2932 Histological Diagnosis of Pancreatic Serous Cystadenomas Using a 22G Core Biopsy Needle: A Case Series

Abstract

INTRODUCTION: Pancreatic Serous Cystadenoma or Pancreatic Cystic Serous Neoplasm (SCN) are a type of benign pancreatic tumor that account for 1-2% of all pancreatic masses. They are most often benign, with very rare malignant potential. SCN's will often have a cystic or honeycomb appearance on CT scan. In the past, the mainstay of diagnosing SCN has been via endoscopy ultrasound (EUS) with fine needle aspiration (FNA) to assess fluid for CEA levels and also for cytological analysis. However fluid can be difficult to obtain and often there is not enough cellularity for cytology. In this case series of 7 patients we performed fine needle biopsy (FNB) of the cell walls of pancreatic cysts as a technique for histological review. METHODS: We retrospectively reviewed medical records of patients who underwent EUS for FNA for fluid sampling of pancreatic cysts but due to microcystic nature a decision was made to proceed with FNB to obtain tissue for histology. FNB was done using 22 G FNB needle with slow stylet pull technique. The tissue was placed in formalin for histological analysis by an expert GI pathologist. RESULTS: A total of seven patients were evaluated. The mean age was 75 years old and 5 of the patients were female. All patients had one cyst that was sampled. The location of the cyst was on the head in 1 of the patients and body or tail of the other 6 patients. The mean cyst size was 31.1 mm (range 14-40 mm). There were no post procedure complications. All seven samples were adequate for histological analysis. Six out of the seven biopsy samples were consistent with serous cystadenomas. One samples showed benign pancreatic acinar tissue and stroma without malignancy. CONCLUSION: Management of pancreatic SCNs can be challenging as no follow up is recommended if the diagnosis is confirmed but lots of times a definite diagnosis cannot be made based on endosonographic and CT/MRI findings. These patients can be potentially subject to repeat imaging for surveillance. Here we show that pursuing FNB instead of FNA for microcystic lesions can yield enough tissue for histological diagnosis of SCNs and can alter management and avoid further imaging.