Somatostatinomas are tumors originally generated from pancreatic or gastrointestinal tract cells and are expected to produce considerable symptomatology in the majority of the patients. Depending on the specific clinical presentation, somatostatinomas can be classified under two distinguishable categories: secretory, causing the inhibitory syndrome, and non-secretory ones, that remain asymptomatic and may be diagnosed incidentally or lead to enteric obstruction.

Those suffering from tumors that secrete somatostatin initially present with the aforementioned inhibitory syndrome. This entails a multitude of reported symptoms, such as diabetes mellitus that can be exacerbated even to a state of hyperglycemic ketoacidosis, cholelithiasis, and weight loss. Steatorrhea or diarrhea episodes are common and individuals tend to report up to ten foul-smelling stools per day; achlorhydria or hypochlorhydria is a frequent finding but does not usually lead to any remarkable complaint. Hormone-secretory somatostatinomas are primarily found in the pancreas; if they originate from the gastrointestinal tract (GIT), they are mainly large lesions, more than 4 cm [1]. Anorexia, vomiting and abdominal discomfort may co-exist.

With regard to non-secretory, or non-functional, somatostatinomas, they usually arise from the duodenum and manifest with duodenal obstruction, cholelithiasis, abdominal pain, jaundice of obstructive nature and bleeding of the GIT [2]. As a rule, they constitute tumors of a smaller diameter than their secretory counterparts and can even be asymptomatic. At the time of diagnosis, approximately 70% of these lesions will have metastasized to the regional lymph nodes or will have lead to hepatic metastases [3].

Some cases may come with symptoms that do not clearly classify them into one of the two previously mentioned categories; these include a wide variety of manifestations associated with pancreatic cancer and the syndrome is therefore described as mixed.

Some individuals with a somatostatinoma may also exhibit skin lesions characteristic of neurofibromatosis type 1 and symptoms further suggestive of a phaeochromocytoma, as these three medical entities are often concurrent [4] [5] [6].

• Weight Loss

  Other symptoms may include dyspepsia, weight loss, anemia, and hypochlorhydria. [autopsyandcasereports.org]

  Most SSomas present with non-specific symptoms of abdominal pain, weight loss, painless obstructive jaundice and diarrhea. [orpha.net]

  She had weight loss with hepatomegaly and ultrasonography indicated a pancreatic tumour which was shown to be a somatostatinoma. Resection resulted in prolonged survival. [ncbi.nlm.nih.gov]

• Anemia

  She exhibited features of somatostatinoma "inhibitory syndrome" characterized by mild nonketotic hyperglycemia, hypochlorhydria, cholelithiasis, steatorrhea, anemia, and weight loss. [ncbi.nlm.nih.gov]

  She exhibited features of somatostatinoma “inhibitory syndrome” characterized by mild nonketotic hyperglycemia, hypochlorhydria, cholelithiasis, steatorrhea, anemia, and weight loss. [journals.aace.com]

  Other symptoms may include dyspepsia, weight loss, anemia, and hypochlorhydria. [autopsyandcasereports.org]

  But it may present with diabetes, diarrhea, cholelithiasis, steatorrhea, indigestion, hypochlorhydria, and anemia. In contrast with pancreatic somatostatinoma, duodenal somatostatinoma, in general, is clinically silent. [jpatholtm.org]

• Surgical Procedure

  The majority of the patients underwent radical surgical procedures (Whipple procedure or pancreatic resection). [ncbi.nlm.nih.gov]

  The procedure may just involve the removal of a localized tumor. If the tumor has spread, it may require a more extensive surgical procedure known as a Whipple procedure. [medicalnewstoday.com]

  In cases of metastasis (which takes place frequently), a combination of chemotherapy, radiation therapy, and surgical procedures may be used The prognosis of Somatostatinoma depends upon many factors including the stage of the tumor, the age and overall [dovemed.com]

  Owing to the extensive tumoral localisation and the generally poor condition of the patient, no surgical procedure was performed. Octreotide treatment (0.5 mg/day subcutaneously) was started. [gut.bmj.com]

• Localized Pain

  Usually, there are numerous neurofibromas with onset at different ages; some of them causing local pain and pruritus; a major impact regarding the quality of life is registered because of them (42,44). [spandidos-publications.com]

• Steatorrhea

  Somatostatinoma syndrome occurs in those with a functioning pancreatic SSoma with manifestations including diabetes mellitus, cholelithiasis, diarrhea, weight loss, steatorrhea and hypochlorhydria. [orpha.net]

  […] distinguished from, their pancreatic counterparts by a frequent association with type I neurofibromatosis, the presence of psammoma bodies, the less frequent presence of metastatic disease, and the absence of somatostatinoma syndrome (diabetes mellitus, steatorrhea [ncbi.nlm.nih.gov]

• Dyspepsia

  Cardinal manifestations of a somatostatinoma include gallstones, mild diabetes mellitus, steatorrhoea, diarrhoea and dyspepsia. [ncbi.nlm.nih.gov]

  Other symptoms may include dyspepsia, weight loss, anemia, and hypochlorhydria. [autopsyandcasereports.org]

• Hypertension

  He flushed intermittently and had occasional tachycardia and hypertension. Levels of serum serotonin and urinary 5-hydroxyindoleacetic acid were normal. [jamanetwork.com]

  Materials and methods: D.N., a 42-year-old male patient with a 15 yr history of mild arterial hypertension and neurofibromatosis, suffered an emergency duodenectomy for superior occlusion, caused by a tumor on the duodenum and the first jejune loop. [enets.org]

  Case Report This is a 43-year-old white male patient with past medical history of hypertension and obesity. [hindawi.com]

  In addition to the issue with PPIs, CgA levels may also be elevated in other illnesses including severe hypertension and renal insufficiency. CgB is also said to be more sensitive to Pheochromocytoma. [ronnyallan.com]

• Jaundice

  A case of von Recklinghausen's disease associated with a somatostatinoma of the pancreas causing obstructive jaundice is described. Discussion on the association of von Recklinghausen's disease with somatostatinoma is presented. [ncbi.nlm.nih.gov]

  However, some symptoms include: Weight loss Pain in the stomach area Back pain Jaundice More than half of patients have jaundice when they first go to the doctor. However, I didn’t notice my gran’s jaundice until the last week she was alive. [raisingawarness.wordpress.com]

  Most SSomas present with non-specific symptoms of abdominal pain, weight loss, painless obstructive jaundice and diarrhea. [orpha.net]

  Jaundice is a medical emergency. Speak to your doctor or go to your local A&E if you think you have jaundice. Blockage in the bowel Sometimes the cancer can block the bowel (bowel obstruction). [cancerresearchuk.org]

• Osteoporosis

  Updated clinical guidelines for diabetes, lipid disorders, obesity management, osteoporosis, and more, as well as essential treatment updates for the medical management of acromegaly, Cushing's Disease, hypercalcemia, and diabetes mellitus. [books.google.ro]

  Rom J Morphol Embryol. 54:201–203. 2013.PubMed/NCBI 62 Poiană C, Carşote M, Neamţu MC, Avramescu ET, Vasilescu F, Terzea D, Păun D, Trifănescu R and Dănciulescu Miulescu R: Well-differentiated neuroendocrine tumor and osteoporosis: Incidental findings [spandidos-publications.com]

Diagnosing somatostatinomas requires a multitude of invasive and non-invasive tests. A complete blood count, biochemical profile and somatostatin serum levels (fasting) are the initial steps towards a successful diagnosis. Serum levels of this hormone that exceed 100 pg/ml are indicative of a tumor; patients tend to display a significant increase in these values.

A computerized tomography (CT) scan with intravenous contrast enhancement and magnetic resonance imaging (MRI) are the two radiologic modalities initially employed [7]. They are considered of equal value when assessing the existence of a possible somatostatinoma, with the MRI being deemed superior to a CT scan only in the terms of skeletal and hepatic metastasis detection [8].

Endoscopic ultrasonography (EUS) can aid towards the diagnosis of a somatostatinoma accompanied by potential metastatic tumors in the lymph nodes; its contribution is limited in the illustration of distant metastasis. It also enables the evaluation of gastric pH to confirm hypochlorhydria. Finally, a fine needle aspiration (FNA), guided by ultrasonography, can be performed in order to cytologically analyze the lesion and confirm its type [9] [10].

• Hypochlorhydria

  Somatostatinoma syndrome occurs in those with a functioning pancreatic SSoma with manifestations including diabetes mellitus, cholelithiasis, diarrhea, weight loss, steatorrhea and hypochlorhydria. [orpha.net]

  She exhibited features of somatostatinoma "inhibitory syndrome" characterized by mild nonketotic hyperglycemia, hypochlorhydria, cholelithiasis, steatorrhea, anemia, and weight loss. [ncbi.nlm.nih.gov]

  Steatorrhea or diarrhea episodes are common and individuals tend to report up to ten foul-smelling stools per day; achlorhydria or hypochlorhydria is a frequent finding but does not usually lead to any remarkable complaint. [symptoma.com]

  […] secretes somatostatin. somatostatinoma Delta cell tumor A somatostatin-producing tumor of pancreatic islet delta cells, characterized by ↓ gastric acid secretion and metastasis to liver and bone; it is associated with DM, cholelithiasis, steatorrhea, and hypochlorhydria [medical-dictionary.thefreedictionary.com]

  Clinical features Only rarely associated with somatostainoma syndrome (diabetes, cholecystolithiasis, steatorrhea, hypochlorhydria, Endocr Relat Cancer 2008;15:229 ) Hard to localize preoperatively May be in duodenal wall May have psammoma bodies Clinical [pathologyoutlines.com]

Initial treatment consisted of right pancreatectomy with preservation of the pylorus. [ncbi.nlm.nih.gov]

Surgery is the main treatment for somatostatinoma, other treatments are available to you if surgery is not possible. The main treatment for somatostatinoma is surgery. Some cancerous somatostatinomas have already spread when they are diagnosed. [cancerresearchuk.org]

Of the patients with metastatic and/or locally advanced disease, 10 of the 21 were dead from 9 months to 31/2 years after treatment. [barnardhealth.us]

Surgical resection is the main treatment for early stage disease. Other treatment options include somatostatin analogue, molecular targeted therapy, and cytotoxic chemotherapy. [hindawi.com]

If diagnosed early in the absence of distant metastases the prognosis of papillary somatostatinoma with tumour resection is excellent. [ncbi.nlm.nih.gov]

prognosis compared to those with poor health Age of the individual: Older individuals generally have poorer prognosis than younger individuals Whether the tumor is occurring for the first time, or is a recurrent tumor. [dovemed.com]

Some somatostatinomas are associated with NF1, MEN1 and Von Hippel-Lindau syndromes; the etiology of their sporadic counterparts is unclear. [codes.iarc.fr]

Etiology Some SSomas are components of familial endocrine tumor syndromes. The cause of sporadic SSomas is not clear. [orpha.net]

In our previous study, 13 it was very difficult to differentiate the etiology of large subepithelial tumors, especially those larger than 9 cm in diameter, using only endosonographic characteristics. [e-ce.org]

(Etiology) The exact cause of Somatostatinoma development is unknown A majority of the tumors occur sporadically (about 95% of them), while the rest are inherited (familial Somatostatinoma) Research scientists believe that the cause of the condition is [dovemed.com]

The functioning and nonfunctioning tumor types are then fully discussed, covering epidemiology, diagnosis, morphology and prognosis of each entity. [books.google.com]

Pancreatic Somato - statinoma 2/3rds in head Duodenal somatostatinoma usually ampullary/ periampullary Get psamomma bodies Associated with Von Recklinghausen’s disease; can rarely occur elsewhere Rarely associated with Somato - statinoma syndrome Epidemiology [gastroenterologybook.com]

Summary Epidemiology The estimated incidence is of 1/40,000,000. Approximately 80 cases of pancreatic SSoma have been reported to date but this is probably an underestimate. Clinical description SSomas usually range in size from 3-11cm. [orpha.net]

Epidemiology, clinical features and diagnosis of gastroenteropancreatic endocrine tumours. Ann Oncol 2001;12 Suppl 2: S95-9. http://dx.doi.org/10.1093/annonc/12.suppl_2.S95 Maggard MA, O'Connell JB, Ko CY. [portalnepas.org.br]

We also review the potential effects of somatostatin on glucose homeostasis and discuss the underlying pathophysiologic mechanisms. [ncbi.nlm.nih.gov]

[…] cell tumor, malignant Definitions Pancreas ICD-O-3 topography code: C25 ICD10: C25 A somatostatinoma is a functionally active and usually malignant endocrine tumour with evidence of D-cell differentiation and clinical symptoms reflecting the diverse pathophysiologic [codes.iarc.fr]

1 Department of Endocrinology, School of Medicine with the Division of Dentistry, Medical University of Silesia, Katowice, Poland; 2 Department of Endocrinology, School of Medicine with the Division of Dentistry, Chair of Pathophysiology and Endocrinology [endocrine-abstracts.org]

Pathophysiology [ edit ] In a normal subject actions of somatostatin include: In the anterior pituitary gland, the effects of somatostatin are: Inhibit the release of growth hormone thus opposing the effects of growth hormone-releasing hormone (GHRH) [en.wikipedia.org]

Specialists note that 95% of somatostatinomas occur sporadically, therefore it is very difficult to foresee and prevent the disease. Symptoms of somatostatinoma The signs of this disorder depend on the size and the place of the tumor. [treatendocrine.com]

However, owing to the proximity of the tumor to the ampulla of Vater, a sphincteroplasty was conducted to prevent potential obstruction. [jmedicalcasereports.biomedcentral.com]

In cases where the tumor is located at a place where it cannot be resected then only chemotherapy is done to kill the cancer cells and prevent any further progression of the tumor. [epainassist.com]

Currently, there are no specific methods or guidelines to prevent Somatostatinoma. [dovemed.com]

1. House MG, Yeo CJ, Schulick RD. Periampullary pancreatic somatostatinoma. Ann Surg Oncol. 2002;9:869–874.
2. Tanaka S, Yamasaki S, Matsushita H, et al. Duodenal somatostatinoma: a case report and review of 31 cases with special reference to the relationship between tumor size and metastasis. Pathol Int. 2000;50:146–152.
3. Nesi G, Marcucci T, Rubio CA, et al. Somatostatinoma: clinico-pathological features of three cases and literature reviewed. J. Gastroenterol. Hepatol. 2008;23(4):521-6.
4. Mao C, Shah A, Hanson DJ, Howard JM. Von Recklinghausen's disease associated with duodenal somatostatinoma: contrast of duodenal versus pancreatic somatostatinomas. J Surg Oncol. 1995;59:67–73.
5. Doherty GM. Rare endocrine tumours of the GI tract. Best Pract Res Clin Gastroenterol. 2005;19:807–817.
6. Cappelli C, Agosti B, Braga M, et al. Von Recklinghausen's neurofibromatosis associated with duodenal somatostatinoma. A case report and review of the literature. Minerva Endocrinol. 2004;29:19–24.
7. King CM, Reznek RH, Dacie JE, Wass JA. Imaging islet cell tumours. Clin Radiol. 1994;49:295–303.
8. Debray MP, Geoffroy O, Laissy JP, et al. Imaging appearances of metastases from neuroendocrine tumours of the pancreas. Br J Radiol. 2001;74:1065–1070.
9. Stelow EB, Woon C, Pambuccian SE, et al. Fine-needle aspiration cytology of pancreatic somatostatinoma: the importance of immunohistochemistry for the cytologic diagnosis of pancreatic endocrine neoplasms. Diagn Cytopathol. 2005 Aug;33(2):100-5.
10. Mori Y, Sato N, Taniguchi R, et al. Pancreatic somatostatinoma diagnosed preoperatively: report of a case. JOP. 2014 Jan 10;15(1):66-71.