Figure 2: Imaging of the intrathoracic SFT before redebulking surgeryA coronal chest-CT showing a large heterogeneous tumor mass infiltrating the mediastinum, pleura, pericardium and diaphragm. In addition, the expansion of the left lung is significantly reduced. B and C: Transversal fusion (B) and maximum intensity projection (C) of [68Ga]DOTATATE/PET-CT showing the SFT and further lesions in the pericardial fat tissue with variable and focally increased SSTR-expression.
From the first day after her admission, the patient required continuous intravenous glucose infusions (intravenous glucose 20% with infusion rates of up to 40 ml/hour) overnight, in order to prevent fatal hypoglycemic episodes. Since the tumor showed SSTR-expressing lesions in [68Ga]DOTATATE/PET-CT, an adjuvant treatment with a somatostatin-analogue, Octreotide, was started. While uptitration of Octreotide to a dose of 800 µg/day subcutaneously (4 x 200 µg) improved hypoglycemic episodes, continuous glucose infusions were still necessary to maintain tolerable blood glucose levels above 50 mg/dl (2.8 mmol/l) (Figure 3).
After weighing the potential age-related risks and benefits, with informed consent of the patient, another debulking surgery was performed, removing great portions of the gelatinous, liquified tumor by suction and manual extirpation. Histological examination of the resected tissue again confirmed the diagnosis of the SFT, with fusiform neoplasia, elevated mitosis rates (5 per HPF) and without necrosis. Immunohistology showed that tumor cells were CD34(+), STAT6(+), EMA(-), CK1/3(-), and SMA(-), with a MIB-1 determined proliferation rate of 15%. According to Demicco et al 2017 [22], the tumor was classified as low risk. Glucose infusions could be terminated immediately after the surgery. Due to the inability to achieve R0 resection and the rapid tumor progression after her initial debulking surgery, the patient continued on Octreotide-treatment aiming at a suppression of tumor proliferation and a reduction of hypoglycemic episodes in the future with now reduced tumor mass. Ten days after surgery Octreotide was replaced with Lanreotide (120 mg/month subcutaneously) to allow a longer interval between injections. After the first application of Lanreotide the patient was discharged. No hypoglycemic episodes have been reported since the redebulking surgery (Figure 5)