Retroperitoneal hemangiopericytoma associated with hypoglycemia: report of a case.

A 34-year-old woman had episodes of hypoglycemic attack 8 years after a surgical resection of a retroperitoneal hemangiopericytoma. In spite of normal levels of serum IRI, insulin radioreceptor assay demonstrated high level of plasma ILA (insulin like activity). The patient underwent resection of a recurrent retroperitoneal tumor with metastatic lesions of the liver. Postoperatively, ILA level in plasma by insulin radioreceptor assay decreased, and hypoglycemic attacks disappeared. Therefore, this associated hypoglycemia was presumed to be not caused by excess glucose consumption by the tumor, not by excess secretion of IRI by the tumor, but caused by the presence of high level of ILA related to the tumor.