Somatostatin

Specimen:

10 mL blood in a lithium heparin tube.

Plasma must be stored frozen until assay.

Method:

Immunoassay.

Reference Interval:90-150 ng/L.
Application:

Diagnosis of functional somatostatinoma (Diabetes mellitus, cholelithiasis, steatorrhoea, hypochlorhydria).

Functional tumours usually occur as islet cell tumours in the pancreas. Some non-functional somatostatinomas (usually duodenal) may be diagnosed by an increase in somatostatin after infusion of calcium and pentagastrin.

Interpretation:

Hypersomatostatinaemia with a somatostatinoma syndrome and a pancreatic tumour is diagnostic of a functional somatostatinoma.

Reference:

Tomassetti P et al. Ann Oncol 2001; 2: 95-99.