Pancreatic fine needle aspiration: to do or not to do?

The aspiration of a pancreatic mass can provide tissue for the diagnosis of a malignancy. Traditionally, computed tomography (CT) and trans-abdominal ultrasonography (US) have been used to guide the aspiration of a pancreatic mass. Recently, endoscopic ultrasound (EUS) has been introduced as an alternative to CT/US guidance because of superior imaging of the pancreas achieved by EUS. The most common technique for tissue acquisition from a pancreatic mass is fine needle aspiration (FNA). The use of a small gauge needle for aspiration cytology of the pancreas has increased the safety and ease of FNA compared to the traditional core tissue biopsy using large gauge needles. The tissue obtained during FNA is evaluated with cytological techniques whereas core tissue specimens are processed for histology. The request for a tissue diagnosis of a pancreatic lesion may originate from a number of specialists caring for the patient. The primary care physician may request a tissue diagnosis in order to aid the patient and family in decision-making. The oncologist often requires a tissue diagnosis in order to provide chemotherapy. The surgeon may need a diagnosis for surgical planning. Lastly, the patient may request a biopsy in order to increase the certainty of a diagnosis. In this presentation, we will review the various techniques for obtaining tissue from a pancreatic lesion and evaluate the advantages and disadvantages. The most common indication for a pancreatic ‘biopsy’ is the need for the documentation of a malignancy in a patient with a malignantappearing pancreatic mass. In patients who are not operative candidates, a large pancreatic mass can be accessed with either cross-sectional imaging, US, or EUS. A tissue diagnosis is particularly important in patients who will be treated with chemotherapy. The cytological analysis of aspirated cytological material can readily differentiate between adenocarcinoma, islet cell malignancies, metastasis to the pancreas, and inflammatory lesions [1]. The result of a pancreatic ‘biopsy’ in operative candidates is important factor in the planning of surgery [2]. For example, the surgical approach to islet cell tumors is often quite different than adenocarcinomas. A more compelling indication for a pancreatic mass ‘biopsy’ is the finding of an atypical pancreatic mass on imaging. The differential diagnosis of an atypical pancreatic mass is often quite wide and includes adenocarcinoma, islet cell tumor, pancreatic metastasis, focal chronic pancreatitis, and cystadenomas. The surgical approach as well as the overall management of the patient will often be altered depending on the results of the pancreatic ‘biopsy’. For example, the management of a serous cystadenoma is quite different than an islet cell tumor.