131. Pancreatic neoplasms. Tumors of the endocrine pancreas (islet cell tumors)

Question 1

Exocrine Tumors

Answer 1

1. cystic neoplasms
   serous cystadenomas
   mucinous cystic neoplasms
   intraductal papillary mucinous neoplasms
2. pancreatic adenocarcinoma

Question 2

Serous cystadenoma

Answer 2

benign
features: composed of glycogen rich cuboidal cell surrounding small cysts containing clear fluid
location: body or tail
risk group: older ppl
genetic: contain loss of function of VHL tumor supressor gene (negative regulator of HIF)
symptoms: abdominal pain
progression: mostly benign, resection cures them.

Question 3

Mucinous cystic neoplasms

Answer 3

features: slow growing mass, filled with mucin and lined by columnar epithelium with cellular stroma. Epithelium has various grades of dysplasia.
location: body or tail
risk groups: females
symptoms: painless
subtypes: low grade, moderate, and severe dysplasia
progression: one third can lead to invasive adenocarcinoma

Question 4

intraductal papillary mucinous neoplasms

Answer 4

features: no cellular stroma, epithelia have various grades of dysplasia
risk group: male
location: head, in the main pancreatic duct or one of its branches
genetic background: GNAS mutation
progression: might lead to adenocarcinoma, particularly colloid adenocarcinomas which are associated with abundant mucus production which is nearly always malignant transformation of this neoplasm

Question 5

pancreatic adenocarcinoma

Answer 5

origin: epithelial cells lining the pancreatic ducts
risk factors: smoking, obesity, old males
location: head or neck mostly
subtypes: acinar, adenosquamous, signet rink cell, undifferentiated
predisposing diseases: diabetes, chronic pancreatitis, liver cirrhosis
progression: PanIN 1A (kras point mutation) –> PanIN 1B-2 (p16 inactivated) –> PanIN 3 (p53, SMAD4, BRCA inactivated) –> invasive carcinoma
very poor prognosis
features: very invasive, desmoplastic rxn
complication:
- invasion to retroperitoneum
- jaundice (due to bile duct obstruction)
- Trosseau sign of malignancy: blood clots under skin
- courvoisier sign: gall bladder enalrged due to
obstruction of bile duct
- new onset of diabetes
symptoms:
- midepigastric pain, nausea, vomiting, fatigue, weight
loss
diagnostic: Ca 19-9, CEA
typically remain silent until their extension impinges on other structures

Question 6

Pancreatic Neuroendocrine Tumors

Answer 6

• Also known as islet cell tumors
• Account for only 2% of all pancreatic neoplasms
• Most common in adults
• If malignant, usually metastases to the liver
• Tumors have ability to produce pancreatic hormones, but some are non-functional
• All of these tumors have malignant potential besides insulinomas

1. insulinomas
2. gastrinomas

Question 7

insulinoma (beta cell tumors_

Answer 7

• Most common type
• Produce sufficient insulin to induce attacks of hypoglycemia when blood glucose levels fall below 50 mg/dL
• These attacks manifest as confusion, stupor, and loss of consciousness
• They are brought on by fasting or exercise, and are promptly relieved by feeding or parenteral administration of glucose
• Cured by surgical resection
• Morphology
o Small in size, most are solitary lesions
Deposition of amyloid is characteristic feature

Question 8

gastrinoma

Answer 8

• Hypersecretion of gastrin
• Can arise in pancreas, peripancreatic region, or wall of duodenum
• Zollinger-Ellison syndromeis a rare condition in which one or more tumors form in your pancreas or the upper part of your small intestine (duodenum). These tumors, called gastrinomas, secrete large amounts of the hormone gastrin, which causes your stomach to produce too much acid and form peptic ulcerations.
• Can arise in conjunction with other endocrine tumors, MEN-I syndrome.