Clinical and radiological feature of lymphoepithelial cyst of the pancreas

Lymphoepithelial cysts of the pancreas: case report and review of the literature

BACKGROUND

Lymphoepithelial cysts (LECs) of the pancreas are a rare type of true pancreatic cysts and represent an estimated 0.5% of all pancreatic cystic lesions. They are benign lesions and have no malignant potential. However, they are hard to differentiate from malignant lesions because their imaging and clinical presentation vary greatly. Seeing as these are benign lesions which are increasingly found incidentally during imaging for other indications, correct diagnosis is important to prevent unnecessary intervention and morbidity.

CASE REPORT

We report the case of a 41-year-old female who presented with abdominal discomfort, bloating and dyspepsia. An abdominal computed tomography (CT) showed a large mass in the left fossa. We describe the diagnostic and therapeutic measures taken in this case.

METHODS

We reviewed the literature for common features of the LEC. We grouped common imaging and histological features of the LEC of the pancreas to provide easily identifiable characteristics to facilitate diagnosis. For the review, we focused on papers, mostly case reports, presenting these common characteristics. We also reviewed the literature for key topics that should be taken into account when considering therapeutic interventions in a patient with a possible diagnosis of a LEC.

CONCLUSION

Cysts of the pancreas are increasingly identified due to widespread use and improved resolution of cross-sectional imaging. To obtain the correct diagnosis, it is sometimes necessary to combine advanced imaging, i.e. CT and MRI-imaging, and endoscopic ultrasound with fine needle aspiration (EUS/FNA), while CA 19-9 also has diagnostic value. We summarize all diagnostic characteristics in a table for ease of use. Furthermore we summarized possible therapeutic interventions.

Lymphoepithelial cyst of the pancreas: can common imaging features help to avoid resection?

BACKGROUND

Differentiation of cystic pancreatic neoplasms remains a challenging task for radiologists regarding the main aim of identifying malignant and premalignant lesions.

PURPOSE

The study aimed to compare the radiological features of lymphoepithelial cysts (LEC) with other cystic pancreatic lesions, which could help to differentiate them in order to avoid unnecessary resection.

MATERIAL AND METHODS

We retrospectively reviewed 10 cases of resected and histopathologically confirmed LECs during a 12-year period with available imaging studies; 20 patients with mucinous cystic neoplasms (MCN), 20 patients with branch-duct intraductal papillary mucinous neoplasms (BD-IPMN), and 20 patients with serous cystic neoplasms (SCN) were selected to serve as control groups. Imaging findings as well as clinical data were analyzed.

RESULTS

The following imaging morphology of LEC was identified: simple cystic appearance (20%) and mixed cystic-solid appearance (80%) with either a diffuse subsolid component (30%) or mural nodule(s) (50%). All lesions revealed exophytic location with a strong male predominance (9:1). MCNs occurred exclusively in middle-aged women, IPMN in both sexes showed slight male predominance (13:7), and SCN showed female predominance (5:15). Median patient age in LEC (48.5, IQR 47-54.5) was significantly younger compared to IPMN (p < 0.001) and SCN (p = 0.02). Unenhanced CT attenuation of LEC was higher than MCNs (p = 0.025) and IPMNs (p = 0.021), showing no significant difference to SCN (p = 0.343).

CONCLUSION

The present study provides key radiological features of LEC for the differentiation from other cystic pancreatic lesions such as increased CT attenuation in the unenhanced phase, absence of a connection to the main pancreatic duct (MPD), and exophytic location. In addition to these imaging features, clinical data, such as male predominance in LEC, must be considered for the differentiation of cystic pancreatic lesions.

Pulmonary lymphoepithelial cyst with no prior HIV infection: A case report

Most lymphoepithelial cysts (LECs) occur in the salivary glands and are considered one of the autoimmune syndromes caused by the human immunodeficiency virus (HIV). In this report, we present a case of pulmonary LEC without prior HIV infection, paying special attention to radiographic features. A chest radiograph revealed an oval mass with a smooth surface, localized in the left lower lung field, which was in direct contact with the diaphragm. Computed tomography showed an oval homogenous mass with a smooth surface in the lower left lobe. Further, magnetic resonance imaging demonstrated that the mass was a homogeneous internal structure with a smooth surface and a slightly high signal in T2-weighted images and a slightly low signal in T1-weighted images. Surgical resection was performed, and pathological examination confirmed the diagnosis of a pulmonary LEC. To the best of our knowledge, no cases of pulmonary LECs without prior HIV infection have been reported in the literature to date, therefore, the case presented here is considered very rare and informative.

Imaging features and pathological evaluation by EUS-FNA enable conservative management in patient of lymphoepithelial cyst of the pancreas: a case report

Pancreatic lymphoepithelial cysts (LECs) are rare cystic lesions filled with a keratinous substance and lined by squamous epithelium with underlying lymphoid tissue. Because pancreatic LECs are entirely benign, correct preoperative diagnosis is important to avoid unnecessary surgery. However, the imaging features of pancreatic LECs are not specific and preoperative diagnosis has proven difficult. A pancreatic mass was incidentally detected through abdominal ultrasonography in a 63-year-old male presenting without any symptoms. Computed tomography showed an exophytic cystic lesion in the pancreatic head. The lesion had heterogeneous high signal intensity with partial low intensity on T2-weighted magnetic resonance imaging (MRI) and high signal intensity on diffusion MRI. Endoscopic ultrasound (EUS) examination showed an encapsulated cystic lesion with relatively homogenous and highly echoic contents. EUS-guided fine-needle aspiration (EUS-FNA) revealed caseous appearance and rare fragments of apparently benign squamous epithelium on a background of keratinous debris, cyst contents, and scattered lymphocytes. We diagnosed a pancreatic LEC and opted for conservative management without surgery. Pathological evaluation based on images obtained through EUS-FNA showed macro- and microscopic features that were critical to determining the management strategy. In conclusion, the imaging and pathological features of pancreatic LECs can inform preoperative diagnosis, which may enable conservative management.

A Rare Presentation of Pancreatic Lymphoepithelial Cyst: A Case Report and Review

Pancreatic lymphoepithelial cyst (LEC) is a rare, benign collection of keratinizing squamous epithelial cells encapsulated by lymphoid tissue. Because of its limited data and nonspecific features that can mimic malignant lesions, LECs can lead to unnecessary operations. A 62-year-old male with a known pancreatic mass presented with abdominal pain. CT scan showed an increased mass in the pancreatic head, and endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) revealed “rare fragments of benign-appearing squamous epithelium in a background of keratin debris, cyst contents, and scattered lymphocytes,” consistent with a lymphoepithelial cyst. Pancreatic LEC is an extremely rare lesion that comprises of only 0.5% of all pancreatic cysts. EUS-FNA has become the mainstay for diagnosing pancreatic LECs. Given the slow growing and benign nature, conservative management and observation is adequate for pancreatic LECs with excellent long-term outcome. With increasing number of imaging ordered by clinicians, it is anticipated that there will be a greater number of incidental pancreatic LECs detected. Thus, EUS-FNA should be utilized more frequently to help distinguish benign pancreatic LECs from premalignant or malignant lesions to avoid surgery.

Lessons learned from 29 lymphoepithelial cysts of the pancreas: institutional experience and review of the literature

BACKGROUND

Lymphoepithelial cysts (LECs) are rare pancreatic cystic lesions. Since LECs are benign, preoperative diagnosis is important to differentiate from a cystic neoplasm and avoid unnecessary surgery. The aim of this study was to identify clinical, radiographic and cytopathologic features associated with LECs.

METHODS

A retrospective review was performed of patients diagnosed with LEC between 1995 and 2017 at our hospital. Clinicopathologic and radiographic imaging features were documented.

RESULTS

Of 29 patients with pancreatic LEC, 22 underwent surgical resection. The majority were male (n = 24) with a median age of 55 years (range, 21-74). During the evaluation, all patients underwent a CT, with endoscopic ultrasound (EUS) guided fine needle aspiration (FNA) biopsy (n = 22) and/or MRI/MRCP (n = 11) performed in a smaller number of patients. A combination of exophytic tumor growth on imaging and the presence of specific cytomorphologic features on the EUS-FNA cytology biopsy led to the correct diagnosis of LEC and prevention of unnecessary surgery in 7 patients.

DISCUSSION

Differentiating LECs from premalignant pancreatic cystic neoplasms remains difficult. Findings of an exophytic growth pattern of the lesion on abdominal imaging and the presence of specific cytomorphologic features in the EUS-FNA biopsy could help clinicians diagnose LEC preoperatively.

Pancreatic Lymphoepithelial Cysts Diagnosed with Endosonography-guided Fine Needle Aspiration

Although lymphoepithelial cysts (LECs) of the pancreas are benign lesions, most of them have been treated with surgical resection due to diagnostic difficulty. We report a 66-year-old woman diagnosed with pancreatic LECs. Abdominal ultrasound revealed two masses in the pancreas, which were not visible on the abdominal computed tomography. In an abdominal magnetic resonance imaging, pancreas lesions showed solid tumors, which revealed a low signal intensity on T1-, moderate high signal intensity on T2 weighted images, and homogeneous delayed enhancement in the portal venous phase. Endosonography (EUS) revealed two hypoechoic round masses measuring 1.5 cm and 4.5 cm in the body and tail of the pancreas, respectively. EUS-guided fine needle aspiration (FNA) revealed squamous cells, amorphous keratinous debris, and lymphocytes. The patient was diagnosed with LECs of the pancreas. For the duration of the follow-up period of two years, imaging studies were unchanged. EUS-FNA is useful in making a definite diagnosis and avoiding unnecessary surgery. This is the first case of pancreatic LECs diagnosed with EUS-FNA in Korea.

Rare Tumors and Lesions of the Pancreas

There are a few entities that account for most solid and cystic masses of the pancreas. The pancreas harbors a wide array of diseases, including adenocarcinoma, and its variants, such as anaplastic and adenosquamous carcinoma. Other neoplasms include acinar cell carcinoma, solid pseudopapillary tumor, and sarcomas. Benign lesions include hamartomas, hemangiomas, lymphangioma, and plasmacytoma. Isolated metastases include renal cell carcinoma, melanoma, and other carcinomas. Benign inflammatory conditions, such as autoimmune pancreatitis and groove pancreatitis can also mimic solid neoplasms of the pancreas.

Lymphoepithelial cyst of pancreas: spectrum of radiological findings with pathologic correlation

PURPOSE

The purpose of the study was to investigate imaging features as well as pathologic and clinical findings of lymphoepithelial cyst (LEC) of pancreas.

MATERIALS AND METHODS

Ten patients with surgically resected and pathologically proven LEC, found in a single institution database between 2000 and 2015, were evaluated in a retrospective fashion. Patients' demographics, clinical presentation, co-morbidities, imaging features, cytology and histopathology results, and serum/aspirate biomarkers levels were recorded.

RESULTS

Eighty percent of patients were male with median age of 59. All lesions were exophytic, with median size of 36 mm. 80% were classified as complex cystic lesions, showing enhancing septa or enhancing rim without measurable enhancing solid component. 80% were located in tail or body. In one patient with MRI, the lesion was mildly T1 hyperintense and markedly T2 hyperintense. All cases were anechoic or hypoechoic on EUS, and majority of them showed posterior acoustic enhancement. Of patients with available fluid aspirate analysis, 3 out of 4 had CEA level > 192 ng/mL and 1 out of 3 had elevated (>250 IU/ml) amylase level. Four out of 7 patients had elevated serum CA 19-9 levels (>37 U/mL); one patient with a value of 361 U/mL had co-existing pancreatic adenocarcinoma.

CONCLUSION

Round shape, mild complexity, and exophytic location in pancreatic body and tail can be suggestive of LECs. These features however are not specific and may be seen with other cystic pancreatic lesions. CT findings should be used in conjunction with EUS, cytology, and tumor marker studies to secure the diagnosis of LEC.

An Unusual Suspect: Lymphoepithelial Cyst of the Pancreas

Lymphoepithelial cysts (LECs) of the pancreas are benign, rare pancreatic cysts that are found predominantly in men. These cysts can present as a diagnostic conundrum given their rarity and difficulty of distinguishing these cysts from those with malignant potential. We present an incidental case of a LEC in a middle-aged man.

Morphological differentiation and follow-up of pancreatic cystic neoplasms using endoscopic ultrasound

Endoscopic ultrasound (EUS) is a key modality for the evaluation of suspected pancreatic cystic neoplasms (PCNs), as the entire pancreatic gland can be demonstrated with high spatial resolution from the stomach and duodenum. Detailed information can be acquired about the internal contents of the cyst(s) [septum, capsule, mural nodules (MNs)], its relation with the main pancreatic duct (MPD), and any parenchymal changes in the underlying gland. PCNs comprise true cysts and pseudocysts. True cysts can be neoplastic or nonneoplastic. Here, we describe serous cystic neoplasm (SCN), mucinous cystic neoplasm (MCN), and intraductal papillary mucinous neoplasm (IPMN) as prototype neoplastic cysts, along with nonneoplastic lymphoepithelial cysts (LECs).

Lymphoepithelial cyst of the pancreas mimicking malignant cystic tumor: report of a case

Lymphoepithelial cysts of the pancreas are a type of true cyst that can mimic pseudocysts and cystic neoplasms. They are very rare, non-malignant lesions that are unilocular or multilocular cystic lesions lined predominantly by mature squamous epithelium and surrounded by non-neoplastic lymphoid elements. We, herein, present a patient with a cystic pancreas tumor mimicking a malignant cystic neoplasm. The patient was admitted with upper abdominal discomfort. Computed tomography showed a 64×39 mm cystic mass in the pancreas tail. She underwent distal pancreatectomy and splenectomy. In the fluid analysis of the pancreas cystic mass, the CEA and CA19-9 were 618 ng/ml and 3.9 U/ml, respectively. The resected pancreas specimen showed a 6.5 cm-sized cyst the pancreas tail. The cyst was well circumscribed and multilocular. The final pathology report of the resected pancreas specimen noted that the cyst was multilocular, and the cyst lining was showing stratified squamous epithelium covering the lymphoid tissue (containing lymphoid follicles), which was consistent with a lymphoepithelial cyst. The patient recovered uneventfully from surgery and has been doing well for the past 3 months. A differential diagnosis of cystic pancreatic lesions is important. We suggest that lymphoepithelial cysts, although very rare, may be included in the differential diagnosis of cystic pancreatic tumors.