The present study reports a case of recurrent malignant pelvic
solitary fibrous tumor (SFT) that induced non-
islet cell tumor hypoglycemia via high-molecular-weight
insulin-like growth factor-II in a 72-year-old male patient. The
tumor recurred ~12 years after the complete resection of the original mass. The recurrent
tumor, which had directly invaded the left ureter and perirectal fat tissue, could not be completely excised due to its fragility and adhesiveness. At 13 days post-surgery, the patient presented with rectal perforation, and an urgent rectal resection and
colostomy was performed. Neither recurrence of the
tumor nor
hypoglycemic symptoms were observed 9 months after the surgery. High molecular weight
insulin-like growth factor-II was detected in the serum and
tumor specimens by western blot analysis and immunohistochemistry. The present case report suggests that certain SFTs can relapse even ≥10 years after a presumed complete resection of the primary
tumor, and that performing a safe and complete resection of these
tumors can be challenging, due to their adhesiveness or physical presentation; therefore, the indications for surgery should be considered with caution.