Non-islet-cell tumour hypoglycaemia (NICTH): About a series of 6 cases

Abstract

The purpose of this study was to analyse the characteristics of 6 patients managed in a university hospital between 1996 and 2016 for non-islet cell tumor hypoglycemia (NICTH), a form of hypoglycaemia due to the paraneoplastic secretion of IGF-2 or its related substances. ResultsThree of these 6 patients (50%), aged over 69 years, including 2 with acromegaloid phenotype, presented with a pleural solitary fibrous tumor (SFT), with median diameter 20 cm (interquartile range, 12.5–20.5) with a low median SUV (3.3 g/mL (QR, 2–7.5)) on 18F-FDG PET. The other 3 patients presented respectively neuroendocrine carcinoma (NEC) of the palate (70-year-old woman), retroperitoneal myxofibrosarcoma (66-year-old man) and meningeal hemangiopericytoma (36-year-old woman). All 3 were inoperable and did not respond to any therapy other than glucose solution. Corticosteroid therapy was effective in the 3 SFTs and the NEC. One of the SFTs recurred 10 years later with asymptomatic hypoglycemia, which resolved after reintervention. Median (IQR) blood glucose levels of the 6 patients was 0.4g/L (QR, 0.31–0.41), with hypoinsulinemia at 0.7mIU/L (QR 0.7–2.0), undetectable GH, low IGF-1, normal IGF-2 level in 5/6 cases, a high IGF-2:IGF-1 ratio at 26.9 (QR, 20.8–37.8), hypokalemia and hypomagnesemia. ConclusionNICTH is a rare syndrome, which should be considered in the presence of hypoinsulinemic hypoglycemia with low GH and IGF-1, and a IGF-2:IGF-1 ratio>10. Corticosteroid therapy was effective in elderly subjects, particularly with solitary fibrous tumor, which was generally operable. Hemangiopericytoma and myxofibrosarcoma had poor prognosis in younger patients.