Performance of endoscopic ultrasound-guided fine needle aspiration in diagnosing pancreatic neuroendocrine tumors

Abstract

Background:Pancreatic neuroendocrine tumors (PNETs) are rare tumors of the pancreas, which are increasingly diagnosed by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). In this retrospective study, we assessed the performance of EUS-FNA in diagnosing PNETs.Materials and Methods:We identified 48 cases of surgically resected PNETs in which pre-operative EUS-FNA was performed. The clinical features, cytological diagnoses, and surgical follow-up were retrospectively reviewed. The diagnostic performance of EUS-FNA was analyzed as compared to the diagnosis in the follow-up. The cases with discrepancies between cytological diagnosis and surgical follow-up were analyzed and diagnostic pitfalls in discrepant cases were discussed.Results:The patients were 20 male and 28 female with ages ranging from 15 years to 81 years (mean 57 years). The tumors were solid and cystic in 41 and 7 cases, respectively, with sizes ranging from 0.5 cm to 11 cm (mean 2.7 cm). Based on cytomorphologic features and adjunct immunocytochemistry results, when performed, 38 patients (79%) were diagnosed with PNET, while a diagnosis of suspicious for PNET or a diagnosis of neoplasm with differential diagnosis including PNET was rendered in the 3 patients (6%). One case was diagnosed as mucinous cystic neoplasm (2%). The remaining 6 patients (13%) had non-diagnostic, negative or atypical diagnosis.Conclusions:Our data demonstrated that EUS-FNA has a relatively high sensitivity for diagnosing PNETs. Lack of additional materials for immunocytochemical studies could lead to a less definite diagnosis. Non-diagnostic or false negative FNA diagnosis can be seen in a limited number of cases, especially in those small sized tumors.

Diagnostic Performance of Endoscopic Ultrasound (EUS)/ Endoscopic Ultrasound – Fine Needle Aspiration (EUS-FNA) Cytology in Solid and Cystic Pancreatic Neuroendocrine Tumours

“…Previous studies have reported a EUS-FNA sensitivity between 80% and 90% [6,[11][12][13].The cytological yield in our series improved from 59% between 2003 and 2007 to 80.7% between 2008 and 2011. The improvement in our figures is possibly due a combination of the following factors: increased awareness among endosonographers and cytopathologists, use of LBC for processing and increasing the number of categorical diagnosis by reducing the number of samples categorised as atypical or suspicious [21][22][23].…”

Metastatic neoplasms to the pancreas diagnosed by fine‐needle aspiration/biopsy cytology: A 15‐year retrospective analysis

“…In addition, both tumors may form true rosettes or pseudorosettes . In contrast, the classic salt‐and‐pepper chromatin pattern of pancreatic neuroendocrine tumor is not a common feature of olfactory neuroblastoma, whereas neurofibrillary matrix has not been observed in the former . Well‐differentiated pancreatic neuroendocrine neoplasms may stain positively for synaptophysin, chromogranin A (Figure E), and CD56 (Figure C) .…”

“…The differential diagnosis should include well‐differentiated pancreatic neuroendocrine tumors. Similar to olfactory neuroblastoma, they may appear as a monomorphic population of dispersed or loosely cohesive tumor cells with scant cytoplasm . In addition, both tumors may form true rosettes or pseudorosettes .…”

“…Similar to olfactory neuroblastoma, they may appear as a monomorphic population of dispersed or loosely cohesive tumor cells with scant cytoplasm . In addition, both tumors may form true rosettes or pseudorosettes . In contrast, the classic salt‐and‐pepper chromatin pattern of pancreatic neuroendocrine tumor is not a common feature of olfactory neuroblastoma, whereas neurofibrillary matrix has not been observed in the former .…”

Fine-Needle Aspiration Cytology in the Diagnosis of Pancreatic Neuroendocrine Tumors: A Single-Center Experience of 25 Cases

“…Samples can be taken using a variety of image-guided techniques, including endoscopic retrograde cholangiopancreatography, transabdominal ultrasound (US) and computed tomography (CT) [11,12]. However, endoscopic US-guided FNA (EUS-FNA) is the modality most commonly employed today to sample pancreatic lesions and has the potential to make a diagnosis in lesions as small as 5 mm in the pancreatic head and body with a sensitivity greater than 85% [12,13]. Overall, the sensitivity of EUS-FNA ranges between 80 and 90%, with specificity approaching 100% [13,14].…”