Ampullary neuroendocrine neoplasms: surgical experience of a rare and challenging entity.

PURPOSE: Ampullary neuroendocrine neoplasms (NENs) account for < 0.3% of gastrointestinal NENs. Surgical options include transduodenal ampullectomy/tumour excision or pancreaticoduodenectomy (PD). We report the experience of two high-volume pancreatic surgical centres of ampullary NENs.

METHODS: Clinical records of patients who underwent surgery for ampullary NENs (January 2007-November 2017) in the study centres were retrieved retrospectively. We evaluated clinical-pathological features, post-operative outcome and follow-up (FU).

RESULTS: Eighteen patients (9 M/9 F, averaging 62 years) were enrolled. All but one were non-functioning NENs; four (22%) patients presented with jaundice. Seven (39%) of the patients underwent ampullectomy/excision (median tumour size 1.5 cm), and 11 (61%) patients underwent PD (median tumour size 2.4 cm). The median operation time of ampullectomy/excision was 221 min with operative blood loss of 75 ml (vs. 506 min and 425 ml in PD). The median hospital stay was 10 days in both groups. Overall surgical morbidity was 33%, due to four biochemical leaks, one pancreatic fistula and one abdominal haemorrhage. No reoperations were needed. The median tumour size was 1.8 (range 0.5-6.7) cm. All G2-G3 NENs were N1 (vs. 1/7 in G1 NENs). Three (17%) cases were mixed exocrine/G3 NECs. After a median FU of 45 (up to 124) months, recurrence occurred in four G3 NEC (31%) patients (median disease-free survival 14 months) after an R0 PD. Disease-related survival was 93, 77 and 66% at 1, 3 and 5 years, respectively.

CONCLUSION: Ampullary NENs are mostly G1-G2 neoplasms. Lymph node metastases rarely occur in G1 NENs < 2 cm in size, which may be treated with ampullectomy/excision. Survival is 66% 5 years after surgery.