Approach to pancreatic cystic lesions

Pancreatic mucinous cystadenocarcinoma: Epidemiology and outcomes

BACKGROUND

Pancreatic mucinous cystadenocarcinoma is a rare malignancy. Our aim was to investigate the demographic, pathological characteristics, treatment modalities and survival of patients with mucinous cystadenocarcinoma via the National Cancer Institute's Surveillance Epidemiology and End Results (SEER) database analysis.

MATERIALS AND METHODS

This was a retrospective study of SEER database's records on patients with mucinous cystadenocarcinoma diagnosed from 1988 to 2012. Primary outcome measures were clinico-pathological characteristics, observed and disease-specific survival.

RESULTS

A total of 507 patients were identified. Median age at diagnosis was 67 years and most patients were female (68.4%). The tumors were mainly low grade (82.9%, grade I-II) and frequently localized (42.8%) in the body/tail of the pancreas (45.6%). According to Kaplan-Meier curves observed survival was 111 months (95%CI: 82.5, 139.5) vs 14 months (95% CI: 10.9, 17.1) vs 4 months (95%CI: 2.9, 5.1) for patients with localized, regional and distant disease, respectively. One-year disease-specific survival for patients with localized disease was 90.1%, vs. 56.7% for those with regional and 18.7% with distant tumor spread.

CONCLUSIONS

Mucinous cystadenocarcinomas tend to be low grade tumors, localized to the pancreatic body/tail. Surgery as the primary therapeutic intervention and tumor stage are independent predictors of disease-specific survival.

Endoscopic ultrasound-guided fine-needle aspiration for the diagnosis of pancreatic cysts by combined cytopathology and cystic content analysis

Recent advances in imaging technology have resulted in an increase in incidental discoveries of pancreatic cystic lesions. Pancreatic cysts comprise a wide variety of lesions and include non-neoplastic cysts and neoplastic cysts. Because some pancreatic cysts have more of a malignant potential than others, it is absolutely essential that an accurate diagnosis is rendered so that effective care can be given to each patient. In many centers, endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) has emerged as the modality of choice that enables one to distinguish between mucinous and non-mucinous lesion, diagnose malignancy and collect cyst fluid for further diagnostic studies, such as pancreatic enzyme levels, molecular analysis and other tumor biomarkers. The current review will focus on EUS-guided FNA and the cytological diagnosis for pancreatic cysts.

Diagnosis and management of cystic lesions of the pancreas

Pancreatic cystic lesions (PCLs) are being increasingly identified in recent years. They show a wide spectrum of imaging and clinical features. The diagnosis and discrimination of these lesions are very important because of the risk for concurrent or later development of malignancy. PCLs are usually first diagnosed and characterized by conventional imaging modalities such as trans-abdominal ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI). However, their ability to differentiate the benign and malignant lesions remains limited. Endoscopic US may be more helpful for the diagnosis and differentiation of PCLs because of its high resolution and better imaging characteristics than cross-sectional imaging modalities. It also allows for fine-needle aspiration (FNA) of cystic lesions for biochemical, cytological and DNA analysis that might be further helpful for diagnosis and differentiation. The management options of PCLs are to observe, endoscopic treatment or surgical resection. However, the decision for management is sometimes hampered by limitations in current diagnostic and tissue sampling techniques. As further diagnostic and non-invasive management options become available, clinical decision-making will become much easier for these lesions.

False-negative rate of endoscopic ultrasound-guided fine-needle aspiration for pancreatic solid and cystic lesions with matched surgical resections as the gold standard: one institution's experience

BACKGROUND

The diagnosis of pancreatic tumors is often complicated because of sampling and interpretive challenges. The current study was performed to determine the rates, types, and causes of diagnostic discrepancies.

METHODS

The authors retrospectively reviewed cytology cases from 2004 to 2010 using matched surgical resection cases as the gold standard.

RESULTS

A total of 733 cases were divided into 3 categories: 1) positive or suspicious (290 cases); 2) negative or atypical (403 cases); and 3) unsatisfactory (40 cases). Of these cases, 101 fine-needle aspiration (FNA) cases had matched surgical resections including 58 positive diagnoses, 39 negative diagnoses, and 4 unsatisfactory diagnoses. All 19 discrepant cases represented false-negative diagnoses without any false-positive cases noted, which included 2 cases with interpretive errors (10%) and 17 cases with sampling errors (90%). All matched cytology cases were divided into 5 subgroups based on the type of lesion or type of error and were analyzed for sensitivity and specificity. The sampling error rate in cystic lesions (8 of 24; 33%) was significantly higher than that in solid lesions (9 of 73; 12%). The false-negative rate in the interpretive error group (3%) was significantly lower than that in the sampling error group (23%).

CONCLUSIONS

The results of the current study confirm that pancreatic endoscopic ultrasound-guided FNA diagnosis has a very low false-positive rate but a relatively high false-negative rate using matched surgical resections as the gold standard. The major cause of a false-negative cytology diagnosis is sampling error and the rate of sampling error in cystic lesions is significantly higher than that in solid lesions.

[Pancreatic tumors]

The management of pancreatic cancer is complex and prognosis is poor. The etiopathogenesis of pancreatic cancer has been related to several factors, such as diabetes mellitus, smoking and alcohol use, the presence of pancreatic cystic lesions and distinct genetic syndromes. Among the diagnostic options, endoscopic ultrasound (EUS) continues to be developed, with the use of elastography, contrast agents and EUS-guided aspiration and the application of technical improvements that increase diagnostic efficacy (such as the use of specific stains, new aspiration needles, etc.). New biomarkers are also being sought that would help in differential diagnosis, such as M2PK, adiponectin, and Reg4. Among prognostic factors, the importance of nodal involvement and study of surgical resection margins has been confirmed. The role of individual predisposition in determining response to specific treatments continues to be investigated. Research also continues into the development of EUS-guided injection of therapeutic substances and the role of oncological treatment, with new data on the utility of gemcitabine and of statins as mediators of angiogenic suppression or of high-dose vitamin C with cytotoxic effects. Notable in the field of palliative treatment is the development of new biliary stents that aim to reduce obstruction rates. The development of EUS and EUS-guided fine-needle aspiration has been crucial in cystic pancreatic tumors, especially in distinguishing benign from malignant lesions or those with potential for malignant transformation (presence of mural modules, dilatation of the main pancreatic duct, the presence of masses, CEA levels, etc.). The characteristics of these tumors must be determined to evaluate whether surgery or conservative management is the best therapeutic option.