Performance of endosonography-guided fine needle aspiration and biopsy in the diagnosis of pancreatic cystic lesions

OBJECTIVE: Preoperative diagnosis of cystic lesions of the pancreas remains difficult despite improvement in imaging modalities and cystic fluid analysis. The aim of our study was to assess the performance of endoscopic ultrasonography (EUS) and EUS-guided fine needle aspiration (FNA) in the diagnosis of pancreatic cystic lesions. METHODS: Data from a series of 127 consecutive patients with pancreatic cystic lesions were prospectively studied. EUS and EUS-guided FNA were performed in all patients, and cystic material was used for cytological and histological analysis as well as for biochemical and tumor markers analysis. Performance of EUS diagnosis, biochemical and tumor markers, and FNA diagnosis were compared with the final histological diagnosis obtained at surgery or postmortem examination. Sixty-seven patients underwent surgery and therefore constituted our study group. RESULTS: EUS provided a tentative diagnosis in 113 cases (89%). Cytohistological FNA provided a diagnosis in 98 cases (77%). When the results of EUS and EUS-guided FNA were compared with the final diagnosis (67 cases), EUS correctly identified 49 cases (73%), whereas FNA correctly identified 65 cases (97%). Sensitivity, specificity, positive predictive value, and negative predictive value of EUS and EUS-guided FNA to indicate whether a lesion needed further surgery were 71% and 97%, 30% and 100%, 49% and 100%, and 40% and 95%, respectively. Carbohydrate antigen 19-9 > 50,000 U/ml had a 15% sensitivity and a 81% specificity to distinguish mucinous cysts from other cystic lesions, whereas it had a 86% sensitivity and a 85% specificity to distinguish cystadenocarcinoma from other cystic lesions. CONCLUSIONS: EUS-guided FNA is a valuable tool in the preoperative diagnostic assessment of pancreatic cystic lesions.     

Solid and cystic tumor of the pancreas: clinicopathologic and genetic studies of four cases.

BACKGROUND: Solid and cystic tumor (SCT) of the pancreas can be distinguished from other pancreatic neoplasms by its nearly exclusive occurrence in young women, and its favorable prognosis after complete resection. METHODS: We experienced four cases with SCT of the pancreas, and analyzed these tumors by immunohistochemical and electron microscopic studies, as well as genetic analysis of ras oncogene mutation. RESULTS: The presented cases expressed the neuron-specific enolase in two cases, alpha1-antitrypsin and alpha1-antichymotrypsin in two cases, and vimentin in one case, which indicated that this tumor originates from pleuripotential embryonic stem cells. No patients had mutations of K-ras gene in codon 12, and further genetic analysis is required to predict the malignant potential. CONCLUSION: SCT of the pancreas appears to have limited malignant potential and the metastatic ratio is not high, although the tumor has local invasion. Therefore, an aggressive surgical approach seems fully justified.     

Obscure gastrointestinal bleeding due to duodenal infiltration of a non-functioning pancreatic neuroendocrine tumor diagnosed by capsule endoscopy: A case report

Non-functioning pancreatic neuroendocrine tumors (PNETs) are infrequent slowgrowing, clinically-silent tumors. They are incidentally detected and some of them may present in advanced stages with local involvement of surrounding structures. The diagnostic accuracy of endoscopio ultrasound (EUS) and fine needle aspiration (FNA) biopsy is significantly lower in neuroendocrine tumors (46.7%) compared with adenocarcinoma (81.4%) and other histologies (75%). Therefore, preoperative diagnosis is very difficult. Exceptionally, hey present with gastrointestinal bleeding. We present a case of a non-functioning PNET initially diagnosed as cystic serous tumor of pancreas with EUS and FNA biopsy. Two years later patient presented obscure gastrointestinal bleeding due to duodenal infiltration. Diagnosis was made by capsule endoscopy.     

Solid and cystic tumor of the pancreas Clinicopathologic and genetic studies of four cases

Background. Solid and cystic tumor (SCT) of the pancreas can be distinguished from other pancreatic neoplasms by its nearly exclusive occurrence in young women, and its favorable prognosis after complete resection. Methods. We experienced four cases with SCT of the pancreas, and analyzed these tumors by immuno-histochemical and electron microscopic studies, as well as genetic analysis of ras oncogene mutation.     

Diagnosis of tuberculous lymphadenitis using fine needle aspiration biopsy

Background: Tuberculous lymphadenitis is the commonest form of extrapulmonary tuberculosis. However, the optimal approach to diagnosis, employing biopsy by either fine needle aspiration (FNA) or surgical excision, remains uncertain. Aims: To evaluate the diagnostic value of biopsy using each of the component diagnostic modalities of FNA (microscopy, cytology and culture), and compare these with excision biopsy in the diagnosis of tuberculous lymphadenitis in a predominantly migrant population in Melbourne. Methods: A retrospective examination of tuberculous lymphadenitis cases presenting to Western Health over 12 years was conducted. Using a reference method of positive culture of Mycobacterium tuberculosis, the diagnostic sensitivities of each modality employed in FNA were determined. Results: Forty‐two subjects having FNA and 30 having excision biopsy as the initial investigation were compared. Among specimens obtained by FNA, sensitivity of microscopy was 18% (95% confidence interval (CI): 5–40%) and sensitivity of cytology was 38% (95% CI: 20–59%). For specimens obtained by excision biopsies, sensitivities for microscopy and histology were 17% (95% CI: 2–32%) and 96% (95% CI: 88–100%) respectively. Sensitivity of culture performed on FNA specimens was 86% (95% CI: 65–97%). Conclusions: Given the relatively high sensitivity of mycobacterial cultures from FNA, this study supports its routine use as the initial investigation in most patients with suspected tuberculous lymphadenitis. Microscopy and cytology add relatively little to the clinical utility of FNA.     

Pancreatic schwannoma,an extremely rare and challenging entity: Report of two cases and review of literature

Pancreatic schwannoma is a rare benign tumor, for which the preoperative and intraoperative definitive diagnosis is quite challenging. We present the clinical, radiological and pathologic features of two primary pancreatic schwannomas identified in our pathology database over a period of 30 years at our tertiary care hospital. To better understand the clinico-pathological and radiological features of this entity, we provide a comprehensive review of 73 cases described in the English literature, along with our two cases. This review will especially focus on preoperative and intraoperative diagnosis to assess their accuracy for pancreatic schwannoma. The three most common preoperative diagnoses based on imaging for pancreatic schwannomas were cystic neoplasm (56%), pancreatic neuroendocrine tumor (29%) and mucinous cystic neoplasm (26%). Imaging could not definitely diagnose pancreatic schwannoma in any of the reported cases. To obtain a definite diagnosis before surgery, 25 cases underwent imaging-guided fine-needle aspiration (FNA)/biopsy, of which 60% were correctly reported as benign with definite diagnosis of pancreatic schwannoma in 48%. A higher diagnostic accuracy was observed in biopsies (71%) than FNA (37%). In addition, an intraoperative frozen section was carried out in 15 cases, and 47% were correctly diagnosed. Despite relatively low accuracy, preoperative histological assessment can be helpful in surgical managment. A core tissue specimen is recommended to improve the diagnostic accuracy in this setting.     

Molecular assessment of endoscopically collected pancreatic juice and duodenal fluid from patients with pancreatic diseases

One concern associated with pancreatic diseases is the poor prognosis of pancreatic cancer. Even with advances in diagnostic modalities, risk stratification of premalignant lesions and differentiation of pancreatic cysts are challenging. Pancreatic lesions of concern include intraductal papillary mucinous neoplasms, mucinous cystic neoplasms, serous cystadenomas, pseudocysts, and retention cysts, as well as cystic degeneration of solid tumors such as solid pseudopapillary neoplasms and pancreatic neuroendocrine neoplasms. Pancreatic juice obtained during endoscopic retrograde cholangiopancreatography has previously been used for the detection of KRAS mutation. Recently, duodenal fluid, which can be obtained during the relatively minimally invasive procedures of endoscopic ultrasound (EUS) and esophagogastroduodenoscopy, and cyst fluid collected by EUS-guided fine-needle aspiration (FNA) were used for molecular biological analysis. Furthermore, advanced analytic methods with high sensitivity were used for the detection of single and multiple markers. Early detection of malignant pancreatic tumors and risk stratification of premalignant tumors can be performed using duodenal fluid samples with a single marker with high sensitivity. Technological advances in simultaneous detection of multiple markers allow for the differentiation of cystic pancreatic tumors. One thing to note is that the clinical guidelines do not recommend pancreatic cyst fluid and pancreatic juice (PJ) sampling by EUS-FNA and endoscopic retrograde cholangiopancreatography, respectively, in actual clinical practice, but state that they be performed at experienced facilities, and duodenal fluid sampling is not mentioned in the guidelines. With improved specimen handling and the combination of markers, molecular markers in PJ samples may be used in clinical practice in the near future.     

Resektion zystischer Pankreastumoren

Cystic tumors of the pancreas are diagnosed increasingly more due to increasing life expectancy and the moderate use of modern radiological diagnostics. Intraductal papillary mucinous neoplasms of the pancreas (IPMN), mucinous cystic neoplasms (MCN), solid pseudopapillary neoplasms (SPN) and serous cystic neoplasms (SCN) represent over 90?% of all cystic neoplasms of the pancreas. Although serous cystic lesions have a low or even no potential for malignant transformation, they are mostly resected when symptomatic. In contrast, mucinous lesions have an increased malignant potential and should therefore be resected in almost all cases. While this is true for all cases of MCNs and SPNs this is controversial for all IPMNs as they show a wide spectrum of morphological variants. The IPMNs may arise in the main pancreatic duct, major side branches or in both (mixed type). Although all IPMNs are considered to be precursor lesions to pancreatic adenocarcinomas it is not clear what the time course of such potential neoplastic transformation might be and whether all lesions progress to malignant tumors. As no currently used diagnostic test can reliably differentiate between benign and malignant tumors, the majority of newly diagnosed IPMNs should undergo surgical resection. According to current treatment guidelines (Sendai criteria), asymptomatic side branch IPMNs of less than 3 cm in diameter without suspicious radiological features, such as nodules, thickness of the cystic wall or size progression can be treated conservatively without the need for surgical resection. Recently, this approach has become controversial due to a relevant number of IPMNs reported as Sendai negative that showed malignant transformation on final histological examination.     

Synchronous pancreatic serous cystic tumor, intraductal papillary mucinous tumor and gastric carcinoma: report of a case

Synchronous cystic tumors of the pancreas are rarely reported in the literature. We report an unusual case of synchronous pancreatic serous cystic tumor (SCT) and intraductal pancreatic mucinous tumor (IPMT) with concomitant gastric carcinoma. This study highlights the importance of careful intra-operative and pathologic examination for concomitant pancreatic neoplasms.     

Endosonographic features predictive of benign and malignant gastrointestinal stromal cell tumours

BACKGROUND/AIM: Some endoscopic ultrasonographic (EUS) features have been reported to be suggestive of malignancy in gastrointestinal stromal cell tumours (SCTs). The aim of this study was to assess the predictive value of these features for malignancy. METHODS: A total of 56 histologically proven cases of SCT studied by EUS between 1989 and 1996 were reviewed. There were 42 gastric tumours, 12 oesophageal tumours, and two rectal tumours. The tumours were divided into two groups: (a) benign SCT, comprising benign leiomyoma (n = 34); (b) malignant or borderline SCT (n = 22), comprising leiomyosarcoma (n = 9), leiomyoblastoma (n = 9), and leiomyoma of uncertain malignant potential (n = 4). The main EUS features recorded were tumour size, ulceration, echo pattern, cystic spaces, extraluminal margins, and lymph nodes with a malignant pattern. The two groups were compared by univariate and multivariate analysis. RESULTS: Irregular extraluminal margins, cystic spaces, and lymph nodes with a malignant pattern were most predictive of malignant or borderline SCT. Pairwise combinations of the three features had a specificity and positive predictive value of 100% for malignant or borderline SCT, but a sensitivity of only 23%. The presence of at least one of these three criteria had 91% sensitivity, 88% specificity, and 83% predictive positive value. In multivariate analysis, cystic spaces and irregular margins were the only two features independently predictive of malignant potential. The features most predictive of benign SCTs were regular margins, tumour size < or = 30 mm, and a homogeneous echo pattern. When the three features were combined, histology confirmed a benign SCT in all cases. CONCLUSIONS: The combined presence of two out of three EUS features (irregular extraluminal margins, cystic spaces, and lymph nodes with a malignant pattern) had a positive predictive value of 100% for malignant or borderline gastrointestinal SCT. Tumours less than 30 mm in diameter with regular margins and a homogeneous echo pattern are usually benign.     

Endoscopic ultrasound in the evaluation of pancreatic neoplasms-solid and cystic: A review

Pancreatic neoplasms have a wide range of pathology, from pancreatic adenocarcinoma to cystic mucinous neoplasms. Endoscopic ultrasound(EUS) with or without fine needle aspiration(FNA) is a helpful diagnostic tool in the work-up of pancreatic neoplasms. Its utility in pancreatic malignancy is well known. Over the last two decades EUS-FNA has become a procedure of choice for diagnosis of pancreatic adenocarcinoma. EUS-FNA is highly sensitive and specific for solid lesions, with sensitivities as high as 80%-95% for pancreatic masses and specificity as high as 75%-100%. Multiple aspects of the procedure have been studied to optimize the rate of diagnosis with EUS-FNA including cytopathologist involvement, needle size, suctioning and experience of endoscopist. Onsite pathology is one of the most important elements in increasing diagnostic yield rate in EUS-FNA. EUS-FNA is valuable in diagnosing rare and atypical pancreatic neoplasms including neuroendocrine, lymphoma and metastatic disease. As more and more patients undergo cross sectional imaging, cystic lesions of the pancreas are becoming a more common occurrence and EUS-FNA of these lesions can be helpful for differentiation. This review covers the technical aspects of optimizing pancreatic neoplasm diagnosis rate, highlight rare pancreatic neoplasms and role of EUS-FNA, and also outline the important factors in diagnosis of cystic lesions by EUS-FNA.     

EUS-guided FNA in the diagnosis of pancreatic neuroendocrine tumors before surgery

BACKGROUND: The use of EUS for precise preoperative evaluation of pancreatic neuroendocrine tumors is well established; up to 80% of insulinomas can be localized. However, the EUS appearance of pancreatic neuroendocrine tumors can be similar to that of benign peripancreatic lymph nodes. The aim of this study was to evaluate the role of EUS-guided FNA in this setting. METHODS: Thirty patients (18 women, 12 men) with 33 pancreatic/peripancreatic lesions confirmed by surgery underwent EUS-guided FNA between February 1997 and September 2002. Transabdominal US and CT were obtained in all patients before EUS. The diagnosis of pancreatic neuroendocrine tumor was established based on morphologic appearance and immunohistochemical staining of cytologic and surgical specimens. RESULTS: EUS detected 32 of the 33 (96.9%) lesions (mean diameter 20 mm, range 5-97 mm). There was one complication (abdominal pain). For the 30 patients, the following diagnoses were made: functioning pancreatic neuroendocrine tumor (16 patients), non-functioning pancreatic neuroendocrine tumor (7), peripancreatic lymph node (5), inflammatory intrapancreatic nodule (1), and peripancreatic splenosis (1). Sensitivity, specificity, positive and negative predictive values, and accuracy of EUS-guided FNA were 82.6%, 85.7%, 95%, 60%, and 83.3%, respectively. There was one false-positive diagnosis by EUS-guided FNA and 4 false-negative diagnoses. In two of the latter cases, EUS-guided FNA was unsuccessful. CONCLUSIONS: EUS-guided FNA is accurate and safe for the diagnosis of pancreatic neuroendocrine tumor and may have a role in determining management strategy.     

Diagnostic dilemmas in patients with cystic neoplasms of the pancreas

Cystic neoplasms of the pancreas (CNP) are rare lesions that can be difficult to diagnose preoperatively. Twenty patients with cystic neoplasms of the pancreas including five microcystic adenomas, six benign mucinous cystic neoplasms, three malignant mucinous cystic neoplasms, two solid and papillary epithelial neoplasms, and four cystic neuroendocrine tumors were treated at a single institution between 1962 and 1987. The average duration of symptoms prior to diagnosis was 10 months. Five patients were asymptomatic. Forty percent of patients presented with an abdominal mass. Plain abdominal x-rays and UGI barium contrast studies were never diagnostic. Ultrasonography, computerized tomography (CT) and visceral angiography aided in the correct diagnosis in 28%, 36%, and 75% of patients studied, respectively. Overall a correct diagnosis was made preoperatively in only 35% of patients. Twelve of 13 patients were correctly diagnosed at laparotomy with intraoperative biopsy. Without biopsy the mass was misdiagnosed at laparotomy in five of six cases. CNP must be suspected in any patients who present with an upper abdominal mass with or without abdominal pain and no history of pancreatitis. CT may be diagnostic in up to one third of cases and should be obtained routinely to demonstrate the proximity of the lesion to other structures. Visceral angiography should also be obtained prior to operation. A generous incisional biopsy should be obtained of all pancreatic cysts that are not to be resected.     

Cystic tumors of the liver： A practical approach

Biliary cyst tumors （cystadenoma and cystadenocarcinoma） are an indication for liver resection. They account for only 5% of all solitary cystic lesions of the liver, but differential diagnosis with multiloculated or complicated biliary cysts, atypical hemangiomas, hamartomas and lymphangiomas may be difficult. The most frequent challenge is to differentiate biliary cyst tumors from hemorrhagic cysts. Computerized tomography （CT） and magnetic resonance imaging （MRI） are often not diagnostic and in these cases fine needle aspiration （FNA） is used to confirm the presence of atypical biliary cells. FNA, however, lacks adequate sensitivity and specificity and should always be used in conjunction with imaging. Pre-operative differentiation of cystadenoma from cystadenocarcinoma is impossible and surgery must be performed if a biliary cyst tumor is suspected. When multiple cystic lesions are observed throughout the liver parenchyma, it is important to exclude liver metastasis, of which colonic cancer is the most common primary site. Multiple biliary hamartomas （von Meyenburg complex） can appear as a mixture of solid and cystic lesions and can be confused with cystic metastasis. Strong and uniform T2 hyperintensity on MRI is usually diagnostic, but occasionally a percutaneous biopsy may be required.     

Diagnostic dilemmas in patients with cystic neoplasms of the pancreas

Summary Cystic neoplasms of the pancreas (CNP) are rare lesions that can be difficult to diagnose preoperatively. Twenty patients with cystic neoplasms of the pancreas including five microcystic adenomas, six benign mucinous cystic neoplasms, three malignant mucinous cystic neoplasms, two solid and papillary epithelial neoplasms, and four cystic neuroendocrine tumors were treated at a single institution between 1962 and 1987. The average duration of symptoms prior to diagnosis was 10 months. Five patients were asymptomatic. Forty percent of patients presented with an abdominal mass. Plain abdominal x-rays and UGI barium contrast studies were never diagnostic. Ultrasonography, computerized tomography (CT) and visceral angiography aided in the correct diagnosis in 28%, 36%, and 75% of patients studied, respectively. Overall a correct diagnosis was made preoperatively in only 35% of patients. Twelve of 13 patients were correctly diagnosed at laparotomy with intraoperative biopsy. Without biopsy the mass was misdiagnosed at laparotomy in five of six cases. CNP must be suspected inany patients who present with an upper abdominal mass with or without abdominal pain and no history of pancreatitis. CT may be diagnostic in up to one third of cases and should be obtained routinely to demonstrate the proximity of the lesion to other structures. Visceral angiography should also be obtained prior to operation. A generous incisional biopsy should be obtained of all pancreatic cysts that are not to be resected.     

Differentiation of cystic pancreatic neoplasms and pseudocysts by conventional and echo-enhanced ultrasound

BACKGROUND AND AIMS: Echo-enhanced sonography is a non-invasive and increasingly used procedure for the differentiation of pancreatic tumors. However, the diagnostic accuracy of this procedure compared to conventional ultrasound for the differential diagnosis of cystic pancreatic neoplasms from pseudocysts has never been investigated in a prospective study. METHODS: Thirty-one patients with a cystic pancreatic lesion at the conventional ultrasound (mean age 57 years, range 36-82 years) were included in the study. Sonography was performed by an experienced examiner who was unaware of the patients' clinical diagnosis. The exact diagnosis was based on histological evidence from biopsy examination (surgical or transabdominal fine needle biopsy for all cystic neoplasms and five pseudocysts), or a follow-up of at least 18 months (four pseudocysts). RESULTS: Of the 31 patients, 19 had cystadenomas, three had cystadenocarcinomas, and nine had pseudocysts. Only 27% of the cystadenomas and 67% of the pseudocysts could be correctly classified by conventional ultrasound. Conversely, 95% of the cystadenomas (P = 0.0001) and all pseudocysts were diagnosed correctly by echo-enhanced sonography. The sensitivity of echo-enhanced sonography with respect to diagnosing cystadenoma was 95% and its specificity was 92%. The corresponding values for pseudocysts were both 100%. CONCLUSION: Echo-enhanced sonography has a high sensitivity and specificity in the differential diagnosis of cystic pancreatic tumors. With this procedure the differentiation of cystadenomas and pseudocysts can be improved. However, histology is the standard of reference.     

Intraductal papillary mucinous tumors of the pancreas

Cystic neoplasms of the exocrine pancreas are a small fraction of pancreatic tumors. Within that group of cystic neoplasms, intraductal papillary mucinous tumors (IPMTs) can be distinguished from mucinous cystic neoplasms, serous cystic neoplasms, and pseudopapillary cystic tumors. Awareness of IPMTs has increased since the World Health Organization classified these tumors as its own group in 1996. Because of their favorable prognosis, an extensive diagnostic workup for IPMTs should be performed in patients presenting with cystic lesions of the pancreas. This workup often leads to the diagnosis and the predominant tumor location and size, although the extent of the ductal changes can only be established by histopathology. Surgical resection is the therapy of choice for IPMTs. The type of resection depends upon the extent of the quantitative and qualitative ductal involvement. Total pancreatectomy is currently the treatment for an IPMT that comprises the entire main duct.     

内镜超声检查术对胰腺肿瘤早期诊断的价值

目的探讨内镜超声检查术（EUS）、管内超声检查术（IDUS）及超声内镜引导下细针穿刺术（EUS-FNA）对胰腺肿瘤早期诊断的价值。方法回顾性分析和比较188例胰腺小占位病灶的EUS、IDUS、EUS—FNA及其他影像学检查结果。结果（1）EUS诊断小胰腺癌的准确率是95．6％（44／46）,优于B超58．6％（27／46）、CT77．4％（24／31）、MRI76．2％（16／21）及内镜逆行胰胆管造影术（ERCP）85．3％（29／34）。小胰腺癌EUS声像图主要表现为类圆形、边界清楚、边缘不规则的低回声肿块,内部回声多均匀。（2）25例胰腺小占位病灶行IDUS检查,其准确率是100．0％（25／25）,明显优于B超32．0％（8／25）、CT52．9％（9／17）及MRI57．9％（11／19）等检查。（3）18例胰腺小占位病灶行EUS—FNA,其准确率是66．7％（12／18）。（4）EUS诊断胰腺假性囊肿的准确率是100．0％（27／27）,明显优于13超52．0％（13／25）、CT66、7％（12／18）、MRI82．4％（14／17）及ERCP78．9％（15／19）;对胰腺囊性肿瘤分类鉴别诊断总的准确率是57．7％（15／26）,优于B超19．2％（5／26）、CT36．4％（8／22）、MRI37．5％（6／16）及ERCP50．0％（7／14）等检查。结论EUS、IDUS及EUS-FNA对胰腺肿瘤的早期诊断具有重要价值。     

Assessment of nondiagnostic ultrasound-guided fine needle aspirations of thyroid nodules

Thyroid nodules are common. Evaluation of patients with thyroid nodules typically includes fine needle aspiration biopsy (FNA), an approach that has proven to be accurate for the detection of thyroid cancer. Although the majority of biopsies are adequate for a cytological diagnosis, up to 20% will be insufficient or nondiagnostic. Current opinion suggests that such aspirates should be repeated, although no systematic study has investigated the usefulness of this approach, especially when ultrasound guidance is used to direct the initial FNA. We sought to define the predictors and optimal follow-up strategy for initial nondiagnostic ultrasound-guided FNAs of thyroid nodules. Data were collected for all patients at the Brigham and Women's Hospital Thyroid Nodule Clinic between 1995-2000 who underwent ultrasound-guided FNA of a thyroid nodule. All patients with nondiagnostic cytology were advised to return for a repeat ultrasound-guided FNA. Patient age, gender, nodule size, cystic content, solitary vs. multinodular thyroid, and nodule location were documented and evaluated as possible predictors of a nondiagnostic biopsy in a multivariable model. The rate of diagnostic cytology obtained on repeat ultrasound-guided FNA was calculated. A total of 1128 patients with 1458 nodules were biopsied over a 6-yr period. A total of 1269 aspirations (950 patients) were diagnostic, and 189 (178 patients) were nondiagnostic. The cystic content of each nodule was the only significant independent predictor of nondiagnostic cytology (P < 0.001). The fraction of specimens with initial nondiagnostic cytology increased with greater cystic content (P < 0.001 for trend). A diagnostic ultrasound-guided FNA was obtained on the first repeat biopsy in 63% of nodules and was inversely related to increasing cystic content of each nodule (P = 0.03). One hundred and nineteen patients with 127 nodules returned for follow-up as advised, and malignancy was documented in 5%. Despite ultrasound-guided FNA, there remains a significant risk of initial nondiagnostic cytology, largely predicted by the cystic content of each nodule. Repeat aspiration is often successful and should be the standard approach to such nodules, given their risk of malignancy.     

Endosonographic and cyst fluid characteristics of cystic pancreatic neuroendocrine tumours: A multicentre case series

BackgroundPancreatic neuroendocrine tumours are uncommon neoplasms which may rarely be cystic. Differentiation from other more common cystic neoplasms may be difficult.AimsTo describe the morphologic, cytologic, and cyst fluid characteristics of cystic pancreatic neuroendocrine tumours.MethodsRetrospective analysis of consecutive patients referred for endosonographic evaluation of pancreatic cysts at four centres.Results27 patients (12 males) with cystic pancreatic neuroendocrine tumours were identified. Prior to endosonography, this tumour was suspected in only 2 patients based on presenting symptoms (7.4%). The median cyst size was 35 mm (range 8–80 mm). Wall thickening was identified in 13 cases. The median carcinoembryonic antigen level was 1.25 (range 0.6–500). Fine needle aspiration cytology in 17 of 24 patients confirmed neuroendocrine tumour (71%). In 8 of 9 patients who had needle targeting of the cyst wall, cytology was consistent with neuroendocrine tumour (88.9%). 18 patients underwent surgical resection.ConclusionsCystic pancreatic neuroendocrine tumour was rarely suspected, including by cross-sectional imaging. Wall thickening was identified in approximately half of cases on endosonography. Cyst fluid was typically non-viscous with very low carcinoembryonic antigen levels. Targeting the wall during fine needle aspiration had a high diagnostic yield and should be performed.