Needle-Based Confocal Laser Endomicroscopy-Assisted Diagnosis of Acinar Cell Cystadenocarcinoma of the Pancreas

Abstract

Acinar cell carcinoma of the pancreas is a vey rare pancreatic neoplasm. It represents 1-2% of all pancreatic exocrine malignant tumors. We present this rare case of a 79-year-old female with an incidental findings of a pancreatic cyst. The diagnosis of Acinar cell cystadenocarcinoma, a rare variant of acinar cell carcinoma, was made utilizing endoscopic ultrasound with fine needle aspiration (EUS-FNA) with needle based confocal laser endomicroscopy (NCLE). A 79-year-old white female with a past medical history of hypertension, who had multiple admissions to the hospital due to recurrent diverticulitis attacks. CT abdomen and pelvis with contrast showed evidence of diverticulitis with an abscess formation and an incidental findings of a pancreatic cyst. She underwent an EUS that showed a 13 mm by 19 mm cyst in the body of the pancreas. There was a single compartment, thin outer wall and a mural nodule was seen. Needle based confocal laser endomicroscopy (NCLE) was utilized showing atypical cells suggestive of an intraductal papillary mucinous neoplasm. Fine needle aspiration was performed; two passes were made with a 19 gauge needle using a transgastric approach. The pancreatic duct was normal appearance in the entire pancreas. There was no signs of significant pathology in the liver, biliary system, gallbladder, or the ampulla. Further pathology evaluation showed cells were positive for trypsin, and chymotrypsin, and immunohistochemical stain were suggestive of an acinar cystadenocarcinoma, a rare variant of acinar cell carcinoma. Surgical intervention was sought by the patient. Whipple's procedure was intended but due to the extent of the lesion and encasement of surrounding vasculature, curative surgery was not possible. Therefor a biopsy was taken which confirmed the diagnosis and the patient was referred for chemotherapy. Acinar cell cystadenocarcinomas are rare, grossly cystic neoplasms with cytoarchitectural features of acinar cell carcinomas. These lesions are generally slow-growing, and do not cause any significant symptoms. However, as the lesions increase in size they can cause abdominal pain, nausea, vomiting, as well as weight loss. In this case we present an additional modality that assists in the diagnosis and differentiation of the type of pancreatic cysts. NCLE, allows microscopic tissue information in real-time in vivo during EUS-FNA, helping in the differentiation of malignant tumor from normal pancreatic tissue.Figure 1