Somatostatinoma

From Dog
Histological appearance of a somatostatinoma[1]

Somatostatinoma are a rare slow-growing neuroendocrine neoplasia of the canine pancreatic islet cells.

Pancreatic somatostatinomas are characterized by hypersomatostatinemia and often metastasize to regional lymph nodes and liver.

Somatostatinomas originate from D (delta; δ) cells of the pancreas and gastrointestinal tract and are often an incidental finding on autopsy or during exploratory laparotomy. Its release is regulated by ingested and circulating nutrients as well as histamine, insulin, prostaglandins, opiates and gastrointestinal hormones[2].

Concurrent gastrinoma have also been reported[3].

Gastrointestinal somatostatinoma are clinically distinct from pancreatic somatostatinoma, often resulting in biliary obstruction or intestinal obstruction. Hypersomatostatinemia is not usually a feature of this tumor.

Clinical symptoms can be vague and include glucose intolerance, cholelithiasis, maldigestion, diarrhea, steatorrhea, hypochlorhydria and weight loss.

Diagnosis usually requires histological examination of pancreatic biopsy, increased levels of circulating somatostatin. Definitive diagnosis require immunhistochemical staining.

Treatment usually requires surgical excision. Chemotherapy with streptozocin has been trialed[4].

References

  1. Look for a diagnosis
  2. Schusdziarra V (1983) Somatostatin - physiological and pathophysiological aspects. Scand J Gastroenterol Suppl 82:69-84
  3. Hoenerhoff M & Kiupel M (2004) Concurrent gastrinoma and somatostatinoma in a 10-year-old Portuguese water dog. J Comp Pathol 130(4):313-318
  4. De Nutte, N et al (1978) Pancreatic hormone release in tumor associated with hypersomatostatinemia. Diabetologia 15:227