Pancreatic cystic lesions without overt cytologic atypia: Proposed diagnostic categories for endoscopic ultrasound-guided fine-needle aspiration cytology with utilization of fluid carcinoembryonic antigen level

Objectives: It was the aim of this study to examine pancreatic cyst cases that lack markedly atypical or malignant epithelium on endoscopic ultrasound-guided fine-needle aspirations. Study Design: We conducted a retrospective case review study, including 24 cases that were either acellular or lacked cytologic atypia and were subsequently resected. The cases were retrospectively divided into 3 categories: (1) non-diagnostic, (2) cyst contents only, and (3) cyst contents with bland-appearing epithelium. The cyst contents were subdivided into mucinous and non-mucinous types. The cytologic diagnoses were correlated with cyst fluid carcinoembryonic antigen (CEA) levels and subsequent histologic diagnoses. Results: Category 1 comprised 4 cases: 2 cases (CEA >800 ng/ml) with mucin-producing neoplasms and 2 cases (CEA not determined) with microcystic serous cystadenomas. Category 2 included 4 cases with non-mucinous and 4 with mucinous contents. In the first subgroup, 2 cases (CEA >800 ng/ml) showed mucinous cystic neoplasms and 2 cases (CEA negligible or not determined) pseudocysts. In the second subgroup, there were 3 cases with neoplastic mucinous cysts (1 CEA >800 ng/ml, 2 not determined) and 1 case with a lymphoepithelial cyst with mucinous metaplasia (CEA >800 ng/ml). Almost all cases (10/11) in category 3 had neoplastic mucinous cysts regardless of the CEA levels. Conclusions: The proposed 3 cytologic categories of pancreatic cystic lesion combined with cyst fluid CEA levels provide useful clinical information.