Primary malignant fibrous histiocytoma of the lung: IGF-II producing tumor induces fasting hypoglycemia.

Augmented glucose utilisation or secretion of insulin-like-growth-factor II (IGF-II) are discussed as important pathogenetic factors in tumor-associated hypoglycemia (Doege-Potter Syndrome) with suppressed insulin and C-peptide levels. Primary malignant fibrous histiocytoma of the lung is an uncommon neoplasia and its association with hypoglycemia is rare and the causal relationship remains unclear. - We report a 57-year-old male with spontaneous hypoglycemia (1.67 mmol/l) due to a primary malignant fibrous histiocytoma of the lung, secreting IGF-II. Insulin (0.10 nmol/l; normal range 0.33-1.2) and C-peptide (3.0 mIU/l; 5-25) levels were suppressed in combination with low levels of growth hormone (<0.5 ng/ml; <7 ng/ml) and IGF-I (<66.0 ng/ml; 70-246). The elevated IGF-II level (787 ng/ml; 300-500) and decreased IGF-binding protein 3 (1.6 mg/l; 2-5) indicated a high free IGF-II activity. After surgery (resection of the right upper lobe), glucose (4.4 mmol/l), insulin (9.0 mIU/L) and C-peptide (0.84 nmol/l) levels returned to normal. Serum IGF-I (289 ng/ml) and the IGF-I/IGF-II ratio (<0.08 preoperative vs. 0.41 postoperative; >0.20) increased to the normal reference range. - In conclusion, malignant fibrous histiocytoma (MFH) is rarely described presenting as tumor-induced hypoglycemia. Doege-Potter Syndrome in MFH seems to be related to tumor-associated IGF-II production.