Management of Small Nonfunctioning Pancreatic Neuroendocrine Neoplasms: Current Opinion and Controversies.

The incidence of small and asymptomatic pancreatic neuroendocrine neoplasms (PNENs) has increased due to the widespread use of high-resolution diagnostic imaging in screening programs. Most PNENs are slow-growing indolent neoplasms. However, a local invasion or metastasis can sometimes occur with PNENs, leading to a poor prognosis. The management of small, nonfunctioning PNENs remains under debate. The National Comprehensive Cancer Network guidelines recommend observation in selected cases of small PNENs less than 2 cm. Pancreatic surgery remains a high-risk operation with a 28-30% morbidity and 1% mortality. Therefore, the decision on how to manage small PNENs is challenging. This review focuses on the management of small nonfunctioning PNENs. We also highlight the malignant potential of small PNENs according to tumor size, tumor grade, and tumor biomarker. Endoscopic-ultrasound-guided biopsy is recommended to evaluate the potential risk of malignancy. Furthermore, we discuss the current guidelines and future directions for the management of small PNENs.

Malignant potential of small pancreatic neuroendocrine neoplasm and its risk factors: A multicenter nationwide study.

BACKGROUND: Pancreatic neuroendocrine neoplasms (PNENs) show heterogeneous biological behavior, and most small PNENs show indolent features. Consequently, selected cases can be considered for observation only, according to the National Comprehensive Cancer Network guideline, however, supporting clinical evidence is lacking. We investigated the clinical course of small PNENs and their risk factors for malignant potential. METHODS: A total of 158 patients with small pathologically confirmed PNENs ≤2 cm in initial imaging were retrospectively enrolled from 14 institutions. The primary outcome was any metastasis or recurrence event during follow-up. RESULTS: The median age was 57 years (range, 22-82 years), and 86 patients (54%) were female. The median tumor size at initial diagnosis was 13 mm (range, 7-20 mm). PNENs were pathologically confirmed by surgery in 137 patients and by EUS-guided fine needle aspiration biopsy (EUS-FNAB) in 21 patients. Eight patients underwent EUS-FNAB followed by surgical resection. The results of WHO grade were available in 150 patients, and revealed 123 grade 1, 25 grade 2, and 2 neuroendocrine carcinomas. A total of 145 patients (92%) underwent surgical resection, and three patients had regional lymph node metastasis. During the entire follow-up of median 45.6 months, 11 metastases or recurrences (7%) occurred. WHO grade 2 (HR 13.97, 95% CI 2.60-75.03, p = 0.002) was the only predictive factor for malignant potential in multivariable analysis. CONCLUSIONS: WHO grade is responsible for the malignant potential of small PNENs ≤2 cm. Thus, EUS-FNAB could be recommended in order to provide early treatment strategies of small PNENs.

Obstructive ileus caused by phlebosclerotic colitis.

A 57-year-old man with chronic kidney disease and a history of using numerous herbal medications visited Inje University Ilsan Paik Hospital for abdominal pain and vomiting. An abdominal radiograph showed diffuse small bowel distension containing multiple air-fluid levels and extensive calcifications along the colon. Computed tomography showed colon wall thickening with diffuse calcification along the colonic mesenteric vein and colonic wall. Colonoscopy, performed without bowel preparation, showed bluish edematous mucosa from the transverse to the distal sigmoid colon, with multiple scar changes. At the mid transverse colon, a stricture was noted and the scope could not pass through. A biopsy of the stricture site revealed nonspecific changes. The patient was diagnosed with phlebosclerotic colitis. After the colonoscopy, the obstructive ileus spontaneously resolved, and the patient was discharged without an operation. Currently, after 2 months of follow-up, the patient has remained asymptomatic. Herein, we report the rare case of an obstructive ileus caused by phlebosclerotic colitis with a colon stricture.