Endocrine Abstracts

A 91year-old woman was admitted after collapsing at home. She was an ex-smoker with history of chronic obstructive airway disease (COAD), atrial fibrillation , osteoporosis and colonic polyps. On examination, she had clinical signs of chest infection with normal blood pressure and no significant postural drop .Blood glucose was 2.6 millimoles pre litre on admission. Further serial plasma glucose estimations revealed persistant fasting hypoglycaemia( 1.9 to 2.6 millimoles per litre), leading to generalised tonic clonic fits on the ward. She had normocytic anaemia with normal liver, bone, thyroid, renal function, growth hormone and insulin-like-growth factor I level. Short synacten test was normal . Chest x ray revealed cardiomegaly and changes consistent with COAD. Computerized tomogram of abdomen was normal except for a few gall stones. A clinical diagnosis of insulinoma was made, hence insulin, C-peptide levels and Octreotide scan was requested. She was initially treated with intravenous dextrose and diazoxide which failed to improve her symptoms of hypoglycaemia. Unfortunately, she developed myocardial infarction and congestive cardiac failure and her clinical condition deteriorated leading to her death. Autopsy revealed a bronchogenic carcinoma with no evidence of metastasis. Insulin and c peptide results received after her death were normal, thus excluding insulinoma. A diagnosis of tumour induced hypoglycaemia (Doege-potter syndrome) was made.
Doege-potter syndrome is relatively uncommon . Only a few cases have been described, the pathophysiologic mechanism of the syndrome have not been fully been elucidated as yet. Possible mechanisms involved are tumour-induced augmented glucose utilization, IGF II production or nonmetastatic manifestation of malignancy. This case emphasises the need to consider underlying malignancy as a differential diagnosis for hypogycaemia. The ectopic production of hormone by tumour is important to appreciate as relevant endocrine feature may antedate the appearance of further evidence of tumour .