Hypoglycemia Secondary to Paraneoplastic Syndrome Mediated By Elevated Prepro IGF-2 in a Patient with Advanced Liposarcoma

Presentation Number: MON 289
Date of Presentation: April 3rd, 2017

Christina Elizabeth Pentlow* and Rifka C Schulman
Long Island Jewish Hospital, NY

Abstract

Introduction: Hypoglycemia is known to be caused by paraneoplastic elevation of IGF-1 and -2 levels. Prepro IGF-2 (which is then cleaved to form IGF-2) has been shown to cause hypoglycemia when IGF-2 levels are normal. The IGF-2: IGF-1 ratio is used to reflect such levels, with a ratio >10 being significant. (1)

Clinical Case: An 84 year old male with history of de-differentiated recurrent liposarcoma, status post excision several years prior, originally presented to an outside hospital with altered mental status over the past few weeks associated with lethargy and slurred speech. He was found to have a fingerstick value of 25 mg/dl. Mental status was reported to improve with D5W. He was transferred to Long Island Jewish Hospital. CT scan of the abdomen performed 8 days prior to admission revealed large heterogeneous intraabdominal masses measuring approximately 20 x 15 cm on the right and 26 x 20 cm on the left. Initial serum glucose was 24 mg/dl. 3 AM cortisol level was 13 ug/dl (8AM, 8-19). TSH was mildly elevated at 5.65 uIU/ml (0.27-4.20) with a free T4 of 0.73 ng/dl (0.9-1.8). Creatinine on admission was 0.76 mg/dl, with normal transaminase levels. C peptide and insulin levels drawn at the time of a serum glucose of 56 mg/dl were 0.1 ng/ml (0.8-3.90) and <0.2 uU/ml (3-17) respectively. Sulfonylurea screen was negative. IGF-1 was 24 ng/ml (34-165), and IGF-2 was 647 and 517 ng/ml on repeat (333-967). His IGF-2: IGF-1 ratio was found to be elevated at 27.

For management, in conjunction with D10W, he was started on prednisone 30 mg daily. He continued to be hypoglycemic and was then changed to intravenous (IV) steroids out of concern for decreased absorption. Initially he was given hydrocortisone 50 mg IV q 8h, but due to persistent hypoglycemia this was increased to 75 mg IV q 8h while D10W was continued. He was continued on this regimen until partial surgical resection was performed. He had also been started on levothyroxine 25 mcg oral daily for hypothyroidism. Postoperatively he was successfully tapered off steroids and maintained a normal glucose without the need for intravenous dextrose. Pathology revealed recurrent de-differentiated liposarcoma.

He was readmitted 8 days after discharge with shortness of breath and found to have a right sided pulmonary embolus. He was also found to have hypoglycemia with a serum glucose of 47 mg/dl. He was placed on prednisone, which was titrated to 15 mg twice daily after having been found to have a morning glucose of 40 mg/dl on once daily dosing. Glucose levels improved on twice daily prednisone. IV fluids were not given out of concern for right heart strain. He was not deemed to be a surgical candidate. The patient and his family ultimately made the decision to transfer to hospice care.

Conclusion: We present a rare case of hypoglycemia due to paraneoplastic elevation of prepro IGF-2.

 

Nothing to Disclose: CEP, RCS