The Use of Fine Needle Aspiration Cytology for the Distinction of Pancreatic Mucinous Neoplasia

Abstract

Cytology frequently has some role in preoperatively distinguishing pancreatic mucus-producing neoplasia (intraductal papillary mucinous neoplasms [IPMNs] and mucinous cystic neoplasms [MCNs]) from other pancreatic cysts. We evaluated all cytologic specimens at our institutions from resected pancreatic cystic lesions for lesional extracellular and cellular material. Lesional extracellular material was identified in 32 of 38 of the cytologic samples from cystic pancreatic mucus-producing neoplasms (28 of 31 IPMNs and 4 of 7 MCNs). Lesional cellular material was seen in 22 of 38 cases (17 of 31 IPMNs and 5 of 7 MCNs). Lesional material was more commonly identified in higher grade and invasive lesions. Lesional extracellular material was seen in 3 of 14 samples of other pancreatic cysts, and lesional cellular material was seen in 6 of 14 cases.

Cyst Wall Puncture and Aspiration During EUS-guided Fine Needle Aspiration May Increase the Diagnostic Yield of Mucinous Cysts of the Pancreas

“…In our study, 77% of the specimens had epithelium adequate for interpretation, which was higher than has previously been reported for standard FNA. 23 There have been only a few other reports of alternate methods for sampling the cyst wall itself during EUS-FNA to achieve higher diagnostic yields. One study, for example, used a larger caliber biopsy needle ("trucut") to obtain a core biopsy of the cyst wall in 10 patients and showed a diagnostic accuracy of 70% compared with 0% for cyst fluid cytology.…”

Precursor Lesions of Pancreatic Cancer

“…Characteristic cytological features of IPMNs are extracellular mucin and papillary clusters of mucinous epithelium with a variable degree of atypia [48,49,50]. Features suggesting high-grade IPMN include papillary clusters and loss of honeycomb structures with coarse chromatin, irregular nuclear membrane, and high nuclear-to-cytoplasmic ratio [49].…”

Classification, Morphology, Molecular Pathogenesis, and Outcome of Premalignant Lesions of the Pancreas

“…The hallmark feature in cytology for a neoplastic mucinproducing cyst (either MCN or IPMN) includes the presence of thick extracellular mucin (neoplastic mucin; Figure 1, a). 11, 12 Stelow et al 13 reviewed the fine-needle aspirations of 31 IPMNs and found extracellular mucin in a majority of these lesions. Other cytologic features for IPMN (and MCN) include mucinous glandular epithelial cells in groups, papillary clusters, single cells with varying degrees of cytologic atypia, and cyst debris (Figure 1, b).…”