[Guided fine needle puncture in the diagnosis of pancreatic disorders]

Fine-needle aspiration (FNA) of pancreatic disorders with ultrasound or computed tomographic, and recently echo-endocopic guidance has become commonplace to diagnose the nature of a pancreatic lesion. It is specially usefull in diagnosing solid neoplasms. Most often, FNA is performed to confirm a diagnosis of ductal adenocarcinoma. The aspirate shows cellular clusters with high nuclear-to cytoplasmic ratio, overlapping nuclei and prominant macronucleoli. The cytologic features that permit a diagnosis of neuroendocrin neoplasm are loose cellular aggregates with round nuclei, evently dispersed nuclear chromatin, a moderate amount of amphophilic cytoplasm and rosette formation. Immunocytochemistry can provide additional confirmatory information. Difficulties are encountered in diagnosing cystic neoplasms. The major cytologic differences between serous and mucinous tumors are the absence of mucin and presence of low cuboidal glycogen-containing cells in the microcystic adenoma vs the presence of goblet cells in the mucinous tumors. Except for the presence of necrotic debris, and in the absence of obvious malignant cytologic features, it is impossible to predict the behaviour of mucinous neoplasms. The lower accuracy for cystic neoplasm can be attributed to predominantly bloody specimens and limited cellularity. These problems illustrate the importance of knowing the clinical and radiological features of pancreatic cystic neoplasms.