Endoscopic ultrasound-guided fine needle injection of alcohol for ablation of an insulinoma: a well documented successful procedure

A 21-year-old woman presented with recurrent hypoglycemia, syncope, and episodic seizures, associated with rapid weight gain (body mass index [BMI] 60). Hyperinsulinemia was confirmed and she was started on treatment with diazoxide. Magnetic resonance imaging showed a 1.5-cm nodule at the pancreatic head. Endoscopic ultrasound (EUS) confirmed a 1.5-cm hyperechoic nodule within the pancreatic head, between the common bile duct and the main pancreatic duct. EUS-guided fine needle aspiration (EUS-FNA) was performed with a 22-gauge needle (Echo-Tip; Cook Medical, Limerick, Ireland) ([Fig. 1]) and the definitive diagnosis of an insulinoma was established by immunohistochemical analysis ([Fig. 2]).

Fig. 1 Echoendoscopic image showing the endoscopic ultrasound-guided fine needle aspiration.

Fig. 2 Histological analysis of the fine needle aspirate showing the appearance on: a hematoxylin and eosin (H&E) staining; b – e immunohistochemical staining with: b CD 56; c insulin; d Ki 67; e synaptophysin.

Surgical treatment (Whipple’s procedure) was contraindicated because of the patient’s high BMI. Therefore, EUS-guided fine needle injection (EUS-FNI) was suggested to ablate the lesion. The patient was hospitalized for prior hyper-hydration. EUS-FNI was performed with 99 % ethanol (1.5 mL) using a 22-gauge needle (Echo-Tip), with the patient under general anesthesia. After 60 seconds, ultrasound monitoring showed the typical image of a hyperechogenic shadow forming from within the lesion. No portal vein thrombosis was detected on EUS after the alcohol injection ([Video 1]) and there was no evidence of acute pancreatitis after 2 days of in-hospital observation. At follow-up 2 weeks after discharge, the patient’s serum glucose had returned to normal levels, she had lost 4 kg and the diazoxide dose was reduced.

Video 1 Endoscopic ultrasound-guided fine needle injection (EUS-FNI) of 99 % ethanol into an insulinoma.

Pancreatic neuroendocrine tumors (pNETs) account for 1 % – 2 % of all pancreatic tumors⁠. PNETs are classified as either functional or nonfunctional, the latter being more common (up to 85 %). Among functional pNETs, insulinomas are the most common [1] [2]. EUS is a useful diagnostic tool, showing a sensitivity of up to 85 % [3]. Insulinoma resection was first reported in 1929 and remains the treatment of choice [4]. Nevertheless, EUS-FNI of ethanol into an insulinoma has been described as an efficient and safe technique for hypoglycemia resolution, and is indicated for patients with a prohibitive surgical risk [5].

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• References

• 1 Dasari A, Shen C, Halperin D. et al. Trends in the incidence, prevalence, and survival outcomes in patients with neuroendocrine tumors in the United States. JAMA Oncol 2017; 3: 1335-1342
• 2 Kasumova GG, Tabatabaie O, Eskander MF. et al. National rise of primary pancreatic carcinoid tumors: comparison to functional and nonfunctional pancreatic neuroendocrine tumors. J Am Coll Surg 2017; 224: 1057-1064
• 3 Placzkowski KA, Vella A, Thompson GB. et al. Secular trends in the presentation and management of functioning insulinoma at the Mayo Clinic, 1987 – 2007. J Clin Endocrinol Metab 2009; 94: 1069-1073
• 4 Howland G, Campbell WR, Maltby EJ. et al. Dysinsulinism: Convulsions and coma due to islet cell tumor of the pancreas, with operation and cure. J Am Med Assoc 1929; 93: 674-679
• 5 Levy MJ, Thompson GB, Topazian MD. et al. US-guided ethanol ablation of insulinomas: a new treatment option. Gastrointest Endosc 2012; 75: 200-206