Abstract
Solitary fibrous tumor (SFT) is a rare mesenchymal neoplasm that may present with non-islet cell tumor hypoglycemia (NICTH), also referred to as Doege-Potter syndrome, primarily due to aberrant secretion of big-IGF2. However, not all big-IGF2-producing SFTs result in hypoglycemia, implying the involvement of additional pathogenic factors. This article reports a case of a 60-year-old male who presented with hypoglycemic syncope secondary to Doege-Potter syndrome. Preoperative imaging identified a large, highly vascularized SFT, approximately 20 cm in diameter, located in the right thoracic cavity. Intraoperative continuous glucose monitoring (CGM) recorded a gradual normalization of blood glucose levels following sequential ligation of three dominant tumor vessels originated from veins- prior to tumor resection - underscoring the essential role of tumor vascular in facilitating big-IGF2 release. Our findings provide the first direct evidence that tumor vasculature is critical for manifesting clinically significant hypoglycemia, thereby complementing established molecular mechanisms such as IGF2 overexpression and impaired pro-IGF2 processing. These insights advance the understanding of NICTH pathogenesis and hold meaningful implications for refining surgical management strategies.