Imaging Pearls ❯ Pancreas ❯ Lymphoepithelial Cyst
|
-- OR -- |
|
- “Lymphoepithelial cysts are rare cysts lined with squamous epithelium and surrounded by lymphoid tissue. They typically affect men who are middle-aged or older and are exophytic with a higher CT attenuation compared with SCNs and MCNs. The reference standard for diagnosis is excision.”
Incidental Pancreatic Cysts on Cross-Sectional Imaging
Shannon M. Navarro et al.
Radiol Clin N Am 59 (2021) 617–629
- Overview
- Lymphoepithelial pancreatic cysts are rare lesions of unknown etiology
- First described in 1985
- Can occur anywhere in the pancreas
- Lined by kertanizing squamous epithelium
- Lymphoid tissue with germinal centers surrounds epithelial lining
- Contain keratinous debris and cholesterol clefts - CLINICAL FINDINGS
- Predominantly in men (M/F: 4/1)
- Predominantly in adulthood (mean age=56 and range=26 to 74 years)
- Often discovered incidentally
- May be associated with nonspecific abdominal symptoms
- May be multilocular (53%), bilocular, or unilocular (38%)
- Range in size from 2 to 13 cm - DIFFERENTIAL DIAGNOSIS
- Pancreatic pseudocyst
- Serous Cystadenoma
- IPMN
- Mucinous Cystic Neoplasm
- Extrapancreatic cysts impinging upon the pancreas
--- primary splenic cysts
--- splenic pseudocysts
--- cystic teratoma
--- gastrointestinal duplication cyst
--- mesenteric cyst - CT Findings
- Primarily visualized as a low-attenuation or cystic lesion arising from the pancreas
- Often appears exophytic
- May sometimes be misdiagnosed as cysts arising from other organs, such as spleen, kidney or mesentery
- Often unilocular and thin walled without internal septations or solid components - CT Findings
- CT appearance can be variable and overlap with other cystic neoplasms.
- Variety of less common findings have been reported:
--- small solid component
--- papillary projections
--- wall calcifications
--- thin wall enhancement
- “All lesions were well-defined and were exophytic off the pancreatic parenchyma. The lesion in Patient #2 had a unilocular cystic appearance, whereas the lesions in the other patients had a multilocular cystic appearance. The wall and septum of the cysts were enhanced. The contents of the cysts seemed homogeneous low density without enhancement. There were no solid portions within the cysts, calcification of the wall of the cyst, or dilatation of the main pancreatic duct, in any of the patients.”
Clinical and radiological feature of lymphoepithelial cyst of the pancreas Hirofumi Terakawa et al. World J Gastroenterol. Dec 7, 2014; 20(45): 17247-17253 - “A LEC is a rare benign lesion, which is lined with mature keratinizing squamous epithelium and surrounded by lymphoid tissue. It typically develops in middle-aged and elderly men, and it is localized to all parts of the pancreas with equal frequency. The mean size of these cysts is 47 mm. The cyst may be multilocular (60% of patients) or unilocular (40% of patients. Many patients with LEC have elevated serum levels of CA19-9. The cyst contents may vary from serous to caseous-like, depending on the degree of keratin formation.”
Clinical and radiological feature of lymphoepithelial cyst of the pancreas Hirofumi Terakawa et al. World J Gastroenterol. Dec 7, 2014; 20(45): 17247-17253 - “Because LEC is a benign lesion, it is often possible to select conservative treatment for ones without any significant symptoms if they can be diagnosed correctly. However, surgical resection is still commonly performed because it is difficult to distinguish them from other cystic lesions that require surgical intervention on account of their malignant potential. EUS-guided biopsy coupled with biochemical/tumor marker studies have recently helped to improve the diagnostic accuracy of pancreatic cysts. However, EUS-guided biopsy for cystic lesions of the pancreas is not generally performed in Japan because of the risk of the dissemination of tumor cells or the development of pseudomyxoma.”
Clinical and radiological feature of lymphoepithelial cyst of the pancreas Hirofumi Terakawa et al. World J Gastroenterol. Dec 7, 2014; 20(45): 17247-17253 - “Lymphoepithelial cysts (LECs) are very rare, non-malignant lesions which were first described by Lüchtrath and Schriefers in 1985. LECs are true pancreatic cysts that are lined by squamous epithelium and surrounded by mature lymphoid tissue. Kavuturu et al. reported that in the 28 years since the first report of an LEC, 109 cases have so far been documented in the literature.”
Lymphoepithelial Cyst of the Pancreas Arumugam P et al. Case Rep Gastroenterol. 2016 Jan-Apr; 10(1): 181–192. - “Recent reviews documenting the demographic features of LECs indicate a strong male preponderance, with lesions of variable size distributed throughout the head, body, and tail of the pancreas. Approximately half of the patients present incidentally, with the remaining patients being associated with non-specific symptoms such as nausea, vomiting, diarrhea, abdominal pain, weight loss, and fatigue.”
Lymphoepithelial Cyst of the Pancreas Arumugam P et al. Case Rep Gastroenterol. 2016 Jan-Apr; 10(1): 181–192. - “It has been thought to be difficult to differentiate LECs from other pancreatic lesions, such as serous cystic neoplasms, mucinous cystic neoplasms, and intraductal papillary mucinous neoplasms, because the appearance of the LEC on imaging varies from patient to patient and sometimes is similar to other pancreatic lesions.LECs are benign and do not possess malignant potential, and, thus, an accurate identification of these lesions is important to avoid unnecessary intervention.”
Lymphoepithelial Cyst of the Pancreas Arumugam P et al. Case Rep Gastroenterol. 2016 Jan-Apr; 10(1): 181–192. - “LECs tend to be well demarcated from surrounding pancreatic and adipose tissue and are commonly spherical with a well-defined wall . Cases are often peripancreatic rather than intrapancreatic, and the cysts can be multilocular (60%) or unilocular (40%). LECs can range in size from 0.5 to 17 cm, although the mean size is usually around 4 cm .” Lymphoepithelial Cyst of the Pancreas Arumugam P et al. Case Rep Gastroenterol. 2016 Jan-Apr; 10(1): 181–192.
- “Lymphoepithelial cysts are rare (<0.5% of all pancreatic cystic lesions) benign pancreatic cystic neoplasms that are most commonly seen in elderly men between 50 and 70 years old. These lesions have no malignant potential and are usually an incidental finding seen on imaging studies performed for totally unrelated reasons, although patients can rarely present with non- specific symptoms of abdominal pain.”
Multidetector Computed Tomography in the Evaluation of Cystic Tumors of the Pancreas Siva P. Raman, Elliot K. Fishman (in) Cystic Tumors of the Pancreas: Diagnosis and Treatment Marco Del Chiaro, StephanL.Haas, RichardD.Schulick Editors © Springer International Publishing Switzerland 2016 - “Prospective diagnosis can be extraordinarily difficult, although these lesions do tend to be peripancreatic (abutting and invaginating into the pancreas) rather than being truly of pancreatic origin. If a lesion is suspected to be extrapancreatic, rather than arising from the pancreas itself, lymphoepithelial cyst (along with lymphangioma and pseudocyst) should be considered.”
Multidetector Computed Tomography in the Evaluation of Cystic Tumors of the Pancreas Siva P. Raman, Elliot K. Fishman (in) Cystic Tumors of the Pancreas: Diagnosis and Treatment Marco Del Chiaro, StephanL.Haas, RichardD.Schulick Editors © Springer International Publishing Switzerland 2016
- “Lymphoepithelial cyst (LEC) of the pancreas is a rare, non-neoplastic lesion composed of keratinizing squamous epithelial cells and lymphoid tissue. Prospective diagnosis of LEC remains challenging due to paucity of data in the literature, its non-specific imaging, and the presence of cytologic features that overlap with other cystic pancreatic lesions. Preoperative diagnosis of LEC is of considerable interest since it can spare the patient an unnecessary operation.”
Lymphoepithelial cyst of pancreas: spectrum of radiological findings with pathologic correlation Borhani, A.A., Fasanella, K.E., Iranpour, N. et al. Abdom Radiol (2017) 42: 877. doi:10.1007/s00261-016-0932-3 - “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.”
Lymphoepithelial cyst of pancreas: spectrum of radiological findings with pathologic correlation Borhani, A.A., Fasanella, K.E., Iranpour, N. et al. Abdom Radiol (2017) 42: 877. doi:10.1007/s00261-016-0932-3