Pancreas Flashcards
Chronic pancreatitis: Associations with pancreatic cancer.
Either one can cause the other; either one can mimic the other.
Chronic pancreatitis: Gross-pathology clues to alcoholic origin (2).
Pseudocyst.
Intraductal calculi.
Chronic pancreatitis: Possible confounding effects on islets of Langerhans (2).
Aggregations of islets may mimic neoplasm.
Islets may abut nerves.
Chronic pancreatitis: Helpful signs of benignity (2).
Preservation of lobular architecture.
No glands adjacent to muscular blood vessels.
Genes that predispose to chronic pancreatitis:
A. Names (2).
B. Other implications (2).
A. PRSS1, SPINK1.
B. Acute pancreatitis in childhood; pancreatic cancer.
Autoimmune pancreatitis: Histology (3).
Duct-centered lymphoplasmacytic infiltrate.
Interstitial fibrosis.
Venulitis.
Autoimmune pancreatitis: Treatment.
May respond to steroids.
Pancreatic pseudocyst: Outcomes (3).
Spontaneous resolution.
Infection.
Erosion into adjacent organs.
Pancreatic pseudocyst: Cytology (2).
Necrotic and hemorrhagic debris.
Hemosiderin-laden macrophages.
Pancreatic pseudocyst: Laboratory findings in cyst fluid.
Elevated amylase and CA19-9.
Lymphoepithelial cyst: Epidemiology.
M : F = 4 : 1.
Lymphoepithelial cyst: Gross pathology.
Thin wall; keratinous contents.
Lymphoepithelial cyst: Histopathology (2).
Lining composed of keratinized squamous epithelium.
Underlying lymphoid tissue.
Lymphoepithelial cyst: Main differential diagnosis.
Mature cystic teratoma also contains adnexal structures and sometimes cartilage.
Lymphoepithelial cyst: Clinical associations.
None demonstrated.
Serous cystic neoplasm: Epidemiology.
More common in women.
Serous cystic neoplasm: Association.
Von Hippel-Lindau syndrome.
Serous cystic neoplasm: Variants in gross pathology (4).
Microcystic.
Macrocystic.
Solid.
Association with well-differentiation neuroendocrine tumor.
Serous cystic neoplasm: Histopathology (3).
Lined by bland cells analogous to normal pancreatic serous cells.
Solid variant consists of the same type of cell.
Central scar (may be seen radiologically).
Serous cystic neoplasm: Special stain.
Positive for PAS, sensitive to diastase (contain glycogen).
Serous cystic neoplasm: Mutation.
Some tumors have a mutation involving VHL on chromosome 3p.
Serous cystic neoplasm: How to distinguish benign from malignant.
Serous cystadenocarcinoma: Extremely rare; diagnosed by its spread to other organs.
Mucinous cystic neoplasms: Epidemiology.
F : M = 20 : 1.
Mucinous cystic neoplasms: How many are malignant?
About one third.
Mucinous cystic neoplasms: Anatomic location (2).
Body or tail of pancreas.
No connection with the ductal system.
Mucinous cystic neoplasms: Histopathologic classification (4).
Noninvasive:
− Low-grade dysplasia.
− Intermediate-grade dysplasia.
− High-grade dysplasia.
Invasive: Cystadenocarcinoma.
Mucinous cystic neoplasm:
A. Stroma.
B. Cytokeratins (2).
A. Ovarian-like.
B. CK7 in most, CK20 in about ⅔.
Mucinous cystic neoplasms: Important gene.
Smad4/DPC4:
− Unmutated in most noninvasive tumors.
− Lost in about half of invasive tumors.
Mucinous cystic neoplasm: Other possibly mutated genes (3).
RNF43, KRAS2, TP53.
Intraductal papillary mucinous neoplasm: Epidemiology.
Slightly more common in men.
Intraductal papillary mucinous neoplasm: How many are invasive?
About one third.
Autoimmune pancreatitis: Helpful stains (2).
IHC for IgG4.
Elastin stain or Movat’s stain to demonstrate venulitis.
Intraductal papillary mucinous neoplasm: Histopathologic classification.
Same as that of mucinous cystic neoplasm.
Intraductal papillary mucinous neoplasm: Stroma.
Paucicellular.
Intraductal papillary mucinous neoplasm: Invasive types (2).
Tubular (ductal).
Colloid (mucinous non-cystic): At least 80% of the tumor must have mucinous histology.
Intraductal papillary mucinous neoplasm: Immunohistochemstry.
Intestinal type: MUC2.
Pancreaticobiliary type: MUC1.
Intraductal papillary mucinous neoplasm: Possibly mutated genes (5).
Smad4/DPC4.
RNF43, KRAS2, TP53, GNAS.
Intraductal papillary mucinous neoplasm: Favorable prognostic factors (2).
Overall: Absence of invasion.
Invasive tumors: Colloid histology.
Pancreatic intraepithelial neoplasia: Size.
Usually less than 0.5 cm.
Pancreatic intraepithelial neoplasia: Histopathology (2).
Occurs within smaller pancreatic ducts.
If there are papillae, these are shorter than those of a mucinous papillary neoplasm.
Pancreatic intraepithelial neoplasia: Associated histopathologic finding.
Lobular acinar units may show atrophy and scarring.
Pancreatic intraepithelial neoplasia: Immunohistochemistry.
Positive for MUC1.
Pancreatic intraepithelial neoplasia: Mutated genes.
PanIN-1: Activation of KRAS2.
PanIN-2: Inactivation of p16/CDKN2A.
PanIN-3: Loss of Smad4/DPC4 and of TP53.
Pancreatic intraepithelial neoplasia: Surgical significance.
The presence of PanIN at a margin usually does not matter.
Invasive ductal adenocarcinoma: Gross-pathology clue to the diagnosis.
“Double-duct” sign: Dilatation of main pancreatic duct and bile duct due to obstruction.
Histology of invasive ductal adenocarcinoma: Architectural clues to the diagnosis (5).
Loss of lobular architecture.
Glands immediately adjacent to muscular blood vessels.
Incomplete lumens.
Necrotic lumens.
Perineural or vascular invasion.
Histology of invasive ductal adenocarcinoma: Cytologic clue to the diagnosis.
Within a single gland, there is more than a fourfold variation in size of the nuclei.
Adenosquamous carcinoma: Definition.
At least 30% of the tumor is squamous.
Colloid carcinoma:
A. Definition.
B. Association.
A. At least 80% of the tumor has colloid histology.
B. Intraductal papillary mucinous neoplasm (almost always).
Medullary carcinoma: Histopathology (3).
Syncytial growth.
Pushing borders.
Lymphocytic infiltrate.
Medullary carcinoma: Mutation.
Microsatellite instability.
Signet-ring carcinoma:
A. Stain.
B. Differential diagnosis.
A. Loss of E-cadherin.
B. Signet-ring carcinomas of stomach and breast must be excluded.
Undifferentiated carcinoma, NOS: Histologic variants (3).
Anaplastic, sarcomatoid, carcinosarcoma.
Undifferentiated carcinoma with osteoclast-like giant cells: Histopathology.
Osteoclast-like giant cells accompanied by pleomorphic mononuclear cells.
Pancreatic cancer: Associated cancer-syndrome genes (4).
BRCA2 and PALB2.
STK11.
ATM.
Intraductal papillary mucinous neoplasm: Anatomic location (2).
Most tumors arise in the head of the pancreas.
Connection with the ductal system.
Autoimmune pancreatitis: Laboratory finding.
Elevated serum IgG4.
Autoimmune pancreatitis: Associated autoimmune diseases (5).
Chronic sclerosis sialadenitis.
PSC, inflammatory bowel disease.
Retroperitoneal fibrosis.
Riedel’s thyroiditis.
Acinar-cell carcinoma: Epidemiology.
More common in males.
Clinical triad of acinar-cell carcinoma:
A. Frequency.
B. Components.
C. Cause.
A. Occurs at presentation in 15% of cases.
B. Metastatic fat necrosis, arthralgias, peripheral eosinophilia.
C. Lipase.
Acinar-cell carcinoma: Anatomic location.
Head or tail or pancreas.
Acinar-cell carcinoma: Histologic patterns (2).
Acinar or solid.
Acinar-cell carcinoma: Cytology.
Granular cytoplasm; basally oriented nucleus with a single large nucleolus.
Acinar-cell carcinoma: Variant.
Partial neuroendocrine differentiation.
Acinar-cell carcinoma: Mutation.
KRAS2 is rarely implicated.
Pancreatoblastoma: Associated syndromes (2).
Beckwith-Wiedemann.
FAP.
Pancreatoblastoma: Laboratory abnormality.
Elevated AFP in some cases.
Pancreatoblastoma: Anatomic location.
Head or tail of pancreas.
Pancreatoblastoma: Components (2,3).
Required: Acinar and squamoid.
Optional: Neuroendocrine, ductal, mesenchymal.
Pancreatoblastoma: Immunohistochemistry (4).
Acinar cells: Trypsin, antichymotrypsin, lipase.
Squamoid nests: Nonspecific labeling with biotin.
Pancreatoblastoma: Mutation.
Loss of heterozygosity at chromosome 11p near WT-2.
Well-differentiated pancreatic neuroendocrine tumors: Possibly associated gene and its location.
MEN1 on chromosome 11q13.
Well-differentiated pancreatic neuroendocrine tumors: Definition of microadenoma.
Less than 0.5 cm.
Well-differentiated pancreatic neuroendocrine tumors: Important histologic prognostic factor.
Mitotic rate.
Glucagonoma: Presentation (3).
Diabetes.
Necrotizing migratory erythema.
Stomatitis.
Gastrinoma: Presentation.
Duodenal ulcer.
VIPoma: Presentation (3).
Watery diarrhea.
Achlorhydria.
Hypokalemia.
Well-differentiated pancreatic neuroendocrine tumors: Histological clues to type of hormone.
Presence of amyloid may indicate an insulinoma.
Presence of psammoma bodies may indicate a somatostatinoma.
Well-differentiated pancreatic neuroendocrine tumors: Special stains (2).
Grimelius.
Fontana-Masson.
Well-differentiated pancreatic neuroendocrine tumors: Cytokeratin.
Usually negative for CK7, unlike pancreatic ductal adenocarcinoma.
Well-differentiated pancreatic neuroendocrine tumors: Relation of size to malignancy.
All tumors larger than 0.5 cm should be considered malignant.
High-grade neuroendocrine carcinoma:
A. Synonym.
B. Possible presentation.
A. Small-cell carcinoma.
B. Paraneoplastic syndrome such as Cushing’s syndrome.
High-grade neuroendocrine carcinoma: Mitotic rate.
More than 20 per 10 high-power fields (by definition).
High-grade neuroendocrine carcinoma: Mutated genes (2).
RB, TP53.
Solid-pseudopapillary neoplasm: Anatomic location.
Can arise from any region of the pancreas.
Solid-pseudopapillary neoplasm: Cytology.
Nuclear grooves.
Solid-pseudopapillary neoplasm: Extracellular features (2).
Hyaline globules.
Cholesterol clefts.
Solid-pseudopapillary neoplasm: Immunohistochemistry (2).
Positive for CD10, (nuclear) β-catenin.
Solid-pseudopapillary neoplasm: Mutation.
β-Catenin.
