EUS FNA NEUROENDOCRINE TUMORS A. Ginès Endocopy Unit Hospital Cínic. Barcelona (Spain)
GI NEUROENDOCRINE TUMORS GENERAL CONCEPTS Rare neoplasms arising from the neuroendocrine cells of the GI tract Include: carcinoid tumors of the GI wall pancreatic endocrine tumors Sometimes multiple (MEN syndromes) Symptoms depend on the secretion of specific GI hormones Immunohistochemical analysis is crucial for diagnosis Specific therapeutic approach.
GI NEUROENDOCRINE TUMORS Two forms of clinical presentation NON-FUNCTIONING tumors Clinical symptoms related to mass or metastases. Big size To localize the tumor is not the problem A neuroendocrine nature of the tumor is not expected EUS: Resectability FNA
GI NEUROENDOCRINE TUMORS Two forms of clinical presentation FUNCTIONING tumors Clinical symptoms related to hormonal secretion Small size (hormons cause symptoms while tumor is very small) Extrapancreatic or multiple To localize the tumor is the problem Specific image techniques are crucial
Image techniques available in the localization of neuroendocrine tumors each technique has different advantatges and rentability depending on which is the neuroendocrine tumor suspected Conventional techniques Problem Ultrasonography.. low sensitivity Computed Tomography (CT)...... low sensitivity (?) Magnetic Resonance Imaging (RMI)... low sensitivity Endoscopic Ultrasonography (EUS)... high sensitivity Specific techniques expensive, series with small sample size Somatostatin Receptor Scintigraphy (SRS).. location not very precise Selective Angiography + specific substances injection invasive location not very precise Hormonal determinations in portal blood... invasive
Localization of Pancreatic Neuroendocrine Tumors: EUS vs Final Diagnosis All tumors Suspected Suspected (n = 75) Gastrinoma (n=36) Insulinoma (n=36) Sensitivity 93% 100% 88% Specificity 95% 94% 100% PPV 98% 95% 100% NPV 83% 100% 43% Accuracy 93% 97% 89% (Anderson et al, Am J Gastroenterol 2000; 95:2271-7)
Localization of Pancreatic Neuroendocrine Tumors: comparison between EUS and other imaging techniques Technique Patients (n) Correct localization lesions % EUS 19 20/23 86.7 US 19 4/23 17.4 CT 19 7/23 30.4 MRI 8 3/12 25 Angiography 11 4/15 26.6 SRS 9 2/13 15.4 (De Angelis et al, Eur J Ultrasound 1999; 10:139-150)
GI NEUROENDOCRINE TUMORS ROLE OF EUS High accuracy for localization of the tumor Important to rule out multiple tumors and therefore to plan management and surgical approach Crucial if endoscopic treatment is an option Why EUS-FNA?
EUS-FNA in NEUROENDOCRINE TUMORS Is it necessary? In favour : Tissue diagnosis is always desirable: DD with lymph node Risk of seading is low Some patients want to know May be important in patients with more than one lesion Possibility of diseases with different therapeutic approach: M1, limfoma Against: It may not affect management
M1 SA T SV T
EUS-FNA in NEUROENDOCRINE TUMORS Cytological evaluation of the samples Cytomorphological criteria Well-differentiated Uniform and monotonous cells Plasmacytoid appearance Finely stippled and uniformlly distributed chromatin Poorly differentiated Similar to carcinomas or lymphoma (small-cell pancreatic carc.)
EUS-FNA in NEUROENDOCRINE TUMORS Cytological evaluation of the samples Differential diagnosis of well-differentiated neuroendocrine tumors Acinar cells of normal pancreas Plasmocitoma Solid pseudopapillary tumor Immunocytological stains Endocrine tumor Acinar cells of normal pancreas
EUS-FNA in NEUROENDOCRINE TUMORS Immunocytochemical stains in cell block preparation Antibodies against CD56 Neurone-specific enolase Synaptophysin Chromogranin A Chromogranin +
EUS-FNA in NEUROENDOCRINE TUMORS Cell block smear Cromogranin + Importance of cell block for immunocytochemical analysis!!!
EUS-FNA in NEUROENDOCRINE TUMORS EUS is the most accurate technique to localize the GI neuroendocrine tumors EUS FNA : Only mandatory if it may change the therapeutic approach Differential diagnosis with lymph node Need for immuncytochemical analysis (sample must be good enough)
EUS-FNA in NEUROENDOCRINE TUMORS Perform EUS FNA when the DD with a lymph node is raised or if the result may change treatment Take additional passes for immunocytological assessment