RESUMO
BACKGROUND: Doege-Potter syndrome is a rare paraneoplastic entity that is often diagnosed incidentally during the work-up of hypoglycemia of unclear etiology. It is characterized by a non-islet cell tumor hypoglycemia mostly associated with solitary fibrous tumors. These uncommon tumors have been reported in <5% of solitary fibrous tumors. Although not unique in its kind, this case is extremely important as this syndrome often conceals unrecognized tumors that can be surgically resolved. CASE PRESENTATION: We present the case of a 59-year-old non-diabetic man with a 2-month history of severe and recurrent fasting hypoglycaemia presenting with severe dyspnea and sweating. Further workup revealed low insulin, C-peptide, and IGF-1 levels and a large right in-trathoracic solitary fibrous tumor. Unfortunately, bioassays for IGF-2 were unavailable at our hos-pital. Nevertheless, as hypoglycemia completely resolved after resection of the mass, Doege-Potter syndrome was highly suspected. CONCLUSION: Doege-Potter syndrome is a complication of rare tumors. If hy-poglycemia is unexplained, this syndrome should always be suspected, and the presence of un-known masses should be investigated.