Primary hepatic neuroendocrine tumor (NET) or metastatic ileal NET – that is the question

A 65 year old male presented with recurrent epigastric pain, loose stools, flushing of face and breathing difficulty for 1 year. He had undergone right hepatectomy elsewhere for primary hepatic neuroendocrine tumor (NET) 12 years ago. His hematologic and biochemical investigations were within normal range except for raised urine 5 Hydroxyindolacetic acid (HIAA) levels (309 ng/24 hours).

Abdominal contrast enhanced computed tomography studies for liver (triple phase study) and bowel (enterography) were performed. Figure 1 A shows peripheral hyper enhancing lesion in hepatic segment III. Previous right hepatectomy with hypertrophy of remnant liver is noted. There was a markedly enhancing intraluminal polypoidal mass in the ileum (Figure 1 B).

Figure 1. Contrast enhanced computed tomography scan of abdomen

The patient underwent liver mestastatectomy with segmental bowel resection. The 'cut open section' of the resected small bowel revealed a stenosing tumor and a large draining lymph node (Figure 2). Histopathology revealed a well differentiated, intermediate grade NET (WHO; G2). Cytoreductive surgery together with initiation of long acting octreotide analogue resulted in symptomatic control of carcinoid syndrome.

 Figure 2. Segemental ileal resection showing small tumor with large mesenteric lymph node

Primary hepatic NETs are exceedingly rare and such diagnosis should be made only after a thorough clinical and radiological evaluation to exclude an elusive primary elsewhere (usually in the small intestine).¹ Primary ileal NET are often detected late and long term follow up therefore is essential. This is the most likely scenario in the present case also. A revised diagnosis of primary ileal NET with liver metastasis and carcinoid syndrome thus was made.

Aggressive surgery in metastatic NET in the form of removal of small bowel primary together with involved draining lymph nodes is reported to provide significant reduction in tumor related symptoms and improves survival. 

For liver secondaries, even a 70 % cytoreduction by means of parenchyma sparing debulking has been reported to improve progression free and overall survival.² Liver transplantation may be offered to select patients with: well-differentiated NET (Ki-67 <10 %), age <55 years, absence of extrahepatic disease, primary tumor removed before transplantation, stable disease for at least 6 months before LT, and <50% liver involvement.³

 References

1. Fenwick SW, Wyatt JI, Toogood GJ, Lodge JP. Hepatic resection and transplantation for primary carcinoid tumors of the liver. Ann Surg 2004;239(2):210-219.

2. Maxwell JE, Sherman SK, O'Dorisio TM, Bellizzi AM, Howe JR. Liver directed surgery of neuroendocrine metastases: what is the optimal strategy? Surgery 2016;159(1):320-333.

3. Rossi RE, Burroughs AK, Caplin ME. Liver transplantation for unresectable neuroendocrine tumor liver metastases. Ann Surg Oncol 2014;21(7):2398-405.

Authors:

Dr Nitin Vashistha, MS, FIAGES, FACS

Dr Dinesh Singhal, MS, FACS, DNB (Surg Gastro)

Department of Surgical Gastroenterology,
Max Super Speciality Hospital, Saket, New Delhi, India
E mail: gi.cancer.india@gmail.com

www.gicancerindia.com