SESSION TITLE: Disorders of the Pleura 2 SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/09/2018 01:15 pm - 02:15 pm INTRODUCTION: Hypoglycemia due to solitary fibrous tumor of pleura (SFTPs) is known as Doege-Potter syndrome (DPS). SFTPs are rare mesenchymal tumors that are asymptomatic or demonstrate nonspecific symptoms. They can ectopically secrete insulin-like growth factor II (IGF-II) causing hypoglycemia. DPS occurs in less than 5% of SFTP cases with less than 80 cases reported.1 CASE PRESENTATION: Herein, we report a case of recurrent malignant solitary fibrous tumor in a 54-year-old woman who had her first tumor resected 8 years prior without recurrence for 5 years on surveillance imaging. She presented with confusion, severe hypoglycemia, weight loss and digital clubbing. Computed tomography of the chest revealed recurrence of the mass measuring 13.8x9.6x13.6cm. Insulin, proinsulin, and C-peptide levels were undetectable. IGF-II was elevated at 690mg/ml. She was successfully managed with steroids.She subsequently underwent repeat thoracotomy with excision of the mass including visceral pleural, rib section, and pericardium. Histology was consistent with recurrence of malignant solitary fibrous tumor. IGF-II level dropped to 248ng/ml. Her hypoglycemia completely resolved after excision and prednisone taper. DISCUSSION: SFTPs are generally benign tumors but there is a risk of malignant transformation and recurrence. Definitive treatment and amelioration of associated hypoglycemia is achieved by local control of the mass with surgical resection. Prior to resection, hypoglycemia can be managed with glucocorticoids often requiring more than 20mg/day of prednisolone.1 There is no consensus on the use of adjunctive chemoradiation, however it has been utilized in malignant SFTP treatment. 1,2 Prognosis for malignant SFTP is favorable with surgical resection, with reported 5-year survival of 81%.2 CONCLUSIONS: Our case emphasizes the importance of expanding the differential diagnosis for hypoglycemia. Tumor-induced hypoglycemia should be investigated after ruling out common etiologies. SFTs have a good clinical outcome if complete resection is performed with resolution of DPS. Recurrence is not uncommon, therefore life-long surveillance with imaging may be beneficial. Reference #1: Han G, Zhang Z, Shen X, Wang K, Zhao Y, He J, Gao Y, Shan X, Xin G, Li C, Liu X. Doege–Potter syndrome: A review of the literature including a new case report. Medicine. 2017 Jul;96(27). Reference #2: Lococo F, Cesario A, Cardillo G et al: Malignant solitary fibrous tumors of the pleura: retrospective review of a multicenter series. J Thorac Oncol, 2012; 7: 1698–706 DISCLOSURES: No relevant relationships by Rayan Ihle, source=Web Response No relevant relationships by Muhammad Farhan Khaliq, source=Web Response