An 84 year old woman, without diabetes mellitus, had recurrent presentations to the hospital with hypoglycaemia, confusion and respiratory distress. She has a known slow growing giant fibrous tumour (17.4 x 10 x 13cm) in her left thoracic cavity, initially found on a CT-imaging of her chest. The tumour was causing weight loss, and increasing shortness of breath on exertion, on a background of smoking and underlying chronic obstructive pulmonary disease.
During one admission, she had recurrent fasting hypoglycaemic episodes, with BGL as low as 1.8 mmol/L, despite good oral intake. Unfortunately, blood collection for plasma glucose, insulin, pro-insulin, C-peptide, and betahydroxybutyrate was missed during these hypoglycaemic episodes by overtime staff, and she was too frail to undergo a prolonged fast. IGF-II measurement also could not be performed.
As fibrous tumours of the lung are known to be associated with hypoglycaemia, a presumptive diagnosis of non-islet cell tumour hypoglycaemia was made. Given that this patient was not a surgical candidate, she was commenced on corticosteroid therapy. No further hypoglycaemia ensued, and her BGLs ranged between 4 – 10mmol/L.
This is a rare but typical case of non-islet cell tumour induced hypoglycaemia. An intra-thoracic tumour induced hypoglycaemia is also known as Doege-Potter syndrome. In the discussion, we will review the reported cases of Doege-Potter syndrome, examine the pathophysiology, and explore the treatment options available.