Hypoglycemia Due to a Hormone-Secreting Tumor

Figure

a) Axial T2-weighted (T2w) magnetic resonance imaging: extensive pelvic mass (#) and satellite foci (*) encircling the prostate (?), with rectal displacement (?). b) Immunohistochemical staining for insulin-like growth factor 2 (IGF-2) in tumor tissue, 200x magnification: weak but specific expression in tumor cells (*; brownish cytoplasmic signal) in the absence of staining of capsular, non-neoplastic fibroblasts

A 65-year-old male patient presented to the emergency department due to a seizure. Laboratory tests revealed persistent hypoglycemia (down to 2.8 mmol/L; reference: 3.9–5.5) as well as suppressed insulin (<2.8 pmol/L; reference: 18–173) and C-peptide levels (0.09 ng/mL; reference: 0.8–4.2). The patient had a history of a retroperitoneal solitary fibrous tumor (SFT) that had undergone radical resection 6 years earlier. Imaging at our center showed multiple masses in the lesser pelvis encircling the prostate (Figure a). Biopsy confirmed recurrence of SFT. Extensive tumor resection was then performed, with histology demonstrating multiple IGF-2–expressing SFT foci (Figure b). Postoperatively, hypoglycemia resolved completely. Following six additional cycles of chemotherapy with doxorubicin, complete remission was achieved. Solitary fibrous tumor (SFT) is a rare mesenchymal neoplasm with an incidence of approximately 1–2 cases per million population per year. In some cases, paraneoplastic production of insulin-like growth factor-2 (IGF-2) can lead to hormonal activity. From a differential diagnostic perspective, persistent, non-insulin-mediated hypoglycemia should prompt consideration of paraneoplastic hypoglycemia consistent with Doege–Potter syndrome (5–10% of SFT). Complete surgical resection is a key component of treatment.

Dr. med. Philipp Ernst, M.Sc., Klinik für Innere Medizin II, Abteilung für Hämatologie und internistische Onkologie, Universitätsklinikum Jena, Comprehensive Cancer Center Central Germany, Campus Jena, [e-mail]

Dr. med. Bernhard Theis, Institut für Rechtsmedizin, Sektion Pathologie, Universitätsklinikum Jena

Prof. Dr. med. Tobias Franiel, Institut für Diagnostische und Interventionelle Radiologie, Universitätsklinikum Jena

Conflict of interest statement: The authors state that no conflict of interest exists.

Translated from the original German by Christine Rye.

Cite this as: Ernst P, Theis B, Franiel T: Hypoglycemia due to a hormone-secreting tumor. Dtsch Arztebl Int 2026; 123: 352. DOI: 10.3238/arztebl.m2026.0035