Lymphoepithelial cyst of the pancreas. No evidence for Epstein-Barr virus-related pathogenesis.

Compared to pseudocyst formation after prior pancreatitis, true cysts of the pancreas are rare. Pancreatic cysts with irregular wall components or a mucinous content raise the suspicion for the presence of a cystic neoplasm, and surgical resection is recommended. A case of a patient with a history of prostate cancer is described in whom a cyst of the pancreatic tail was discovered incidentally. Based on the radiographic features, which did not support the presence of a serous cystadenoma, a spleen-preserving distal pancreatectomy was performed. Histologic features were characteristic for a lymphoepithelial cyst (LEC) of the pancreas, lined with thinned squamous epithelium surrounded by benign lymphoid tissue. Since LECs of the parotid gland, which are associated with acquired human immunodeficiency, are frequently related to Epstein-Barr virus (EBV) infection, EBV in situ hybridization was performed and did not reveal evidence for EBV. Twenty-eight instances of pancreatic LECs have been reported, primarily affecting adult males, without evidence of increased numbers of EBV-positive cells. The pathogenesis, differential diagnosis, and clinical implications of lymphoepithelial pancreatic cysts are discussed.     

Lymphoepithelial cysts of the pancreas a management dilemma

Pancreatic lymphoepithelial cysts (LECs) are rare, benign lesions that are typically unexpected post-operative pathological findings. We aimed to review clinical, radiological and pathological features of LECs that may allow their pre-operative diagnosis. Histopathology databases of two large pancreatic units were searched to identify LECs and notes reviewed to determine patient demographic details, mode of presentation, investigations, treatment and outcome. Five male and one female patients were identified. Their median age was 60 years. Lesions were identified on computed tomography performed for abdominal pain in two patients, and were incidentally observed in four patients. Five LECs were located in the tail and one in the body of the pancreas, with a median cyst size of 5 cm. Obtaining cyst fluid was difficult and a largely acellular aspirate was yielded. The pre-operative diagnosis was mucinous cystic neoplasm in all patients. This series of patients were treated distal pancreatectomy and splenectomy. A retrospective review of radiological examinations suggested that LECs have a relatively low signal on T2 imaging and a high signal intensity on T1 weighted images. LECs appear more common in elderly males, and are typically incidental, large, unilocular cysts. Close attention to signal intensity on MRI may allow pre-operative diagnosis of these lesions.     

Lymphoepithelial cyst of pancreas. Role of endoscopic ultrasound guided fine needle aspiration

Lymphoepithelial cysts of the pancreas are extremely rare, benign, nonneoplastic cysts that may simulate pseudocysts or cystic neoplasm of the pancreas. Endosonographic and cytologic features of pancreatic lymphoepithelial cysts are poorly characterized because of their rarity. However, appropriate prospective diagnosis of pancreatic lymphoepithelial cysts using endoscopic ultrasound-guided fined needle aspiration (EUS-FNA) cytology may permit conservative management because of their benign nature. We conducted a MEDLINE search using the MeSH terms "pancreas", "cyst" and identified 16 patients who were diagnosed with endosonography or computerized tomography (CT) guided fine needle aspiration. Usefulness and pitfalls of EUS- or CT-guided cyst fluid analysis in the pre-operative diagnosis of pancreatic lymphoepithelial cysts are discussed.     

Lymphoepithelial cysts of the pancreas: The use of endoscopic ultrasound-guided fine-needle aspiration in diagnosis

Lymphoepithelial cysts (LECs) are rare non-neoplastic lesions that can appear as a complex cyst or a mass in the pancreas. Cytology from endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) can be helpful in making a diagnosis with the aim of avoiding unnecessary surgical resection. A case involving a 51-year-old woman with lower abdominal pain who was found to have a multiloculated cystic lesion at the junction of the pancreatic body and tail is described. Cytology from EUS-FNA was consistent with a pancreatic LEC. The lesion was managed conservatively and follow-up imaging of the cyst over the following two years was unchanged. The patient remains clinically well. Cytology from EUS-FNA can help distinguish LECs from cystic neoplasms, thus preventing radical surgical resection of this benign pancreatic cyst.     

Case of lymphoepithelial cyst of the pancreas]

We recently experienced a case of lymphoepithelial cyst of the pancreas, which is a rare benign pancreatic cystic tumor. A 59-year-old-man was pointed out as having a pancreatic tumor based on abdominal ultrasonography findings obtained during a medical check-up. Thereafter, abdominal ultrasonography, CT, and MRI studies revealed the presence of a multi-cystic tumor in the pancreas body to tail measuring 45 mm in size which had no infiltrating tendency. The operative findings showed a yellowish-white colored cystic tumor covered with a thin capsule, which could be easily extirpated from the pancreas. The dissected tumor, which contained a curd-like material and a condensed milky liquid, was diagnosed to be a lymphoepithelial cyst of the pancreas based on the pathological findings. Similar reports of lymphoepithelial cysts arising in the pancreas have recently been increasing.     

Lymphoepithelial cyst of the pancreas

We experienced a rare case of lymphoepithelial cyst of pancreas. The patient was a 68-year-old man in whom a cystic lesion in the pancreas was detected when he was admitted for chronic renal failure. On ultrasonography, we detected a cystic lesion, 3 cm in diameter, with a septum, in head and body of the pancreas. On both computed tomography and magnetic resonance imaging, the cystic lesion did not show solid components. Endoscopic retrograde cholangiopancreatography showed no abnormality in the pancreatic duct and did not detect the cystic lesion. Although the lesion showed no evidence of malignancy on the images, we could not rule out malignancy, since high levels of carcinoembryonic antigen and carbohydrate antigen 19-9 were detected. We therefore performed a pancreatoduodenectomy. In the resected specimen, the lesion was a well-circumscribed and multilocular cyst that contained yellowish-white keratinous material and had no solid components. Histologically, the cyst wall was composed of mature keratinizing squamous epithelium and lymphoid tissue; it was diagnosed as a benign lymphoepithelial cyst of the pancreas.     

Lymphoepithelial cyst of the pancreas associated with elevated CA 19-9 levels

An extremely rare case of a lymphoepithelial cyst associated with persistent elevation of serum carbohydrate antigen (CA) 19-9 levels is described. A 72-year-old man was incidentally found to have a cystic tumor in the uncus of the pancreas and to have a high serum CA 19-9 level. At 2-year follow up, the tumor size had gradually increased and the high CA 19-9 level persisted. Because the malignant potential of the tumor could not be ruled out, a laparotomy was performed. The tumor was excised from the pancreas. On pathological examination, the tumor was proven to be a lymphoepithelial cyst. After the operation, the patient’s serum CA 19-9 level decreased to the normal range. Lymphoepithelial cysts of the pancreas are a rare, benign entity. They are true pancreatic cysts, characterized by a mature, keratinizing, squamous lining surrounded by lymphoid tissue. Because the treatment options and the prognosis of these entities are quite different from those of other cystic neoplasms of the pancreas, preoperative differential diagnosis is the main issue. Thus, although they are rare, lymphoepithelial cysts should be considered in the differential diagnosis of cystic tumors of the pancreas.     

Clinical and radiological feature of lymphoepithelial cyst of the pancreas

A lymphoepithelial cyst(LEC)of the pancreas is a rare benign lesion.Because patients with LEC of the pancreas have a good prognosis,it is important that these lesions are accurately differentiated from other more aggressive pancreatic neoplasms for an appropriate treatment strategy.Previous studies have reported that a definitive diagnosis of LEC often cannot be obtained based solely on the findings of preoperative imaging(e.g.,Computed tomography or Magnetic resonance imaging).In this study,we reviewed four cases of pancreatic LECs to investigate the feature of LECs.We reviewed these cases with regard to symptoms,imaging findings,surgical procedures,and other clinical factors.We found that LEC was associated with unique characteristics on imaging findings.A preoperative diagnosisof LEC may be possible by comprehensively evaluating its clinical and imaging findings.     

Lymphoepithelial cyst of the pancreas: a new case report

We report the case of a lymphoepithelial cyst of the pancreas discovered by chance on imaging in a 54-year old man. CT-scan showed a 10 cm hypodense multilocular cystic tumor of the pancreatic isthmus. Fine-needle aspiration did not provide further information. Due to the lack of preoperative diagnosis and mostly because it was not known if the cyst was malignant or benign, the patient underwent a cephalic duodenopancreatectomy. Lymphoepithelial cyst of the pancreas is a rare benign lesion which is difficult to diagnose before surgery. Histologically, the cyst wall is lined by mature keratinizing squamous epithelium and a distinct surrounding lymphoid tissue layer. The cysts are filled with keratin plugs that are not always visualized on imaging. Cytological and histological analysis of fine-needle aspiration material if the sample material is sufficient may help avoid extensive surgery.     

Contribution of endosonography in an uncommon case of pancreatic cysts

Here we present the case of a 35-year-old female patient with long standing dyspepsia and imaging studies showing the presence of multiple cysts in the head and tail of the pancreas. The patient underwent endosonography that confirmed the presence of multiple simple cysts throughout the entirety of the pancreas without dilation of the pancreatic duct. The majority of the cysts were less than one centimeter in size, and the largest cyst showed a honeycomb appearance. Cytology of aspirates from the two largest cysts was compatible with benign pancreatic cysts. Endosonography also revealed cysts within the left kidney and spleen. Genetic testing confirmed Von Hippel-Lindau disease. We highlight this case because it is unusual for Von Hippel-Lindau disease, a rare clinical entity, to present solely with cysts in the absence of more common manifestations, such as hemangioblastomas in the central nervous system and malignancy.     

Accuracy of preoperative workup in a prospective series of surgically resected cystic pancreatic lesions

Abstract

Background. Magnetic resonance imaging (MRI) and endoscopic ultrasound (EUS) are considered useful techniques in the evaluation of pancreatic cysts. Aim of this study was to prospectively compare the diagnostic value of these techniques. Methods. This study included consecutive patients who underwent MRI, EUS, and EUS-FNA for a pancreatic cyst that was eventually resected surgically. Observers scored for cyst characteristics, a distinction between mucinous and non-mucinous cysts and a suspicion of malignancy. The interobserver agreement between MRI and EUS was calculated. Results. A total of 32 patients were included. Sensitivity for diagnosing a mucinous cyst was 78% for EUS versus 91% for MRI. Sensitivity for detecting malignancy was 25% (1/4) and 50% (2/4) for EUS and MRI respectively. Sensitivity of EUS-FNA for diagnosing a mucinous cyst (positive cytology and/or CEA >192 ng/ml) was 61%. Sensitivity for detecting malignancy (positive cytology) was 1/4 (25%). Interobserver agreement between MRI and EUS for the features was poor to fair. Conclusion. MRI and EUS are comparable techniques for the morphological characterization of pancreatic cysts. Combined sensitivity of EUS and MRI was higher than the sensitivity of one of the techniques alone. For diagnosing a mucinous cyst, FNA findings showed a low sensitivity, but a high specificity.     

Current status on the diagnosis and management of pancreatic cysts in the Asia-Pacific region: role of endoscopic ultrasound

Endoscopic ultrasound (EUS) and EUS-guided fine-needle aspiration (EUS-FNA) play increasingly prominent roles in the diagnosis and management of pancreatic cysts. The Asian Consortium of Endoscopic Ultrasound was recently formed to conduct collaborative research in this area. This is a review of literature on true pancreatic cysts. Due to the lack of systematic studies, there are no robust data on the true incidence of pancreatic cystic lesions in Asia and any change in over the recent decades. Certain EUS morphological features have been used to predict particular types of pancreatic cysts. Pancreatic cyst fluid viscosity, cytology, pancreatic enzymes, and tumor markers, in particular carcinoembryonic antigen, can aid in the diagnosis of pancreatic cysts. Hemorrhage and infection are the most common complications of EUS-FNA of pancreatic cysts. Pancreatic cysts can either be observed or resected depending on the benign or malignant nature, or malignant potential of the lesions. Guidelines from an international consensus did not require positive cytological findings to be present in their recommendation for resection, which included all mucinous cystic neoplasms, all main-duct intraductal papillary mucinous neoplasms (IPMN), all mixed IPMN, symptomatic side-branch IPMN, and side-branch IPMN larger than 3 cm. In patients with poor surgical risks, EUS-guided cyst ablation of mucinous pancreatic cysts is an alternative. As long-term prospective data on pancreatic cysts are still not available in Asia, management strategies are largely based on risk stratification by surgical risk and malignant potential. Gene expression profiling of pancreatic cyst fluid and confocal laser endomicroscopic examination of pancreatic cysts are novel techniques currently being studied.     

Management of mucinous cystic neoplasms of the pancreas

The purpose of this study was to investigate the actual management of mucinous cystic neoplasm (MCN) of the pancreas. A systematic review was performed in December 2009 by consulting PubMed MEDLINE for publications and matching the "pancreatic mucinous cystic neoplasm", "pancreatic mucinous cystic tumour", "pancreatic mucinous cystic mass", "pancreatic cyst", and "pancreatic cystic neoplasm" to identify English language articles describing the diagnosis and treatment of the mucinous cystic neoplasm of the pancreas. In total, 16 322 references ranging from January 1969 to December 2009 were analysed and 77 articles were identified. No articles published before 1996 were selected because MCNs were not previously considered to be a completely autonomous disease. Definition, epidemiology, anatomopathological findings, clinical presentation, preoperative evaluation, treatment and prognosis were reviewed. MCNs are pancreatic mucinproducing cysts with a distinctive ovarian-type stroma localized in the body-tail of the gland and occurring in middle-aged females. The majority of MCNs are slow growing and asymptomatic. The prevalence of invasive carcinoma varies between 6% and 55%. Preoperative diagnosis depends on a combination of clinical features, tumor markers, computed tomography (CT), magnetic resonance imaging, endoscopic ultrasound with cyst fluid analysis, and positron emission tomography-CT. Surgery is indicated for all MCNs.     

Lymphoepithelial cyst of the pancreas]

A 66-year-old woman presented with abdominal pain and weight loss. Ultrasonography and computed tomography demonstrated a cystic lesion of the pancreas. After surgical resection, the patient's symptoms disappeared. Microscopic examination of the cyst lining showed mature, keratinizing squamous epithelium, surrounded by lymphoid tissue. Only three cases of this type of lesion, called "lymphoepithelial cyst", have been described previously. Histogenesis of this particular type of cyst is not well know, but can be histologically differentiated from other pancreatic cysts.     

Frequent multiple c‐ki‐ras oncogene activation in pancreatic juice from patients with benign pancreatic cysts

Background: We detected benign pancreatic cysts in more than half of 12 cases of in situ pancreatic cancer. A few investigators, having detected K‐ras mutation in pancreatic juice before the clinical diagnosis of pancreatic cancer, have suggested that this mutation might be an early event in pancreatic oncogenesis. Therefore, in the present study, we evaluated whether benign pancreatic cysts are a precancerous condition as reflected by K‐ras mutation in pancreatic juice. Methods: Pancreatic juice was collected through endoscopic cannulation of the pancreatic duct. Analysis of the mutations was performed using the polymerase chain reaction–preferential homoduplex formation assay. Results: The frequencies and types of K‐ras point mutations and the rate of multiplicity of K‐ras mutations in patients with benign pancreatic cyst were the same as those with pancreatic cancer. Conclusions: Multiple K‐ras codon 12 mutations in the pancreatic juice of patients with benign pancreatic cysts are present as frequently as those with pancreatic cancer. These results indicate that patients with benign cysts may be at a high‐risk for the development of pancreatic cancer.     

The utility of intracystic glucose levels in differentiating mucinous from non-mucinous pancreatic cysts

BackgroundDifferentiating benign non-mucinous from potentially malignant mucinous pancreatic cysts is still a challenge. This study aims to improve this distinction with cyst fluid analysis.MethodsA cohort study of pancreatic cyst undergoing EUS/FNA was performed from a prospectively maintained database between 2014 and 2018 was performed.Results113 patients were analyzed (40 non-mucinous and 73 mucinous). For differentiating mucinous from non-mucinous cyst: intracyst glucose ≤41 mg/dl had a sensitivity of 92% and a specificity of 92%; positive predictive value (PPV) of 96 and negative predictive value (NPV) of 86. Glucose ≤21 mg/dl had a sensitivity of 88%, specificity of 97%, PPV of 98 and NPV of 81. CEA ≥192 ng/mL had a sensitivity of 50% and a specificity of 92%; PPV of 92 and NPV of 50. Glucose ≤21 mg/dl or CEA ≥192 ng/mL combined had a sensitivity of 93%, specificity of 92%, PPV of 96 and NPV of 87 (Fig. 1, Table 1).ConclusionIntra-cyst glucose levels (≤41 mg/dl) outperforms classic CEA testing for differentiation of mucinous from non-mucinous pancreatic cysts. It was found to be an excellent diagnostic test with an AUC of 0.95 (95% CI: 0.81, 0.97).     

Lymphoepithelial cyst in the lung: a case report

An unusual endobronchial presentation of lymphoepithelial cysts (LECs) is described in a HIV-seropositive patient. The bilateral infrahilar cysts had followed an apparently benign course for 2 years. Bronchoscopy revealed an endobronchial mass occluding the anterior basilar segment of the left lower lobe. Biopsy resulted in emptying of the cyst and showed the typical pseudostratified columnar epithelium with intraepithelial lymphocytes of an LEC. This diagnosis should be considered in patients with HIV infection and pulmonary cysts on CT.     

Requirement of a single high-risk feature as an indication for EUS for the diagnosis of asymptomatic pancreatic cysts

Background and aimsEndoscopic ultrasound (EUS) is widely used to evaluate pancreatic cysts. Recent American Gastroenterological Association (AGA) guideline limits EUS for evaluation of cysts with at-least two high-risk features (size ≥ 3 cm, dilated main pancreatic duct or presence of a solid component). We have investigated the impact of this guideline on sensitivity of EUS for pancreatic cancer and the reduction of EUS procedures for pancreas cysts.MethodsEUS procedures performed between 2004 and 2015 and related patient records were retrospectively reviewed to determine the presence or absence of high-risk features, and for the results of fine needle aspiration cytology.ResultsTwo hundred ten patients (108 males) underwent EUS for diagnostic evaluation of pancreatic cysts. Four patients (1.9%), all with at-least one high-risk feature, were diagnosed with cytologically-proven pancreatic cancer. Only 2 patients with cancer had at-least two high-risk features that would have warranted EUS examination based on the new AGA guideline. The requirement for at-least two high-risk features would have decreased the number of EUS procedures by 91%, but reduced the sensitivity for pancreatic malignancy to 50%. If only one high-risk feature was required, EUS procedures would have been decreased by 67%, with a sensitivity of 100%.ConclusionLimiting EUS to patients with pancreatic cysts with 2 or more high-risk features may substantially reduce the sensitivity for pancreatic malignancy. Performing EUS in patients with at least one high-risk feature may substantially decrease the need of invasive procedures without reducing sensitivity for detecting malignancy.     

Lympho-epithelial cyst of the pancreas: a difficult diagnosis. About two cases

We report two cases of lymphoepithelial cyst of the pancreas discovered incidentally on imaging in two men aged 50 and 61 years. One cyst contained hyperdense spots on CT-scan and in this case the biochemical analysis of the cyst fluid revealed high level of CEA. The unilocular cysts measured 4 and 5 cm on the surgical specimen. On microscopic examination, the cysts were lined by squamous keratinized epithelium positive for CEA, with rare mucin-secreting cells, lining on lymphoid tissue. The lymphoepithelial cyst is a rare dysembryoplastic benign lesion of the pancreas difficult to diagnose before surgery. The presence of keratin plugs on imaging is inconstant and the biochemical analysis of the cyst fluid can mislead to a diagnosis of mucinous cystic tumour. Cytological and histological analysis of fine needle aspiration material is of diagnostic interest and can avoid surgical resection when patients are symptom-free.     

Lymphoepithelial cyst of the pancreas: report of a case

The aim of this report is to describe the clinical and pathological features of a lympoepithelial cyst of the pancreas and to recommend fine-needle aspiration biopsy for the differential diagnosis of this lesion. A 55-year-old man was incidentally diagnosed as having a pancreatic tumor by abdominal ultrasonography. A hypoechoic cystic lesion was detected on the surface of the pancreatic body. A computed tomography revealed a cystic lesion surrounded by a smooth, flat wall. Magnetic resonance imaging revealed that the lesion was a low-intensity mass on the T1-image and a slightly high-intensity mass on the T2-image. The lesion was diagnosed as a benign cystic tumor, and enucleation of the tumor was scheduled. The fine needle aspiration biopsy was performed after laparotomy, and cytology of the contents was negative for malignant cells. The postoperative pathological diagnosis was a lymphoepithelial cyst of the pancreas. This cyst is an unusual but benign mass that requires minimal surgery.