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, 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