HYPOGLYCEMIA IN A PATIENT WITH A FIBROUS TUMOR. STUDIES OF THE MECHANISM OF THE HYPOGLYCEMIA

Hypoglycemia, an atypical early sign of hepatocellular carcinoma

BACKGROUND

Hypoglycemia is extremely uncommon as the first presentation of hepatocellular carcinoma, and it occurs predominantly as a paraneoplastic manifestation.

METHODS

We report a case of a 38-year-old-man positive for hepatitis B surface antigen with high-serum viremia who presented with symptoms of acute severe hypoglycemia.

RESULTS

Laboratory tests confirmed hypoglycemia (serum glucose 1.54 mmol/L) with undetectable serum-C peptide (<0.5 µIU/mL) and slightly increased serum insulin concentration (35 µIU/mL). Alpha-fetoprotein serum level was 75,625 ng/mL. Abdominal ultrasonography and computed tomography revealed a big vascularized mass of 13 cm in diameter occupying most of the right lobe of the liver and an (18)F-fluoro-2-deoxy-D-glucose positron-emission tomography revealed a predominant uptake of glucose by the tumor mass.

CONCLUSIONS

These findings indicate that hepatocellular carcinoma-associated hypoglycemia may be due exclusively to increased glucose utilization by the tumor mass.

Glucose utilization in a patient with hepatoma and hypoglycemia. Assessment by a positron emission tomography

Tumor glucose use in patients with non-islet-cell tumors has been difficult to measure, particularly in hepatoma, because of hepatic involvement by neoplasm. We studied a patient with nonhepatic recurrence of hepatoma after successful liver transplantation. Tumor tissue contained messenger RNA for insulin-like growth factor-II (IGF-II), and circulating high molecular weight components and E-peptide of IGF-II were increased. Glucose use measured by isotope dilution with [3-3H]glucose was 7.94 mg/kg fat-free mass per min, and splanchnic glucose production was 0.93 mg/kg fat-free mass per min. Glucose uptake and glucose model parameters were independently measured in tissues by positron emission tomography with 18F-fluoro-2-deoxy-D-glucose. Glucose uptake by heart muscle, liver, skeletal muscle, and neoplasm accounted for 0.8, 14, 44, and 15% of total glucose use, respectively. Model parameters in liver and neoplasm were not significantly different, and glucose transport and phosphorylation were twofold and fourfold greater than in muscle. This suggests that circulating IGF-II-like proteins are partial insulin agonists, and that hypoglycemia in hepatoma with IGF-II production is predominantly due to glucose uptake by skeletal muscle and suppression of glucose production.

Spontaneous hypoglycemia associated with hemangiopericytoma of the kidney

We report the third case of renal hemangiopericytoma associated with spontaneous hypoglycemia. The clinical and pathological features suggest that excessive glucose storage by the tumor is an important factor in the pathogenesis of the hypoglycemia. Other possible mechanisms producing hypoglycemia associated with mesenchymal tumors are reviewed.

Mesenchymal tumors associated with hypoglycemia: case report and review of the literature

Hypoglycemia secondary to malignant tumors is rare. Mesenchymal tumors of nonpancreatic origin are the most common tumors associated with the hypoglycemia syndrome, and the clinical features of 115 reported cases are reviewed. The major anatomic distributions of the tumors are thoracic (30%) abdominal (65%), and uncommon locations (less than 5%). Approximately 50% of the tumors were resectable (59 patients), and in 60% the surgical procedure was curative. In the remaining 40% local recurrence predominated related to site of tumor and presence of contiguous organ invasion. The application of multimodality adjuvant therapy for hypoglycemia associated mesenchymal tumors should be based on an understanding of the natural history of the tumor.

Ectopic insulin and Occam's razor: reappraisal of the riddle of tumour hypoglycaemia

The concept of ectopic insulin production is challenged on the basis of a review of 120 cases from the literature on extrapancreatic tumours associated with hypoglycaemia in which insulin or insulin-like activity were measured. No case met two or more of five criteria of ectopic hormone production. The evidence indicates that hypoglycaemia of extrapancreatic tumours cannot be attributed to insulin. In those rare cases in which plasma insulin was reported as high, pancreatic beta-cells could not be excluded as the source of insulin. Interestingly, many of these dubious cases had carcinoid histology. The review also points out a close association between some spindle-cell tumours and carcinoid tumours which may be relevant to discussion on the disputed origin of some "mesothelial" tumours. Nonsuppressible insulin-like activity (NSILA) consists of a number of factors mimicking insulin activity which compete with insulin or proinsulin for membrane receptors and may crossreact in bioassays, immunoassays, and receptor assays. The question of whether one or several of these substances may be responsible for extrapancreatic hypoglycaemia remains to be elucidated.