Endocrine Abstracts

Introduction: Various non pancreatic tumors can cause hypoglycemia. Usually they are mesenchymal, retroperitoneal tumors or fibrosarcomas. Hemangiopericytoma is a rare type of mesenchymal tumor, which mostly develops in soft tissue and originates from the Zimmermann’s pericyte (modified smooth muscle cells).

Case report: Fifty-nine-years old female patient with hypoglicemia was addmited to our department. Physical finding showed mild obesity and hypertension. Endocrine testing confirmed fasting hypoglycemia (about 2.0 mmol/l). Seventy-two hours fasting test was interrupted after 12 h with glycemia 0.8 mmol/l, and low levels of insulin, C peptide and IGF1. Ultrasound and multi slice computed tomography (MSCT) showed massive vasculated intraperitoneal tumor, size 120×175×196 mm. She underwent surgery and large lobulated vasculated tumor was found in right lower hemiabdomen connected to the omentum. Histological and immunohistological finding confirmed hemangiopericytoma (grade II-Trojani-Coindre score: 5/9 with Ki67:10%). Postoperatively, no hypoglycemia was detected. Insulin, C peptide and IGF1 were in the normal range.

Conclusion: Hypoglycemia, detected in patients with large non pancreatic tumors occurs due to expression and release of immature form of IGF2 molecules, pro-IGF2, which bounds to IGF binding protein 3 (IGFBP3) and remains active. This complex binds to insulin receptors in muscles to promote glucose transport and to insulin receptor in liver and kidney to reduce glucose output. Also, it binds to receptors for IGF1 in the pancreatic beta cells and in pituitary which leads to inhibition of insulin secretion and suppression of GH release, respectively. GH and IGF1 values are decreased, IGF2 values may be increased but often are normal. Immature higher-molecular-weight form of IGF2 can only be detected by special laboratory techniques.