http://www.merck.com/mrkshared/mmanual/section3/chapter34/34e.jsp
Pancreatic Tumors

Exocrine tumors of the pancreas develop from ductal and acinar cells.
Endocrine tumors arise from islet and gastrin-producing cells and often
produce many hormones.
EXOCRINE TUMORS
Ductal Adenocarcinoma

Adenocarcinomas of the exocrine pancreas arise from duct cells nine times
more often than from acinar cells; 80% occur in the head of the gland.
Adenocarcinomas appear at the mean age of 55 yr and occur 1.5 to 2 times
more often in men.
Symptoms and Signs

Symptoms occur late in the course of disease; by diagnosis, 90% of patients
have tumor that is locally advanced and has directly involved
retroperitoneal structures, spread to regional lymph nodes, or metastasized
to the liver or lung. Weight loss and abdominal pain occur in most patients
with advanced disease. Adenocarcinomas may produce obstructive jaundice
and, if in the body and tail, splenic vein obstruction, splenomegaly,
gastric and esophageal varices, and GI hemorrhage. Most patients have
increasing severe upper abdominal pain, which usually radiates to the back.
Although pancreatic cancer pain may be relieved by bending forward or
assuming the fetal position, all patients eventually require narcotic
analgesics.

Prognosis and Treatment

Overall 5-yr survival is < 2%. If the tumor is localized to the head of the
pancreas (<= 2 cm), as occurs in only 10% of patients, a total
pancreatectomy or Whipple's operation (pancreaticoduodenectomy) results in
5-yr survival of 15 to 20%.

Cystadenocarcinoma

A rare adenomatous pancreatic cancer that arises as a malignant
degeneration of a mucous cystadenoma and presents as upper abdominal pain
and a palpable abdominal mass.

Ultrasound or CT of the pancreas shows cystadenocarcinoma as a cystic mass
with debris in it, but scans may be falsely interpreted as necrotic
adenocarcinoma or pancreatic pseudocyst. Unlike ductal adenocarcinoma,
cystadenocarcinoma has a relatively good prognosis. Only 20% of patients
have metastasis at the time of operation; complete excision of the tumor by
distal or total pancreatectomy or by Whipple's operation results in a 65%
5-yr survival.
Intraductal Papillary-Mucinous Tumor

A recently described syndrome of dilatation of the main pancreatic duct or
branch ducts, with mucin overproduction.

Episodic pain that appears to be pancreatic in origin and mucinous
(macrocystic) neoplasms (cystadenomas, cystadenocarcinomas) may occur in
association with intraductal papillary-mucinous tumors (IPMT). Of IPMT, >
30% are malignant at operation, but the natural history is unknown. The
appearance of the ducts on imaging often leads to a diagnosis of chronic
pancreatitis, but extrusion of mucus from the papilla or the presence of
filling defects (which correspond to globs of mucus) within the pancreatic
ducts at ERCP is almost pathognomonic of the condition. Because these
studies cannot distinguish invasive malignant disease, surgical excision of
the dysplastic area is the best treatment.
ENDOCRINE TUMORS

Pancreatic endocrine tumors have two general presentations. Nonfunctioning
tumors may cause obstructive symptoms of the biliary tract or duodenum,
bleeding into the GI tract, or abdominal masses. Functioning tumors
hypersecrete a particular hormone, causing various syndromes, including
hypoglycemia (insulinoma hypersecretes insulin); Zollinger-Ellison syndrome
(gastrinoma hypersecretes gastrin); vipoma (vasoactive intestinal peptide
or prostaglandins E and E2 hypersecretion); carcinoid syndrome (caused by
carcinoid tumors--see Ch. 17); diabetes (glucagonoma hypersecretes
glucagon); Cushing's syndrome (ACTH hypersecretion); and mild hyperglycemia
with cholelithiasis (somatostatinoma). These clinical syndromes also occur
sometimes in multiple endocrine neoplasia (see Ch. 10), in which tumors or
hyperplasia affects two or more endocrine glands, usually the parathyroid,
pituitary, thyroid, or adrenals.
Insulinoma

A rare islet cell tumor that hypersecretes insulin.

Insulinoma is a tumor of pancreatic beta cells or, rarely, diffusely
hyperplastic beta cells. Of all insulinomas, 80% are single and may be
curatively resected if identified. Only 10% of insulinomas are malignant.
It occurs in 1/250,000 persons at a median age of 50 yr, except in multiple
endocrine neoplasia type I (about 10% of insulinomas), when it occurs in
the third decade of life. Insulinomas associated with multiple endocrine
neoplasia type I are more likely to be multiple.

Overall surgical cure rates should approach 90%. A small, single insulinoma
at or near the surface of the pancreas can usually be enucleated
surgically. If a single large or deep adenoma is within the pancreatic body
or tail, if there are multiple lesions of the body or tail (or both), or if
no insulinoma is found (an unusual circumstance), a distal, subtotal
pancreatectomy is performed. In < 1% of cases, the insulinoma is
ectopically located in peripancreatic sites of the duodenal wall or
periduodenal area and can be found only by diligent search.
Pancreaticoduodenectomy (Whipple's operation) is performed for resectable
malignant insulinomas of the proximal pancreas. Total pancreatectomy is
performed if a previous subtotal pancreatectomy proves inadequate.

If hypoglycemia continues, oral diazoxide (3 to 8 mg/kg in two to three
equal doses q 8 to 12 h) in conjunction with a natriuretic can be used. The
appropriate starting dose is 3 mg/kg; subsequent doses can be adjusted
according to need. The combination of streptozocin (1 g/m2 BSA IV weekly
for 4 wk) and 5-FU benefits 50% of patients but requires monitoring of
renal function (urine proteins, serum creatinine), hepatic function, and
cell counts (potential hematopoietic toxicity) and does not improve
survival. A long-acting somatostatin analog, octreotide (100 to 500 µg sc
bid to tid), is variably effective and should be considered to treat
symptomatic insulinoma patients with continuing hypoglycemia who are
refractory to diazoxide.
Zollinger-Ellison Syndrome
(Z-E Syndrome; Gastrinoma)

A syndrome characterized by marked hypergastrinemia, gastric
hypersecretion, and peptic ulceration caused by a gastrin-producing tumor
of the pancreas or the duodenal wall.

Vipoma

A tumor of non-beta pancreatic islet cells causing a syndrome of watery
diarrhea, hypokalemia, and achlorhydria.
Symptoms and Signs

Of these tumors, 50 to 75% are malignant, and some may be quite large (7
cm) at diagnosis. They may be identified within the pancreas by
immunocytochemistry. Vipoma syndrome may occur as part of multiple
endocrine neoplasia (see Ch. 10). The major clinical features are prolonged
massive watery diarrhea (fasting stool volume > 750 to 1000 mL/day and
nonfasting volumes of > 3000 mL/day) and symptoms of hypokalemia, acidosis,
and dehydration. Of patients, 50% have relatively constant diarrhea,
whereas the rest have alternating severe and moderate diarrhea; 33% have
diarrhea < 1 yr before diagnosis, but 25% have diarrhea >= 5 yr before
diagnosis. Lethargy, muscular weakness, nausea, vomiting, and crampy
abdominal pain are frequent. Hyperglycemia and impaired glucose tolerance
occur in <= 50% of patients. Rarely, flushing similar to the carcinoid
syndrome occurs during attacks of diarrhea.

Tumor resection is curative in 50% of patients with a localized tumor. In
those with metastatic tumor, resection of all visible tumor may provide
temporary relief of symptoms. The combination of streptozocin and
doxorubicin may reduce diarrhea and tumor mass if objective response occurs
(in 50 to 60%). Chemotherapy is not curative.
Glucagonoma

Pancreatic alpha-cell glucagon-secreting tumors that produce hyperglycemia.

Glucagonomas are very rare but similar to other islet cell tumors in that
the primary and metastatic lesions are slow-growing: 15-yr survival is
common. Of glucagonomas, 80% are malignant. The average age at symptom
onset is 50 yr; 80% of patients are women

etc...
J

thank you barbara - the info is appreciated