A subcentimeter duodenal neuroendocrine neoplasm with a liver metastasis upgraded to G3: a case report

Tomoya Kitada,Takashi Ito,Shinji Uemoto,Yosuke Kasai,Yuichiro Uchida,Takamichi Ishii,Satoru Seo,Satoshi Ogiso,Hiroyuki Katsuragawa,Toshihiko Masui

doi:10.1186/s40792-021-01155-1

Abstract

BackgroundAlthough duodenal neuroendocrine neoplasms (DuNENs) usually have indolent phenotypes, some DuNENs exhibit aggressive clinical manifestations. Tumor size > 1 cm, lymph node metastasis, and high grade have been associated with poor prognosis. However, preoperative risk evaluation is often difficult, because Ki-67 index on biopsy is frequently underestimated due to the intratumor heterogeneity. Here, we present a case of a subcentimeter DuNEN with a low Ki-67 index on endoscopic biopsy, who developed lymph node metastasis and high-grade liver metastasis.Case presentationThe patient was a 52-year-old female who presented an epigastric pain. Esophagogastroduodenoscopy revealed a duodenal submucosal lesion with a size of 8 mm. The endoscopic biopsy showed DuNEN with a Ki-67 index of 3.3% (G2 categorized by the World Health Organization 2019 classification). We performed an open partial duodenectomy with adjacent lymph node dissection. Pathological examination of the resected specimens revealed a Ki-67 index of 13.5% (G2) in the “hot spot” and lymph node metastasis. A hepatic low-density area detected on preoperative contrast-enhanced computed tomography appeared to be a liver metastasis on postoperative gadoxetic acid-enhanced magnetic resonance imaging. Subsequently, we performed a laparoscopic partial hepatectomy. Pathological examination of the liver specimen showed a metastatic neuroendocrine tumor with a Ki-67 index of 27.5% (NET-G3). The patient has been alive for 14 months since the hepatectomy.ConclusionsThis case shows the possibility of high malignant potential of DuNEN even if the primary lesion is < 1 cm and has a low Ki-67 index on biopsy.

Highlights

Duodenal neuroendocrine neoplasms (DuNENs) usually have indolent phenotypes, some Duodenal Neuroendocrine neoplasm (NEN) (DuNEN) exhibit aggressive clinical manifestations
This case shows the possibility of high malignant potential of Duodenal NEN (DuNEN) even if the primary lesion is < 1 cm and has a low Ki-67 index on biopsy
We present a case of a subcentimeter DuNEN with a low Ki-67 index on endoscopic biopsy, who developed lymph node metastasis and high-grade liver metastasis

Summary

Background

Neuroendocrine neoplasm (NEN) is a rare disease with an age-adjusted annual incidence of 6.98 per 100,000 population in the United States [1]. Endoscopic biopsy was performed, and the patient was diagnosed as DuNEN with positive chromogranin A and a Ki-67 index of 3.3% [G2 categorized by the World Health Organization (WHO) 2019 classification [7], Fig. 1c–e]. Pathological examination of the liver specimen showed a metastatic neuroendocrine tumor (NET) with well-differentiated morphology and positive chromogranin A and SSTR2 (Fig. 4a–d). Nuclear staining of Ki-67 was much conspicuous in the liver metastasis compared to the primary DuNEN, and the Ki-67 index was calculated as 27.5% (NET-G3, Fig. 4e). The patient was observed without adjuvant therapy, but multiple liver metastases appeared 1 year after the hepatectomy (Fig. 5a–d). Thereafter, she has been managed by medical treatments with everolimus and lanreotide. She has been alive for 14 months since the hepatectomy

Discussion

Conclusions