Chapter 10 - Pancreas Flashcards
What are the five margins of the Whipple?
Pancreatic neck
Uncinate
Common bile duct
Proximal duodenum (or stomach)
Distal duodenum
Describe the normal morphology of the exocrine and endocrine pancreas.
Exocrine: Acinar cells (wedge-shaped pink & purple granular cells) draining into ducts (low cuboidal epithelium).
Endocrine: Scattered nests of neuroendocrine cells (Islets of Langerhans)
Describe some features that can distinguish pancreatic adenocarcinoma from chronic pancreatitis.
Random, irregular distribution of glands (vs lobular architecture)
Incomplete lumina and luminal necrosis
More pronounced cellular pleomorphism (4:1)
Invasion of nerve, muscular vessels, or duodenum
Describe the morphologic appearance of PanIN1A/B
Flat layer of tall columnar cells with basal nuclei, apical mucin, and no atypia. PanIN1B has papillary or undulating appearance.
Describe the morphologic appearance of PanIN2.
Flat or papillary but with some nuclear atypia. Resembles a tubular adenoma or low-grade dysplasia.
Describe the morphologic appearance of PanIN3.
Carcinoma in situ; with cribriforming, papillary, or micropapillary architecture. Necrosis and pronounced atypia.
What is the significance of PanIN1/2 on a margin?
None; they can be safely called negative.
What is an IPMN? How can it be distinguished from its primary differential diagnosis?
A mucin-producing neoplasm arising from a pancreatic duct. Distinguished from mucinous cystic neoplasm by communication with the duct system.
How are IPMNs graded?
With low / moderate / high-grade dysplasia
(These follow PanIN1/2/3, roughly)
What features favor an IPMN over a large duct PanIN?
Long papillae
Blue mucin in the duct lumen
Continuity with main ducts
Gross or radiologic visibility
Name some variants of pancreatic ductal adenocarcinoma.
Adenosquamous
Colloid (mucinous)
Hepatoid
Medullary
Signet ring cell
Undifferentiated (Anaplastic)
Undifferentiated with osteoclast-like giant cells
Where and in whom do mucinous cystic neoplasms occur?
Middle-aged women
Tail of pancreas
Describe the morphologic appearance of a mucinous cystic neoplasm.
Multilocular cysts (non-communicating) with a rim of ovarian stroma
How are mucinous cystic neoplasms graded?
With low / moderate / high-grade dysplasia
Follows PanIN 1 / 2 / 3, roughly.
Describe the morphologic appearance of pancreatic serous cystadenomas.
Microcystic (unlike ovarian), with a central scar and radiating microcysts lined by cuboidal mucinous cells.
Areas of solid or trabecular growth can mimic metastatic RCC.
What is a solid pseudopapillary neoplasm? Who do they affect?
A lesion that starts solid but undergoes cystic degeneration.
Occurs in young women.
Describe the morphologic appearance of a solid pseudopapillary neoplasm.
What stains are useful?
Noncohesive cells with a pseudopapillary growth pattern.
CD10+, nuclear beta-catenin.
Describe the morphologic appearance and location of pancreatic pseudocysts.
Granulation tissue and fat necrosis with no epithelial lining. These are usually extrapancreatic.
Describe the morphologic appearance of acinar cell carcinoma.
Nodules and sheets of densely packed amphophilic cells with uniform round nuclei. Prominent nucleoli!
Who do acinar cell carcinomas usually affect?
What stain can help identify them?
Older adults, usually male.
Trypsin
Describe the morphologic appearance of well-differentiated pancreatic endocrine neoplasm.
Well-circumscribed and cellular tumor with nests or trabeculae. Carcinoid cytology.
What are well-diff pancreatic endocrine neoplasms also called?
What do they stain?
Islet cell tumors
Synaptophysin/chromogranin, CD56, and any functional peptides
Normal pancreas
Arrow: Acini
Arrowhead: Duct
Left: Chronic pancreatitis
Arrow: Lobular ducts and acini
Right: Invasive adenocarcinoma
1: Large, prominent, irregular ducts
2: Ducts next to vessel
3: Ducts next to nerve
Adenocarcinoma
Arrow: Incomplete lumen
Arrowhead: Cribriforming
N: Perineural invasion
Inset: Marked pleomorphism
Chronic pancreatitis with residual islets of langerhans (arrowheads)
Pancreatic adenocarcinoma next to a vessel
A: PanIN 1
B: PanIN 2
C: PanIN 3
IPMN with moderate dysplasia and papillary projections.
Mucinous cystic neoplasm with underlying ovarina stroma (arrow)
Serous cystadenoma
Arrow: Small, dense nuclei with clear cytoplasm lining the cyst
Solid pseudopapillary tumor
Arrow: Fibrovascular cores with dropout of cells
Islet cell tumor
Note well spaced nuclei with speckled chromatin