View large version
Embed image
Rare neoplasms: Mixed exocrine and endocrine neoplasms. Ductal adenocarcinomas and acinar cell carcinomas- also commonly contain a minor population of cells with neuroendocrine differentiation that is detected by immunostains. Other Neoplasms 1.Cystic Neoplasms 2.Sarcomas
Acinar, ductal or endocrine marker positive
Lipase hypersecretion
Ductal adenocarcinoma (90%) Comprised of mucous and signet cells, and may display a pattern consisting of glands, duct-like structures with papillary changes, or a cribriform pattern. Pathology: Dense stromal fibrosis due to TGF-b signalling alteration Therefore also called"scirrhous" or "desmoplastic" carcinomas. Epidemiology: Incidence and number of PanIN rise with age, Low grade PanIN (PanIN-1) 50% prevalence >50 yrs old PanIN progress to invasive cancer.
Normal ductal epithelium
Papillary lesion no atypia
(
PanIN-1)
Papillary lesion with atypia
PanIN-2
Invasive ductal adenocar
-
cinoma
PanIN-3
KRas/ SMAD4/p16
65% in head
10 to 15 % in tail
5 to 10 % in body
D u o d e n u m Pancreatic Intraepithelial Neoplasia = Small (generally <5 mm) intraductal noninvasive lesion that is formed by metaplasia and proliferation of ductal epithelium. The epithelium is columnar and contains increased cytoplasmic mucin. The majority appear to arise in smaller intralobular ducts but can appear anywhere. Colloid carcinomas (2 % of ductal carcinomas)- Composed of pools of mucous with clusters of malignant duct cells. Adenosquamous cancer s display areas of squamous differentiation; on occasion, the squamous component predominates. Less common variants include pleomor - phic carcinomas, sarcomatoid carcino - mas, and giant cell carcinomas Very rare : Medullary and signet ring carcinomas, hepatoid carcinoma, and benign neoplasms including teratoma and lymphoepithelial cyst. a) Ductal- 90% are all pancreatic cancers
Types
Acinar cell carcinoma -Rare malignant neoplasms that are usually solid, but are sometimes cystic. -Usually male adults- can occur anywhere in pancreas -Can cause lipase hypersecretion causing subcut fat necrosis ("pancreatic panniculitis"), and polyarthralgia- poor prognosis -Histologically, look like acinar cells, and contain zymogen granules -Overall prognosis better than for ductal adenocarcinoma. Pancreatoblastoma Solid malignant neoplasms of presumed stem cell origin. They appear to arise from primitive cells that have the potential to differentiate along several lines. Mainly occur in infants and children M=F and arise anywhere in pancreas 30% secrete aFP Histology: Composed of primitive small polygonal or spindle-shaped cells that is mixed with acinar, ductal or islet cells. Immunostaining can reveals acinar, ductal or endocrine markers among polygonal cells. Characteristic "squamoid" bodies are found among the primitive cells and provide a useful diagnostic feature. Less aggressive than ductal adenocarcinoma and have a higher cure rate after surgical resection. The prognosis is better in children than in adults. Local extension targets: The duodenum. The portal vein. The Superior mesenteric vessels. Perineural invasion. Occasionally there is local extension to the spleen, adrenal glands, vertebral column, transverse colon, and/or stomach. 3.Lymphomas
4.Endocrine neoplasms
5.
eg, mixed ductal-endocrine carcinoma, mixed acinar-endocrine carcinoma, and mixed acinar-endocrine- ductal carcinoma Probably from pluripotent cells but different from pancreaticoblastomas as no primitve component Wide resection margin difficult due to proximity of aorta, superior mesenteric artery, and portal vein so retroperitoneal tissue behind head of the pancreas is most common site of recurrence.
Pancreatic Cancer Pathology
Written by Dr Sebastian Zeki
