A80-4-21 A Rare Case of Malignant Solitary Fibrous Tumor of the Pleura Complicated by Doege-Potter Syndrome

Abstract Introduction Solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms associated with a fusion in the NAB2-STAT6 gene, often involving the pleura. With an incidence of 1 per 1,000,000, most SFTs are indolent; however, malignant transformation occurs in 10-15% of intrathoracic SFTs. Rarely, SFTs are associated with paraneoplastic syndromes. We present a case of a malignant pleural SFT complicated by hypoglycemia due to Doege-Potter syndrome (DPS), an insulin-like growth factor (IGF) 2-mediated paraneoplastic syndrome. Case A 55-year-old male, lost to follow-up for a previously unspecified lung mass, now presents with several weeks of cough and dyspnea. Chest imaging revealed a dramatic increase in the size of the known mass, now occupying nearly the entire hemithorax. This lung lesion was initially identified 25 years prior and was presumed to be a calcified hematoma related to prior trauma. When seen by pulmonology 7 years prior to current admission, continued surveillance was recommended. Unfortunately, the patient failed to follow up, until now, being symptomatic. Repeat CT scan demonstrated a 19.1 × 10.9 × 14 cm lobulated mass in the right hemithorax. The patient underwent CT-guided percutaneous biopsy, revealing the diagnosis of SFT with malignant transformation. The biopsy was complicated by hemothorax requiring thoracotomy for hemostasis. Hospital course was further complicated by refractory hypoglycemia despite a continuous infusion of concentrated dextrose solution of D30 as well as high dose glucocorticoids. Laboratory analysis found an elevated IGF2:IGF1 ratio (10), confirming Doege-Potter syndrome. Surgical resection was attempted despite the elevated surgical risks highlighted by tumor size and vascularity. While full resection of the tumor was achieved, the procedure resulted in massive intraoperative hemorrhage. Despite aggressive resuscitative measures, refractory hemorrhagic shock ensued, with the patient ultimately succumbing to multiorgan failure. Discussion This case highlights a rare presentation of malignant pleural SFT complicated by DPS, emphasizing the challenges of managing advanced disease. Surgical resection remains the definitive treatment for both SFT and DPS, as chemotherapy generally yields poor response. For nonresectable tumors, management options are limited, although local-regional therapies such as embolization for tumor debulking have been described. When paraneoplastic syndrome such as DPS is involved, medical management with dextrose infusions and glucocorticoids may temporize the situation. Management becomes increasingly complex in malignant SFTs due to their vascularity and increased surgical risk, underscoring the need for vigilant surveillance for indolent lesions with malignant potential. Early intervention remains a cornerstone of treatment for SFT. This abstract is funded by: None