used to describe normal pertinent information like the appearance of
The Pancreaticoduodenectomy
191
the ampulla of vater, the bile duct patency, or stent placement. The fourth paragraph describes the ink code (anterior, blue, posterior, black) and any other procedure like gross photography. The fifth paragraph describes the block summary, which is a detailed description of the tissue sections obtained and the way they were obtained (shave, perpendicular or radial sections). An example of the gross description of an ampullary tumor (Figs 5 and 6) will include: Received fresh in a single container and labeled with patient’s name, medical record number and “Whipple” is a pancreatoduodenectomy specimen that includes a portion of the distal stomach (10.0 cm in length ⫻ 9.0 cm in diameter ⫻ 0.5 cm wall thickness) with attached, unremarkable omentum (19.0 ⫻ 9.0 ⫻ 0.5 cms), first and second portions of duodenum (30.5 cm in length with average diameter of 3.5 cm.), head of pancreas and uncinate process (7.5 ⫻ 6.5 ⫻ 4.5 cm) and segment of markedly dilated common bile duct (4 cms in length ⫻ 3.2 cm in diameter). In the region of the ampulla there is a firm, tan-white, polypoid, partially ulcerated infiltrative mass that measures 3.2 ⫻ 2.2 ⫻ 2.0 cm (Fig 5). This mass is involving and completely obstructing the common bile duct at the ampulla and is partially obstructing the pancreatic duct (Fig 6). The tumor is localized at 3.5 and 3.0 cms from the surgical resection margin of the bile duct and the pancreas, respectively. The tumor invades the wall of the duodenum, but do not invade the head of the pancreas.
Figure 6. Ampullary carcinoma obstructing the distal portion of the bile duct and the pancreatic duct. (Same case of Fig 5).
The distal bile duct is markedly dilated, covered by an edematous and red mucosa. In the bile duct there is a white plastic stent. The pancreatic parenchyma is firm and lobulated. The gastric mucosa and wall are unremarkable. The distal duodenal mucosa is red and edematous. No other lesions are identified grossly. In the peripancreatic region multiple tan soft lymph nodes measuring from 0.5 to 2.0 cms are identified as follows: two in superior pancreatic region, one in the inferior pancreatic region, two in the pancreato-duodenal area (one anterior, one posterior) and one in the lesser curvature. The anterior pancreato-duodenal lymph node is markedly enlarged measuring 2.0 cm in greatest dimensions. Ink code: blue anterior, black posterior. A gross photograph is taken. Representative sections are submitted, see block summary.
Figure 7 shows another example of an ampullary tumor invading into the bile and pancreatic ducts. Notice the marked dilatation of the proximal common bile duct. Block Summary The standard tissue sections include:
Figure 5. Ampullary carcinoma forming a polypoid partially ulcerated mass in the lumen of the duodenum.
1. Shave section of proximal and distal margins (stomach and duodedum). 2. Shave section of bile duct margin (usually done at frozen section). 3. Shave section of pancreatic neck margin (usually done at frozen section).
192
Young and Castro
Diagnosis The pathology report should include all information that is required for the proper classification and stage of the tumors (TNM). Important issues to asses are:
Figure 7. Small, focally ulcerated ampullary carcinoma obstructing the common bile duct.
4. Perpendicular section of the uncinate margin taken to include the vascular groove. If the neoplasm is close to the uncinate margin, make sure that the section includes tumor. 5. Tumor: if less that 3 cms submit entirely. If larger, submit one per centimeter per tumor. Sections should include relationship of the tumor to pancreas, bile duct, pancreatic duct, ampulla, duodenal wall, and soft tissue margin. 6. Normal pancreas one of two cassettes. 7. Bile duct, random sections. 8. Duodenum, random section. 9. Ampulla of vater. Sections of the ampulla are a must. Lengthwise sections are best and should always include normal duodenal mucosa. 10. Soft tissue. Only the posterior soft tissue is a real margin (retroperitoneum).4 The remaining soft tissue sections are to evaluate extension of the tumor outside of the pancreas. The retroperitoneal margin is defined as the soft tissue margin along the right lateral border of the proximal 3 to 4 cms of the superior mesenteric artery. This important margin is often confused with the soft tissue posterior to the pancreatic head and duodenum. For proper identification, the retroperitoneal margin must be taken at the time of the surgery and sent for frozen section. Identification of this margin of resection is not possible once the gross examination of the specimen has been completed.4 11. Lymph nodes: all lymph nodes are submitted as separate groups.
1. Type of procedure and what structures or organs where present. 2. Tumor type and tumor grade. 3. Tumor location: What is the exact site of origin (pancreas, bile duct, ampulla of Vater, duodenum). Note: it may not be possible to determine the exact site of origin for large tumors, so a detail description of what areas are involved is indicated. 4. Tumor size (in centimeters). 5. Invasion: extension into the duodenum, ampulla of vater, common bile duct, cystic duct, peripancreatic soft tissues, retroperitoneal fat, mesentery, omentum, portal vein, etc. Note that according to the TNM classification in a case of a primary ampullary tumor, if there is pancreatic invasion present, the extent of invasion should be measured in centimeters, information need to separate tumor stage into a T3 or T4 lesions.2 6. Vascular, lymphatic, or perineural invasion. 7. Status of surgical resection margins (pancreatic neck margin, uncinate process margin, retroperitoneal margin, bile duct margin, duodenal and stomach margin). 8. Nodal status and site: Mention number of lymph nodes examined by area and the number of lymph nodes involved. Note that according to the TNM classification, the designation of regional versus distant lymph nodes (N1-3 versus M1) varies according to the primary site of the tumor. A group of lymph nodes that may be considered regional (N1 disease) for a cancer of the head of the pancreas, may be considered distant metastasis (M1) is the tumor is arising from the ampullary region.2 9. Additional pathology: chronic pancreatitis, fibrosis, islet cell hyperplasia, etc. Conclusion The pancreatoduodenectomy is a complex surgical procedure that involves multiple organ systems. A good preparation and careful dissection of the specimen is a must. The gross description should be detail and organized in such a manner that the
The Pancreaticoduodenectomy
reader can visualize in his mind the pathologic process and be able to easily extract the appropriate information to correctly stage the tumor. References 1. Whipple AO: The rationale of radical surgery for cancer of the pancreas and ampullary region. Ann Surg 1941;114:612-615 2. Ampullary of Vater and Exocrine pancreas, in Fleming ID, Cooper JS, Henson DE, et al (ed). AJCC Cancer Staging Manual.
193
Philadelphia, PA, Lippincott Williams & Wilkins,1997, pp 115126 3. Stanley CA, Cleary KR, Abbruzzese JL, et al: The need for standardized pathologic staging of pancreatoduodenectomy specimens. Pancreas1996;12:373-380 4. Evans DB, Abruzzese JL, Rich TA: Cancer of Pancreas, in DeVita VT, Hellman S, Rosenberg SA (eds). Cancer: Principles and Practice of Oncology. Philadelphia, PA, Lippincott –Raven, 1997, pp 1061-1063