Is There a Relationship Between Tuberous Sclerosis Complex and Insulinoma?

Tuberous sclerosis complex (TSC) is an inherited neurocutaneous disease characterized by multiple hamartomas in multiple organs. However, there is limited evidence about neuroendocrine tumors (NETs) in patients with TSC, and routine screening of NETs is not recommended in the guidelines. Insulinomas are also an extremely rare disease. According to our knowledge, we presented the 10th TSC patient diagnosed with insulinoma in the literature. Thirty-two years old male patient diagnosed with TSC at the age of 27 due to typical skin findings, renal angiomyolipoma, history of infantile seizures, and cranial involvement was referred to our clinic. The main symptoms of the patient were palpitations, diaphoresis, confusion, and symptoms were improved after consuming sugary foods. Seventy-two hours fasting test was performed, and a low glucose level at 41 mg/dl, a high insülin level at 21.65 µIU/mL, and a high C-peptide level at 7.04 ng/mL were found at the 8th hour. In addition, a 12x7 mm lesion in the pancreatic tail was detected in abdominal imaging. Ga-68 PET-CT (gallium-68 positron emission tomography-computed tomography) detected an increased uptake of Ga-68 in the pancreatic tail. The patient underwent distal pancreatectomy, and pathological evaluation was consistent with an insulinoma. The patient's symptoms improved postoperatively. Since in nearly all TSC cases, as in our case, neuropsychiatric abnormalities, such as epilepsy, are one of the main disease manifestations, and these symptoms may be confused with the clinical manifestations of hypoglycemia in insulinoma. Therefore, patients with newly developed neurological symptoms and behavioral defects should be evaluated in terms of insulinoma.