Non-Neoplastic and Neoplastic Cysts of the Pancreas.

Inflammatory, developmental, and neoplastic lesions may all present as cystic masses on imaging. Pseudocyst is the most common of these and presents in association with a history of pancreatitis. Pancreatic cystic neoplasms are uncommon compared to solid neoplasms. They often present incidentally; therefore, an incidentally discovered cyst in the pancreas should be assessed with a high index of suspicion for neoplasm. The most common and frequently encountered cystic neoplasms include serous cystadenoma, mucinous cystic neoplasm, and intraductal papillary mucinous neoplasm. Less common epithelial cystic neoplasms include acinar cell cystadenoma and cystadenocarcinoma. Any solid neoplasm occurring in the pancreas or vicinity of the pancreas that has undergone cystic degeneration may present as a cystic mass. Non-epithelial lesions, such as lymphangioma, are also included in the differential diagnosis. The work-up needs to begin with a review of the clinical and imaging findings to establish a differential diagnosis. The primary focus of the pathologist will be first on differentiating mucinous from non-mucinous entities, since this will determine if the mass is an intraductal papillary mucinous neoplasm or a mucinous cystic neoplasm. If it is mucinous, the next step is to determine if the cystic neoplasm contains cells with high-grade cytological features. If it is non-mucinous, the pathologist needs to assess for neoplastic cells that would indicate a different neoplastic process. The cytological features need to be integrated with cyst fluid carcinoembryonic antigen and amylase measurements. Currently, molecular pathology is being integrated into the analysis of pancreatic cyst fluids. Here we will cover the cytological features and ancillary findings in cystic masses of the pancreas.

The study of biochemical profile of cyst fluid and diffusion-weighted magnetic resonance imaging in differentiating hepatic hydatid cysts from liver simple cysts.

PURPOSE: The aim of this study was to investigate the value of biochemical profile of cyst fluid and diffusion-weighted imaging (DWI) in differentiating hepatic hydatid cysts (HCs) from liver simple cysts. MATERIALS AND METHODS: Forty-six patients underwent MR imaging. Twenty-nine patients had 29 hydatid cysts and 17 patients had liver simple cysts. Thirteen patients with hydatid cysts and seven patients with liver simple cysts were evaluated with cyst fluid biochemical analysis. The concentration of glucose, protein, calcium ion (Ca2+ ) electrolyte, macroscopic appearance, and parasitological sediment were evaluated in this study. RESULTS: In the respect of biochemical analysis cyst fluid, the concentration of glucose and calcium ion of HCs was significantly higher than that of the liver simple cysts. In the respect of DWI, in the b 1000 s/mm2 value in respect of mean application data center (ADC) values, there was a statistically significant difference between HCs group (the mean value was (2.50±0.79)×10-3  mm/s2 ) and liver simple cysts group (the mean value was (2.92±0.66)×10-3  mm/s2 ). However, no statistically significant results were obtained in the ADC measurements of b 500 s/mm2 between two groups. CONCLUSION: The analysis of cyst fluid combined with the measurement of ADC values in the b 1000 s/mm2 value could be considered a promising parameter as an alternative to the differential diagnosis of hepatic hydatid cysts from liver simple cysts.

Diagnostic accuracy of haptoglobin within ovarian cyst fluid as a potential point-of-care test for epithelial ovarian cancer: an observational study.

OBJECTIVE: To investigate haptoglobin within ovarian cyst fluid (OCF) as a diagnostic biomarker for epithelial ovarian cancer (EOC) and develop an in vitro diagnostic point-of-care device test (IVDPCT) for use in the operating theatre. DESIGN: Retrospective and prospective cohort study. SETTING: South-East Asia. POPULATION: Women with suspicious ovarian cysts. METHODS: Proteomic, immunohistochemical and ELISA methods measured haptoglobin in OCF to differentiate benign and EOCs. Diagnostic performance of haptoglobin was compared with CA125, risk malignancy indices (RMI) and frozen section. Blinded validation of the IVDPCT was performed. MAIN OUTCOME MEASURES: Prediction of malignancy. RESULTS: Haptoglobin concentration measured by ELISA was 0.70 ± 0.09 mg/ml in patients with benign cysts (n = 87), 6.22 ± 0.53 mg/ml in early stage-EOC (n = 17), and 6.57 ± 0.65 mg/ml in late stage-EOC (n = 20). Haptoglobin in EOCs was significantly higher than in benign cysts (P < 0.0001). Haptoglobin using rapid colorimetric assay (RCA) on a training set had a sensitivity of 97.3% and a specificity 92.0%, comparable to ELISA and frozen sections. The haptoglobin AUROC curve was 0.999 (95% CI 0.997-1.000) compared with 0.895 (95% CI 0.814-0.977, P < 0.05) for CA125. Haptoglobin performed significantly better than all the RMIs (P < 0.01). Blinded validation studies showed a minor drop in average diagnostic performance (sensitivity 85.2% and specificity 90.5%) compared with the training set. However, when compared with frozen section, haptoglobin was no worse in diagnostic accuracy for malignancy. CONCLUSION: Haptoglobin was identified as a biomarker for the detection of EOC with potential as a point-of-care diagnostic tool. TWEETABLE ABSTRACT: Haptoglobin within ovarian cyst fluid: a biomarker for epithelial ovarian cancer and point-of-care diagnostics.

Risk factors for infection after endoscopic ultrasonography-guided drainage of specific types of pancreatic and peripancreatic fluid collections (with video).

BACKGROUND: Endoscopic ultrasonography (EUS)-guided drainage is widely used for the treatment of specific types of peripancreatic fluid collections (PFCs). Infectious complications have been reported. It is recommended that the infection rate should be assessed by measuring risk factors. The objectives of this study were to measure whether the risk of infection after EUS-guided drainage was associated with patient- and procedure-related factors. METHODS: Eighty-three patients were eligible for inclusion from September 2008 to November 2012. EUS-guided drainage was performed in all patients. Infectious complications were observed, and data on patient- and procedure-related factors were collected. Patient-related factors mainly included age, sex, etiology of PFC, and cyst location and diameter. Procedure-related factors mainly included approach of EUS-guided drainage and stent diameter. Separate multivariate logistic regression models for all EUS-guided drainage were carried out. RESULTS: Complete EUS-guided drainage was achieved in all patients. A definitive diagnosis of infection after EUS-guided drainage was made in seven patients. All seven patients had a history of acute pancreatitis, and the cyst diameters were all >15 cm. Three patients had diabetes mellitus. CONCLUSIONS: The cyst diameter was an independent risk factor for infection. Larger cysts with a diameter >15 cm should perhaps be drained initially with multiple pigtail or a larger diameter self-expandable metal stents to try to avoid infection.

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) contributes to a triple-negative test in preoperative screening of pancreatic cysts.

BACKGROUND: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) of pancreatic cysts obtains cyst fluid for cytologic and biochemical analysis, which may determine whether the cyst is mucinous and malignant, contributing to patient management. Despite this added value, EUS-FNA remains controversial in the preoperative assessment of pancreatic cysts. The objective of this study was to assess the utility of EUS-FNA in a cohort of small pancreatic cysts that were benign on imaging studies. METHODS: All pancreatic cysts that underwent initial EUS-FNA in 2006 and 2007 were retrospectively analyzed. Ninety-two patients with pancreatic cysts met the inclusion criteria. Patients who had high-risk or worrisome features on imaging studies were excluded. Cytology, histology, and cyst fluid analysis data were collected. The main outcome measurements were radiologic and clinical follow-up as well as cytopathologic and histologic results. RESULTS: EUS-FNA supported a diagnosis of a mucinous cyst in 38 of 92 patients (41%) by carcinoembryonic antigen (CEA) measurement and/or cytology. Cytology demonstrated an absence of high-grade atypia (HGA) in 89 of 92 patients (97%). The mean follow-up was 4.4 years (range, 0-7.7 years), during which 6 cysts were surgically resected and 16 cysts were resampled by at least 1 subsequent EUS-FNA. The overall negative predictive value of cytologic examination for HGA was 99%. CONCLUSIONS: EUS-FNA is a screening test that contributes to a triple-negative test for pancreatic cysts--no high-risk stigmata, no worrisome features, and no HGA on cytology--providing a negative predictive value of 99% for conservative management.

Measurement of breast-tissue x-ray attenuation by spectral mammography: first results on cyst fluid.

Knowledge of x-ray attenuation is essential for developing and evaluating x-ray imaging technologies. For instance, techniques to better characterize cysts at mammography screening would be highly desirable to reduce recalls, but the development is hampered by the lack of attenuation data for cysts. We have developed a method to measure x-ray attenuation of tissue samples using a prototype photon-counting spectral mammography unit. The method was applied to measure the attenuation of 50 samples of breast cyst fluid and 50 samples of water. Spectral (energy-resolved) images of the samples were acquired and the image signal was mapped to equivalent thicknesses of two known reference materials, which can be used to derive the x-ray attenuation as a function of energy. The attenuation of cyst fluid was found to be significantly different from water. There was a relatively large natural spread between different samples of cyst fluid, whereas the homogeneity of each individual sample was found to be good; the variation within samples did not reach above the quantum noise floor. The spectral method proved stable between several measurements on the same sample. Further, chemical analysis and elemental attenuation calculation were used to validate the spectral measurement on a subset of the samples. The two methods agreed within the precision of the elemental attenuation calculation over the mammographic energy range.

Optimizing the multimodal approach to pancreatic cyst fluid diagnosis: developing a volume-based triage protocol.

BACKGROUND: The objective of this study was to develop a triage algorithm to optimize diagnostic yield from cytology, carcinoembryonic antigen (CEA), and v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) testing on different components of a single pancreatic cyst fluid specimen. The authors also sought to determine whether cell block supernatant was suitable for CEA and KRAS testing. METHODS: Fifty-four pancreatic cysts were triaged according to a volume-dependent protocol to generate fluid (neat and supernatant) and cell block specimens for cytology, comparative CEA, and KRAS testing. Follow-up histology, diagnostic cytology, or a combined clinicopathologic interpretation was recorded as the final diagnosis. RESULTS: There were 26 mucinous cystic lesions and 28 nonmucinous cystic lesions with volumes ranging from 0.3 mL to 55 mL. Testing different components of the specimens (cell block, neat, and/or supernatant) enabled all laboratory investigations to be performed on 50 of 54 cyst fluids (92.6%). Interpretive concordance was observed in 17 of 17 cases (100%) and in 35 of 40 cases (87.5%) that had multiple components tested for CEA and KRAS mutations, respectively. An elevated CEA level (>192 ng/mL) was the most sensitive test for the detection of a mucinous cystic lesion (62.5%) versus KRAS mutation (56%) and "positive" cytology (61.5%). KRAS mutations were identified in 2 of 25 mucinous cystic lesions (8%) in which cytology and CEA levels were not contributory. CONCLUSIONS: A volume-based protocol using different components of the specimen was able to optimize diagnostic yield in pancreatic cyst fluids. KRAS mutation testing increased diagnostic yield when combined with cytology and CEA analysis. The current results demonstrated that supernatant is comparable to neat fluid and cell block material for CEA and KRAS testing.

Ablation of pancreatic cystic lesions: the use of multiple endoscopic ultrasound-guided ethanol lavage sessions.

OBJECTIVES: Determine the effectiveness of multiple endoscopic ultrasound-guided ethanol lavage (EUS-EL) sessions for attempted ablation of pancreatic cystic lesion (PCL). METHODS: Retrospective review of patients who have undergone 2 or more EUS-EL treatments of a PCL. Eligible patients had asymptomatic, benign-appearing PCL, no previous pancreatitis, and were considered poor surgical candidates. RESULTS: Final analysis was performed on 13 patients with suspected branch duct intraductal papillary mucinous neoplasms. The mean maximum cyst diameter at baseline and after 1 and 2 EUS-EL treatments was 20.1 ± 7.1, 17.0 ± 9.8 (P = 0.06), and 12.8 ± 9.6 mm (P = 0.0002), respectively. The mean surface area after 2 EUS-EL sessions: baseline, 5734 ± 6846 mm(2); 1 EUS-EL session, 4906 ± 9240 mm(2) (P = 0.52); and 2 EUS-EL sessions, 2311 ± 4093 mm(2) (P = 0.008). Complete resolution of the cystic lesion was not seen by computed tomography or magnetic resonance imaging in any patient after 1 EUS-EL but occurred in 5 (38%; P = 0.02) of 13 patients after 2 EUS-EL treatments. One patient had minor abdominal pain 1 day after the first EUS-EL session and 2 days after the second session. CONCLUSIONS: Compared with only 1 EUS-EL, 2 EUS-EL treatment results in a significantly greater decrease in the size and surface area of PCL and is associated with a significantly higher rate of image-defined cyst resolution.

Pancreatic cystic neoplasm: the role of cyst morphology, cyst fluid analysis, and expectant management.

BACKGROUND: Among pancreatic cysts, mucinous cystadenoma, and intraductal papillary mucinous neoplasms have the potential for malignant transformation. Differentiation between benign and potentially malignant/malignant (PMM) cysts remains difficult. The purpose of this study was to: (1) identify the diagnostic value of endoscopic ultrasound findings, serum, and cyst fluid tumor markers (CA19-9 and CEA), (2) determine the rate of subsequent surgical resection in patients initially managed conservatively, and (3) determine the role of cyst fluid viscosity "string sign" in differentiating pancreatic cysts. METHODS: Patients with cytologic or pathologic diagnosis for pancreatic cystic neoplasms were analyzed. RESULTS: The study included 79 patients. Cyst fluid CEA had a median of 1.0 ng/mL in benign cysts and 471.1 ng/mL in PMM cysts (P < .0001). Cyst fluid CA 19-9 was not statistically significant (P = .22). Neither serum CA 19-9 nor CEA was useful (P = .68 and P = .31). Increased cyst fluid viscosity was associated with PMM cysts (P < .0001). Median string sign was 0 mm in benign cysts and 3.5 mm in PMM cysts. The presence of thick walls (5 of 5, 100%) or intracystic growth (6 of 6, 100%) were associated with PMM cysts. Of the 50 patients with PMM cysts, 19 were treated conservatively. In those patients followed for more than 6 months, 2 of 12 (16.7%) had surgical resection after a median of 29.5 months for worrisome changes on imaging. CONCLUSIONS: The presence of a thick cyst wall or intracystic growth, elevated cyst fluid CEA, and a long "string sign" were associated with PMM cysts. 16.7% of patients with a PMM cyst managed conservatively ultimately required surgical resection.

Fluid-fluid level formation: a rare finding of extracranial head and neck schwannomas.

SUMMARY: We present 3 cases of extracranial head and neck schwannomas exhibiting fluid-fluid levels. In the described cases, CT and MR imaging showed predominantly cystic components, intermixed with cellular components. Histopathologic examinations of excised specimens revealed hemosiderin deposition, reflecting intratumoral hemorrhages, which was presumably a cause of fluid-fluid levels. Although fluid-fluid levels are nonspecific findings, schwannoma should be considered when radiologic images demonstrate marked cystic formation with fluid-fluid levels in extracranial head and neck tumors.

Massive retroperitoneal cyst during pregnancy: case report managed conservatively by percutaneous aspiration and review of literature.

Retroperitoneal cyst is an extremely rare complication of pregnancy. The management of this rare clinical entity is not well understood. An 18-year-old primigravid woman at 11 weeks of gestation with twins presented with complaints of severe nausea and vomiting. Abdominal magnetic resonance imaging showed a 25 x 18 x 10-cm retroperitoneal cyst reaching up to the level of xiphoid processes. No solid component or ascites was seen. She underwent ultrasound-guided percutaneous aspiration of the cyst and 2 L of fluid was removed. The cytology was negative for malignant cells. There was no recurrence of retroperitoneal cyst during the subsequent pregnancy. At 37 (0)/ (7) weeks' gestation, the patient spontaneously delivered the female fetuses in cephalic and breech presentation. There were only seven cases reported in the literature of retroperitoneal cysts during pregnancy between 1955 and 2008. Retroperitoneal cyst during pregnancy is characterized by its extremely rare incidence and its massive cyst size. Because of the difficulty in surgery due to the gravid uterus and close proximity to major organs and blood vessels, percutaneous aspiration of cyst could be an option during pregnancy.