SAT174 Doege-Potter Syndrome In A Patient With Solitary Fibrous Tumor Of The Lung

Abstract

Abstract Disclosure: N. Mon: None. S.S. Krishnasamy: None. Doege-Potter Syndrome is a non-islet cell tumor hypoglycemia (NICTH) due to a solitary fibrous tumor (SFT) with overexpression of Insulin-like growth factor 2 (IGF2). We report a case of refractory hypoglycemia in a patient with SFT of the lung. Case presentation: A 67-year-old homeless male with hypertension, chronic smoker presented with altered mental status after his blood glucose was found 34mg/dl by EMS. His confusion improved after D50W. He could not recall the event but he reported that he missed his dinner prior to the event. He denied taking any antidiabetic medications. He was diagnosed with left lung solitary fibrous tumor without metastases a week ago after he presented to ER with dyspnea, cough and wheezing. CT chest reported a 21x15.6x18.7 cm lesion with mass effect on the left hemidiaphragm, mediastinum shift to the right and occluded left lower lobe bronchi. Core needle biopsy of the mass revealed SFT with necrosis. He was discharged with Medrol dosepak 4mg daily for presumptive treatment of COPD exacerbation and a plan for elective surgery. While in the ER his BG improved to 136mg/dl after D50W. Few hours later BG dropped to 42mg/dl and D10W infusion was started. Physical exam was unremarkable except bilateral pedal edema. Work up showed BG 42mg/dl, Insulin 3.3 (2.6-24.9 uIU/mL), C peptide 0.39 (1.1-4.4ng/mL), Proinsulin 4.7 (<18.8pmol/L), beta-hydroxybutyrate <0.05 (0.02-0.27mmol/l), 8AM cortisol 10.7 (7.0-25.0 ug/dl), albumin 3.2mg/dl, HbA1c 5.8%, IGF1 53ng/mL (34-245ng/mL), IGF2 203ng/mL (267-616ng/mL) with a IGF2:IGF1 ratio of 3.8. In our patient, the IGF2:IGF1 ratio was not >10 since his IGF 2 was suppressed by the recent steroid use. The rest of the clinical and biochemical features strongly suggested NICTH. His preoperative evaluation showed new onset HFrEF with volume overload. He underwent staged percutaneous coronary interventions with stents placement. He was given hydrocortisone 50mg q6H then to q8H during hospitalization and discharged home with hydrocortisone 40mg TID. He underwent radical resection of lung tumor after optimization of his cardiac condition. He was on stress dose of steroid during surgery. Since he was on high dose steroid for > 3months, hydrocortisone dose was tapered slowly after the surgery. Final biopsy reported solitary fibrous tumor extending to parenchymal staple line. Tumor cells are positive for CD34 and STAT6, and negative for desmin, SMA, and SOX10. He recovered uneventfully and was discharged home with prednisone 5mg daily and follow up in endocrine clinic. Conclusion: NICTH is a rare paraneoplastic syndrome characterized by low levels of insulin, C-peptide, proinsulin, and beta-hydroxybutyrate. A ratio of IGF-2/IGF-1 more than 10 confirms NICTH; however, normal ratio cannot exclude the diagnosis and factors such as low IGFBP 3 or steroid therapy for other conditions need to be considered. Surgery is the mainstay of treatment. Presentation: Saturday, June 17, 2023