Case report: hypoglycemia secondary to a meningioma

Tumor-Induced Hypoglycemia: An Unusual Case Report and Review of Literature

Objective

To describe a rare case of pheochromocytoma presenting with hypoglycemia.

Methods

We describe a rare case of pheochromocytoma presenting with a hypoglycemic seizure. Our article includes our differentials, work up, and management.

Results

Our patient had non–islet-cell tumor hypoglycemia that was non-insulin mediated, as noted by low insulin levels. His hypoglycemia was likely multifactorial and mediated by different mechanisms. We describe the rare case and review the causes of tumor-induced hypoglycemia.

Conclusion

Pheochromocytomas can rarely present with hypoglycemia and are associated with a poor prognosis.

Management of endocrine disease: a clinical update on tumor-induced hypoglycemia

Tumor-induced hypoglycemia (TIH) is a rare clinical entity that may occur in patients with diverse kinds of tumor lineages and that may be caused by different mechanisms. These pathogenic mechanisms include the eutopic insulin secretion by a pancreatic islet β-cell tumor, and also the ectopic tumor insulin secretion by non-islet-cell tumor, such as bronchial carcinoids and gastrointestinal stromal tumors. Insulinoma is, by far, the most common tumor associated with clinical and biochemical hypoglycemia. Insulinomas are usually single, small, sporadic, and intrapancreatic benign tumors. Only 5-10% of insulinomas are malignant. Insulinoma may be associated with the multiple endocrine neoplasia type 1 in 4-6% of patients. Medical therapy with diazoxide or somatostatin analogs has been used to control hypoglycemic symptoms in patients with insulinoma, but only surgical excision by enucleation or partial pancreatectomy is curative. Other mechanisms that may, more uncommonly, account for tumor-associated hypoglycemia without excess insulin secretion are the tumor secretion of peptides capable of causing glucose consumption by different mechanisms. These are the cases of tumors producing IGF2 precursors, IGF1, somatostatin, and glucagon-like peptide 1. Tumor autoimmune hypoglycemia occurs due to the production of insulin by tumor cells or insulin receptor autoantibodies. Lastly, massive tumor burden with glucose consumption, massive tumor liver infiltration, and pituitary or adrenal glands destruction by tumor are other mechanisms for TIH in cases of large and aggressive neoplasias.

Intracranial malignant meningioma with abdominal metastases associated with hypoglycemic shock: a case report

A thirty-year-old male with an intracranial malignant meningioma, first diagnosed 9 years ago, with three recurrences was admitted with a hypoglycemic shock. The blood glucose level was 17 mg/dl, requiring treatment with high doses of intravenous and oral dextrose for improvement. A large metastatic tumor in the liver was noted. All hormones and peptides influencing blood glucose levels were in their normal levels. Chemo-embolization and injection of anti-cancer drugs was employed in the management of the metastatic tumor. Positron emission tomography was performed to measure the glucose metabolism of the abdominal tumor and it indicated that glucose consumption within the tumor was much elevated than the surrounding abdominal organs. Hypoglycemia secondary to primary hepatoma or islet-cell cancer has been frequently described, but a complication of metastatic meningioma is an exceedingly rare event. Elevated glucose consumption within the tumor might be addressed as one of the reasons for hypoglycemia, not due to the elevated serum levels of insulin or IGF, but due to the closely related blood glucose level.

Hepatic and pulmonary metastases from a meningeal hemangiopericytoma and severe hypoglycemia due to abnormal secretion of insulin-like growth factor: a case report

A 42-year-old woman was hospitalized for severe hypoglycemic coma. She had a voluminous hepatic metastasis and multiple small lung metastases from a meningeal hemangiopericytoma initially operated on 11 years earlier. High blood levels of an abnormal form of insulin-like growth factor type 2 (IGF II) associated with low blood levels of insulin, growth hormone, IGF I, and IGF BP3 were observed. After surgical resection of the liver and pulmonary metastases, serum glucose levels and hormonal abnormalities returned to normal.

Hypoglycemia Attributable to Insulin-Like Growth Factor-II Prohormone-Producing Metastatic Leiomyosarcoma

OBJECTIVE

To review the causes of nonpancreatic tumor-associated hypoglycemia and report the first case of hypoglycemia attributable to a leiomyosarcoma, which did not cause hypoglycemia in its primary site but only after metastasizing.

METHODS

A case report is presented of a 62-year-old man with a gastric leiomyosarcoma diagnosed and surgically treated 8 years previously, who was found to have 14 large, rounded masses in his liver and a blood glucose level of 19 mg/dL. Biopsy of the largest mass revealed a leiomyosarcoma.

RESULTS

Evaluation of the cause of the hypoglycemia revealed that circulating insulin, connecting peptide, proinsulin, insulin-like growth factor-I (somatomedin C), and insulin-like growth factor-II levels were below normal, whereas the insulin-like growth factor-II prohormone concentration was increased twofold. Basal and corticotropin-stimulated serum cortisol values were normal.

CONCLUSION

This is the first case report of hypoglycemia occurring only after metastasis of a leiomyosarcoma. A possible causal relationship between the hypoglycemia and the increased circulating insulin-like growth factor-II prohormone is suggested, and alternative explanations and treatment are discussed.