Abstract
We report a case of solitary fibrous tumor of the pleura, which produced high molecular-weight insulin-like growth factor II (big IGF-II). A 82-year-old woman was referred to our hospital with a large mass in the right thorax. It was diagnosed as a solitary fibrous tumor by needle biopsy. The patient was primarily followed up with no therapy. Four months later, she was admitted to our hospital with a hypoglycemic attack. Endocrinological investigations revealed low values of urinary C-peptiede and serum IRI. Extirpation of the thoracic tumor was performed, because the hypoglycemia was suspected to be related to the tumor. After the operation, the hypoglycemic attack was completely resolved on the second postoperative day, and the endogenous insulin level returned to normal. We investigated the size of IGF-II in serum before and after the operation by Western immunoblot analysis. Most of the serum IGF-II in the patient was detected at 20.9kDa, whereas, after surgical resection of the tumor, the high molecular weight IGF-II was not detected in the patient's serum. At three years after the operation, there is no sign of recurrence. We suggest that the high molecular weight IGF-II was produced by SFT and caused hypoglycemic attack.
