Spontaneous recurrent hypoglycaemia due to metastatic gatrointestinal stromal tumour (GIST)
Binu Krishnan, Aikaterini Theodoraki & Helen Ward
A 75-year old gentleman presented with symptoms of increasing lethargy, loss of appetite associated with weight loss and constant micturition. A CT scan showed extensive peritoneal mass in the lower abdomen and pelvis with disseminated intraperitoneal malignancy. A CT guided biopsy confirmed a poorly differentiated tumour. Immunohistochemistry showed that all the cytokeratin markers were negative, but vimentin was positive and CD117 (c-kit) was strongly positive, indicating that it was a malignant GIST. In the following two weeks, the patient experienced recurrent episodes of blackouts associated with excessive sweating and was admitted to hospital. The patient showed a suboptimal response to short synacthen test. Blood tests during an episode of spontaneous hypoglycaemia revealed.
While on the ward, he had recurrent episodes of spontaneous hypoglycaemia requiring correction with 10% dextrose infusion. There was no improvement in blood sugars despite treatment with hydrocortisone and octreotide. As an elevated IGF II:IGF I ratio confirmed the diagnosis of non-islet cell hypoglycaemia, the patient was commenced on Growth hormone 0.02 mg/kg subcutaneously daily with successful stabilization of blood sugars.