Pancreas and extrahepatic bile duct

Question 1

Pancreas with haphazard, infiltrative growth of glands with within desmoplastic stroma showing cells with nuclear atypia. Perineural invasion and large ducts next to muscular vessels are unequivocal features.

Answer 1

Pancreatic ductal adenocarcinoma

Differential diagnosis:
Cholangiocarcinoma
Ampullary adenocarcinoma
Metastatic adenocarcinoma

Plan:
Correlate with clinical history, radiology (?lesion centred at ampulla or bile duct)
Examine further blocks (e.g. for total size, relation to margins, LVI/PNI)
IPX to support Dx: CK7, p53, SMAD4 (expect CK7 positive, p53 mutant, loss of SMAD4)
Next steps: Synoptic report, discuss at MDT

Question 2

Pancreas with fibrosis that mimics desmoplastic stroma, however on low power retains lobular architecture. Residual islets of Langerhans can appear infiltrative, but retain neuroendocrine morphology.

Answer 2

Chronic pancreatitis

Differential diagnosis:
IgG4 related pancreatitis
Pancreatic ductal adenocarcinoma

Plan:
Correlate with clinical history and radiology
Examine further blocks (e.g. for adenocarcinoma arising in context of chronic pancreatitis)
IPX to discount DDx: IgG / IgG4, p53, SMAD4 (expect normal IgG4 to IgG ratio in plasma cells, mosaic p53 staining, SMAD4 retained)

Question 3

Sponge like cystic lesion of pancreas, often with central scar. Cysts are lined by a single layer of cuboidal cells with clear cytoplasm, and small dark uniform round nuclei.

Answer 3

Serous cystadenoma

Differential diagnosis:
Metastatic clear cell RCC

Plan:
Correlate with clinical history and radiology (?patient with VHL syndrome)
Examine further blocks (e.g. for total size, relation to margins)
IPX to discount DDx: PAX8
Advice to clincian: Benign lesion, may be sporadic or assiociated with Von-Hippel-Lindau syndrome. Clinical correlation is required

Question 4

Nodule in gallbladder formed from cystically dilated benign biliary glands accompanied by smooth muscle hypertrophy of gallbladder wall

Answer 4

Adenomyomatous hyperplasia of gallbladder

Plan:
Correlate with clinical history and radiology (?history of cholelithiasis)
No specific action required for this benign diagnosis

Question 5

Well-circumscribed pancreatic neoplasm composed of solid sheets and pseudopapillae formed by discohesive, monotonous cells surrounding delicate fibrovascular stalks. The cells have round to oval nuclei, often with nuclear grooves, fine chromatin, inconspicuous nucleoli, and moderate amounts of eosinophilic or clear cytoplasm. Intracytoplasmic hyaline globules are characteristic. Degenerative changes, including hemorrhage, cholesterol clefts, and foamy macrophages, are common.

Answer 5

Solid pseudopapillary neoplasm (SPN) of pancreas

DDx:
Pancreatic neuroendocrine tumour
Pancreatic acinar adenocarcinoma

Plan:
Correlate with clinical history and radiology
Examine further blocks (e.g for total size, relation to margins)
Special stains to support Dx: PAS/DPAS (stain hyaline globules)
IPX to support Dx: CD10, beta catenin (expect nuclear positivity)
IPX to discount DDx: Synaptophysin and chromogranin, trypsin and chymotripsin
Next steps: Synoptic report, discuss at MDT

Question 6

Pancreas with multilocular cyst with cyst locules lined by epithelium resembling low grade PanIN, surrounded by ovarian-type stroma.

Answer 6

Mucinous cystic neoplasm (MCN) of pancreas with low grade dysplasia

Plan:
Correlate with clinical history and radiology (usually in tail/body, do not communicate with main duct system)
Examine further blocks (e.g. for size, relation to margins, and any areas of high grade dysplasia or invasive carcinoma)
IPX to support Dx: Inhibin, CD10, ER/PR stain ovarian type stroma
Next steps: Synoptic report, discuss at MDT