Pancreatic cysts

Abstract

Preoperative diagnosis of pancreatic cysts benefits from integrating the clinical, radiological, and cytological features. As patient management algorithms evolve to increasingly nonsurgical options, accuracy in distinguishing mucinous from nonmucinous and benign from malignant mucinous cysts is important. This review focuses on pseudocysts, serous cystadenomas, intraductal papillary mucinous neoplasms (IPMNs), and mucinous cystic neoplasms. Patients with pseudocysts almost always present with pancreatitis and are usually medically managed. Radiological studies reveal a unilocular cyst mostly in the pancreatic tail. Cyst fluid is thin, with high amylase but low carcinoembryonic antigen (CEA) levels. DNA mutations are absent. Serous cystadenomas are benign and do not require resection. Patients are usually asymptomatic and have microcystic or macrocystic masses anywhere in the pancreas. Cytology is frequently nondiagnostic. CEA and amylase levels are low. DNA analysis may reveal loss of heterozygosity (LOH) at 3p if associated with Von Hippel-Lindau disease. Neoplastic mucinous cysts are highly variable in their presentation. Most are resected. Mucinous cystic neoplasms typically arise in the body or tail of the pancreas of middle-aged women and demonstrate a septated cyst without dilatation of the main pancreatic duct. Branch duct IPMNs are more common in the pancreatic head of elderly men. Main duct dilatation correlates with main duct or combined type IPMN. Both types of mucinous cysts produce variable amounts of mucin. Cytologically nonmalignant but atypical epithelial cells, even when scant, are an indication of a high risk for malignancy. High CEA level supports a mucinous cyst, as do KRAS mutation and good quality DNA levels. KRAS mutation and multiple LOH support malignancy.

Elevated microRNA miR-21 Levels in Pancreatic Cyst Fluid Are Predictive of Mucinous Precursor Lesions of Ductal Adenocarcinoma

“…For example, the diagnostic value of the tumor-specific antigens secreted by the neoplastic epithelium, such as carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 and cancer antigen 125, has been analyzed in numerous studies [42,43,44,45]. Of these, cyst fluid CEA appears to have the most promising performance criteria so far in distinguishing mucinous from nonmucinous cystic lesions of the pancreas.…”

“…In addition to imaging, aspiration of cyst fluid contents can be conveniently and safely performed by EUS-guided fine-needle aspiration, which provides material for cytopathology and the assessment of tumor markers. Unfortunately cystic lesions, in general, are fairly hypocellular, such that the sensitivity of cytology examination remains low (∼50%) despite a high specificity [20,21,22]. Thus, there is an unmet need for ancillary biomarkers in cyst fluid material that can provide additional and reliable distinction between mucinous cystic precursors of pancreatic cancer versus clinically insignificant nonmucinous lesions.…”

EUS–FNA of Brunner’s gland hamartoma: a case report

“…In cases with scant cellularity or small volume of aspirated fluid, it has been reported that molecular analyses (Kras mutation, more than two LOH) are supportive of the diagnosis of neoplastic (mucinous) cystic lesion. 9 Other low-grade mucinous cystic neoplasms (MCN) usually have scant cellularity and single cells or small clusters of cells with basally placed nuclei and cytoplasmic mucin. A recently described mucinous non-neoplastic cyst (MNC), not a well-recognized entity, also shares many clinical and radiological features with MCN and IPMN and may resemble BGH.…”

Can outcome of pancreatic pseudocysts be predicted? Proposal for a new scoring system

“…[17][18][19] Cyst fluid may contain acute and chronic inflammatory cells, histiocytes, and macrophages. [20] Only complicated cases with gastrointestinal epithelial and mucin contamination, particularly from the stomach, should include cystic lining epithelial cells. [19,21,22] Van der Waaij et al analyzed 12 studies and demonstrated that CEA levels below 5 ng/mL present a specificity of 95% for pseudocyst formation.…”