Pancreatic Cancer Types Malignant

The majority of malignant pancreatic tumors originate in the epithelial tissue — the membrane of cells lining the ducts and tubes of the pancreas. Approximately 95 percent of pancreas cancers develop in this tissue.

Adenocarcinoma

Diagram/Illustration of Malignant Tumor

Adenocarcinomas are by far the most common type of pancreas cancer. Adenocarcinomas begin in the glandular ducts that manufacture pancreatic digestive juices, and are considered to be very aggressive neoplasms. Approximately 30,000 people are diagnosed with adenocarcinomas every year, and the yearly death toll is around 28,000.

Symptoms generally only develop once the disease is well advanced. It has often spread to other organs by the time a diagnosis is made. Surgical removal of the adenocarcinoma is possible in twenty to forty percent of cases. The five-year survival rate following surgical removal ranges from twenty to forty percent.

Other Types of Pancreatic Carcinoma

Less common forms of epithelial pancreas cancer include the following:

Acinar Carcinoma: A rare and highly aggressive form of adenocarcinoma that begins in the acinar cells. These cells produce digestive enzymes and a tumor here will often cause excessive production of digestive enzymes. Many patients will have metastases to the liver at the time of diagnosis.

Adenosquamous Carcinoma: A rare variation that is highly invasive and despite aggressive treatment almost uniformly has an extremely poor prognosis: few survive longer than one year following diagnosis.

Mucinous Cystadenocarcinoma: May develop from previously benign cystic growths and are characterized by fluid-filled sacs within the growth. They occur most often in women.

Pancreatoblastoma: A rare disease that affects children exclusively. Because this slow growing tumor is almost always surgically removable (“resectable”) and is responsive to both radiation and chemotherapy it has a comparatively high survival rate.

Mucous Ductal Ectasia: A slow growing tumor that begins in the lining of the pancreatic ducts, produces excessive amounts of mucus, and often results in chronic pancreatitis. Men over the age of sixty are in the highest risk group, and smoking increases the risk further.

Giant Cell Tumors: A rare form of adenocarcinoma, giant cell tumors are characterized by larger, “giant” cells. The tumor itself is less aggressive than other adenocarcinomas.

Perivascular Epitheliod Cell Tumors (PEComas): Also called clear cell or oncocytic carcinoma, PEComas are the most rare form of pancreatic adenocarcinoma and their malignant potential is uncertain.

Glossary of Terms

  • acinar: cells with microscopic cavities
  • adeno: gland (adenocarcinoma = cancerous glandular tumor)
  • blastoma: abnormal tissue growth originating from immature,undifferentiated cells
  • carcinoma: a neoplasm involving organ linings or skin
  • cyst: a fluid-filled sac
  • neoplasm: abnormal tissue growths
  • oma: a suffix indicating a tumor (such as adenocarcinoma)
  • squamous: flat cells lining hollow organs, and found on the skin surface.

Resources

Maisonneuve, P.