SUN-114 Successful Long-Term Medical Management of Insulinomas

Abstract Background: Insulinomas are usually benign, solitary tumors. Surgical resection is the treatment of choice and only method of cure. Surgical cure is not possible with unresectable metastatic disease, unlocalizable disease, or contraindications to surgery. Long-term medical management may be required. Clinical Cases: Patient 1: A 57-year-old female was diagnosed at age 42 when imaging confirmed a 2.4cm insulinoma in the pancreatic tail and two lesions in the right hepatic lobe. She underwent distal pancreatectomy with splenectomy, and hepatic wedge resection. Follow-up imaging showed two new hepatic lesions. She underwent chemoembolization with resolution of her symptoms. By age 48, her symptoms returned. Imaging showed new lesions in the liver, not amenable to embolization. She was placed on Octreotide 20mg IM monthly and her symptoms resolved soon after initiation of therapy. She has since had an unremarkable clinical course. Additional therapies have been deferred as follow-up imaging has not shown disease progression. Patient 2: A 48-year-old female was diagnosed at age 37. CT and MRI did not find a source. A DOPA-PET showed increased uptake in head and tail of the pancreas. An 8-hour ex-laparotomy with EUS and palpation of the pancreas did not localize a mass. A second surgery, with 75% removal of the distal pancreas, including the tail and body, did not relieve her symptoms. She had unsuccessful trials of verapamil, verapamil with low-dose diazoxide, and octreotide. She started diazoxide 300mg daily, but had fluid retention and tachycardia. Her dose was decreased to 200mg daily and HCTZ 25mg daily was started. Due to persistent symptoms, prednisone was started at 5mg in the morning and 2.5mg in the afternoon, which gave symptom relief. At her request it was decreased to 5mg daily. By age 42 she had self-decreased it to 2.5 mg daily, but continued her other meds. She endorsed the return of symptoms, but felt she could manage them without increasing her dose. At age 44, as part of a clinical trial, an MRI and nuclear medicine study showed a 9mm lesion in the head of the pancreas. Another exploratory surgery did not find a lesion. Currently, she is on the same medication regiment with strict diet and frequent meals. She endorses only rare hypoglycemic episodes. Conclusion: The patients have been managed with medical therapy for 15 and 11 years respectively. Long-term survival data of patients with metastatic insulinoma indicates that prolonged survival is unlikely; however, most data is from the 1990s or earlier. It does not incorporate new medical treatments, or advancements in technology and the field of medicine. Patients who are not candidates for surgical cure, may have better survival rates and undergo longer courses of medical management. Additionally, while oral prednisone is not standard therapy for insulinoma, there are cases of its use to control hypoglycemia when other treatments are exhausted.