Somatostatinoma is a tumor of the delta cell

Delta cell

Delta cells are somatostatin-producing cells.They can be found in the stomach, intestine and the Islets of Langerhans in the pancreas....

s of the endocrine pancreas that produces somatostatin

Somatostatin

Somatostatin is a peptide hormone that regulates the endocrine system and affects neurotransmission and cell proliferation via interaction with G-protein-coupled somatostatin receptors and inhibition of the release of numerous secondary hormones.Somatostatin...

.

It is associated with diabetes mellitus

Diabetes mellitus

Diabetes mellitus, often simply referred to as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced...

 and abnormal glucose tolerance.

Triad of : Mild Diabetes mellitus

Diabetes mellitus

Diabetes mellitus, often simply referred to as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced...

, Steatorrhoea, Gall stones. also associated with hypochlorhydria.

Commonly found in head of pancreas

Head of pancreas

The head of pancreas is a portion of the pancreas that is lodged within the curve of the duodenum, and is flattened anteriorly . The other parts of the pancreas are the body and the tail....

, and are malignant.

Elevated plasma levels of Somatostatin.

Pathophysiology

in a normal subject actions of Somatostatin

Somatostatin

Somatostatin is a peptide hormone that regulates the endocrine system and affects neurotransmission and cell proliferation via interaction with G-protein-coupled somatostatin receptors and inhibition of the release of numerous secondary hormones.Somatostatin...

 include:

In the anterior pituitary gland, the effects of somatostatin are:

• Inhibit the release of growth hormone
  Growth hormone
  Growth hormone is a peptide hormone that stimulates growth, cell reproduction and regeneration in humans and other animals. Growth hormone is a 191-amino acid, single-chain polypeptide that is synthesized, stored, and secreted by the somatotroph cells within the lateral wings of the anterior...
  
   thus opposing the effects of Growth Hormone-Releasing Hormone (GHRH)
• Inhibit the release of thyroid-stimulating hormone
  Thyroid-stimulating hormone
  Thyrotrophin-stimulating hormone is a peptide hormone synthesized and secreted by thyrotrope cells in the anterior pituitary gland, which regulates the endocrine function of the thyroid gland.- Physiology :...
  
   (TSH)
  • Somatostatin suppresses the release of gastrointestinal hormone
    Gastrointestinal hormone
    The gastrointestinal hormones constitute a group of hormones secreted by enteroendocrine cells in the stomach, pancreas, and small intestine that control various functions of the digestive organs...
    
    s
  • Gastrin
    Gastrin
    In humans, gastrin is a peptide hormone that stimulates secretion of gastric acid by the parietal cells of the stomach and aids in gastric motility. It is released by G cells in the antrum of the stomach, duodenum, and the pancreas...
    
    
  • Cholecystokinin
    Cholecystokinin
    Cholecystokinin is a peptide hormone of the gastrointestinal system responsible for stimulating the digestion of fat and protein...
    
     (CCK)
  • Secretin
    Secretin
    Secretin is a hormone that controls the secretions into the duodenum, and also separately, water homeostasis throughout the body. It is produced in the S cells of the duodenum in the crypts of Lieberkühn...
    
    
  • Motilin
    Motilin
    Motilin is a 22-amino acid polypeptide hormone in the motilin family that, in humans, is encoded by the MLN gene.Motilin is secreted by endocrine M cells that are numerous in crypts of the small intestine, especially in the duodenum and jejunum. Based on amino acid sequence, motilin is unrelated...
    
    
  • Vasoactive intestinal peptide
    Vasoactive intestinal peptide
    Vasoactive intestinal peptide also known as the vasoactive intestinal polypeptide or VIP is a peptide hormone containing 29 amino acid residues that is produced in many tissues of vertebrates including the gut, pancreas and suprachiasmatic nuclei of the hypothalamus in the brain...
    
     (VIP)
  • Gastric inhibitory polypeptide (GIP)
  • Enteroglucagon
    Enteroglucagon
    Enteroglucagon is a peptide hormone derived from preproglucagon. It is a gastrointestinal hormone, secreted from mucosal cells primarily of the colon and terminal ileum. It has 37 amino acids. Enteroglucagon is released following ingestion of a mixed meal, and delays gastric emptying.- External...
    
    
    • Lowers the rate of gastric emptying, and reduces smooth muscle contractions and blood flow within the intestine
    • Suppresses the release of pancreatic hormones
  • Inhibits the release of insulin
    Insulin
    Insulin is a hormone central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle....
    
    
  • Inhibits the release of glucagon
    Glucagon
    Glucagon, a hormone secreted by the pancreas, raises blood glucose levels. Its effect is opposite that of insulin, which lowers blood glucose levels. The pancreas releases glucagon when blood sugar levels fall too low. Glucagon causes the liver to convert stored glycogen into glucose, which is...
    
    
    • Suppresses the exocrine secretory action of pancreas
      Pancreas
      The pancreas is a gland organ in the digestive and endocrine system of vertebrates. It is both an endocrine gland producing several important hormones, including insulin, glucagon, and somatostatin, as well as a digestive organ, secreting pancreatic juice containing digestive enzymes that assist...
      
      .

This explaining how abnormally elevatedSomatostatin

Somatostatin

Somatostatin is a peptide hormone that regulates the endocrine system and affects neurotransmission and cell proliferation via interaction with G-protein-coupled somatostatin receptors and inhibition of the release of numerous secondary hormones.Somatostatin...

 can cause Diabetes mellitus

Diabetes mellitus

Diabetes mellitus, often simply referred to as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced...

, by inhibiting insulin

Insulin

Insulin is a hormone central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle....

 secretion, Steatorrhoea by inhibiting Cholecystokinin

Cholecystokinin

Cholecystokinin is a peptide hormone of the gastrointestinal system responsible for stimulating the digestion of fat and protein...

 and Secretin

Secretin

Secretin is a hormone that controls the secretions into the duodenum, and also separately, water homeostasis throughout the body. It is produced in the S cells of the duodenum in the crypts of Lieberkühn...

, Gall stones by inhibiting Cholecystokinin

Cholecystokinin

Cholecystokinin is a peptide hormone of the gastrointestinal system responsible for stimulating the digestion of fat and protein...

 which normally induce gallbladder

Gallbladder

In vertebrates the gallbladder is a small organ that aids mainly in fat digestion and concentrates bile produced by the liver. In humans the loss of the gallbladder is usually easily tolerated....

 myocytes contraction, and hypochlorhydria caused by inhibiting Gastrin

Gastrin

In humans, gastrin is a peptide hormone that stimulates secretion of gastric acid by the parietal cells of the stomach and aids in gastric motility. It is released by G cells in the antrum of the stomach, duodenum, and the pancreas...

, which normally stimulate acid secretion.

Treatment

Treatment is by chemotherapy

Chemotherapy

Chemotherapy is the treatment of cancer with an antineoplastic drug or with a combination of such drugs into a standardized treatment regimen....

 with streptozocin, dacarbazine

Dacarbazine

Dacarbazine is an antineoplastic chemotherapy drug used in the treatment of various cancers, among them malignant melanoma, Hodgkin lymphoma, sarcoma, and islet cell carcinoma of the pancreas.Dacarbazine is a member of the class of alkylating agents, which destroy cancer cells by adding an alkyl...

, doxorubicin

Doxorubicin

Doxorubicin INN is a drug used in cancer chemotherapy. It is an anthracycline antibiotic, closely related to the natural product daunomycin, and like all anthracyclines, it works by intercalating DNA....

.

See also

• Gastrin
  Gastrin
  In humans, gastrin is a peptide hormone that stimulates secretion of gastric acid by the parietal cells of the stomach and aids in gastric motility. It is released by G cells in the antrum of the stomach, duodenum, and the pancreas...
  
  
• Cholecystokinin
  Cholecystokinin
  Cholecystokinin is a peptide hormone of the gastrointestinal system responsible for stimulating the digestion of fat and protein...
  
   (CCK)
• Secretin
  Secretin
  Secretin is a hormone that controls the secretions into the duodenum, and also separately, water homeostasis throughout the body. It is produced in the S cells of the duodenum in the crypts of Lieberkühn...
  
  
• Motilin
  Motilin
  Motilin is a 22-amino acid polypeptide hormone in the motilin family that, in humans, is encoded by the MLN gene.Motilin is secreted by endocrine M cells that are numerous in crypts of the small intestine, especially in the duodenum and jejunum. Based on amino acid sequence, motilin is unrelated...
  
  
• Vasoactive intestinal peptide
  Vasoactive intestinal peptide
  Vasoactive intestinal peptide also known as the vasoactive intestinal polypeptide or VIP is a peptide hormone containing 29 amino acid residues that is produced in many tissues of vertebrates including the gut, pancreas and suprachiasmatic nuclei of the hypothalamus in the brain...
  
   (VIP)
• Gastric inhibitory polypeptide (GIP)
• Enteroglucagon
  Enteroglucagon
  Enteroglucagon is a peptide hormone derived from preproglucagon. It is a gastrointestinal hormone, secreted from mucosal cells primarily of the colon and terminal ileum. It has 37 amino acids. Enteroglucagon is released following ingestion of a mixed meal, and delays gastric emptying.- External...
  
  
• insulin
  Insulin
  Insulin is a hormone central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle....
  
  
• glucagon
  Glucagon
  Glucagon, a hormone secreted by the pancreas, raises blood glucose levels. Its effect is opposite that of insulin, which lowers blood glucose levels. The pancreas releases glucagon when blood sugar levels fall too low. Glucagon causes the liver to convert stored glycogen into glucose, which is...
  
  
• Somatostatin
  Somatostatin
  Somatostatin is a peptide hormone that regulates the endocrine system and affects neurotransmission and cell proliferation via interaction with G-protein-coupled somatostatin receptors and inhibition of the release of numerous secondary hormones.Somatostatin...
  
  
• Diabetes mellitus
  Diabetes mellitus
  Diabetes mellitus, often simply referred to as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced...