A PPoma is a tumour of the gamma cells, which make up 10% of the islet cells of the pancreas. These cells produce 93% of the body's pancreatic polypeptide (PP). PP is thought to weakly inhibit the release of pancreatic enzymes and gastric acid, and inhibit contraction of the gallbladder. Levels of this hormone are elevated in 75% of patients with a PPoma.
Although there have been reports of an erythematous pruritic papular rash associated with PPoma that resolves once the tumour is removed, there is no syndrome associated with the increased release of PP into the bloodstream. The features of a PPoma when presented are related to tumour, its size and how it affects adjacent organs. Patients may present with abdominal pain and jaundice and the tumour has usually metastasised by the time it is detected.
A tumour that hasn't metastasised can be treated by excision. Otherwise debulking may be done. Chemotherapy and hepatic embolisation may also reduce the tumour load.