Table of Contents
Definition / general | Essential features | ICD coding | Epidemiology | Sites | Pathophysiology | Etiology | Clinical features | Diagnostic criteria | Laboratory | Radiology description | Radiology images | Prognostic factors | Case reports | Treatment | Clinical images | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Cytology images | Sample pathology report | Differential diagnosis | Board review style question #1 | Board review style answer #1 | Board review style question #2 | Board review style answer #2Cite this page: Krogh K Lymphoepithelial cysts. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/pancreaslymphoepithelial.html. Accessed February 8th, 2023.
Definition / general
- Extremely rare, nonneoplastic, true cyst lined by squamous epithelium with abundant lymphoid tissue
- Histologically similar to branchial cleft cysts arising in the neck
- First described in 1985 (Pathologe 1985;6:217)
- No association with salivary gland lymphoepithelial cysts
Essential features
- Consists of a squamous epithelial-lined cyst with surrounding lymphoid tissue
ICD coding
- ICD-10: K86.2 - cyst of pancreas
Epidemiology
- Mean age 56 years, range 35 – 82 years, 80% male (Mod Pathol 2002;15:492)
- 0.5% of pancreatic cysts
- From 1985 to 2016, 109 cases described in the literature (JOP 2013;14:250)
Sites
- Occurs anywhere in pancreas (head, body or tail) or extrapancreatic location
Pathophysiology
- May occasionally develop from epithelial remnants in lymph nodes (Hum Pathol 1991;22:924) or from accessory spleen in pancreas (Mod Pathol 1998;11:1171)
Etiology
- Etiology is unclear; still debated whether lymphoepithelial cysts are derived from embryonic remnants or pre-existing tissues with acquired inflammatory change (Medicine (Baltimore) 2015;94:e1758)
- Another possibility notes similarity to Warthin tumors in which lymphoid cells have an affinity for ductal epithelia and can induce their growth (Adv Anat Pathol 2011;18:98)
Clinical features
- Presents with nonspecific symptoms such as abdominal pain or nausea; ~50% present incidentally (JOP 2013;14:250)
- Not associated with immunosuppression or autoimmune diseases
Diagnostic criteria
- Often diagnosed on fine needle aspiration by cytopathologist
- Can be difficult to differentiate preoperatively from other pancreatic cystic lesions
Laboratory
- Cyst fluid has elevated CA19-9 levels and occasionally elevated CEA levels (diagnostic pitfall) (Mod Pathol 2010;23:1467)
Radiology description
- On CT, enhancement often equivocal; can look similar to serous cystic neoplasms, mucinous cystic neoplasms and intraductal papillary mucinous neoplasms
- Imaging varies and is similar to other pancreatic lesions (JOP 2013;14:15)
Prognostic factors
- Benign, does not recur or progress
Case reports
- 49 year old male with weight loss and diarrhea (Dig Surg 2000;17:309)
- 56 year old male with pancreatic cyst incidentally detected on a CT scan (Case Rep Gastrointest Med 2016;2016:5492824)
- 60 year old male with lymphoepithelial cyst (Case Rep Gastroenterol 2012;6:604)
- 66 year old male with sebaceous glands within a lymphoepithelial cyst (Surg Case Rep 2016;2:98)
- 66 year old male with lymphoepithelial cyst (Indian J Surg 2010;72:427)
Treatment
- Resection is curative
Gross description
- Mean size 5 cm (range 1 – 17 cm)
- Often round and well demarcated from surrounding pancreas
- Either multilocular (60%) or unilocular (40%)
- Cysts contain serous or cheesy keratin-containing material
Microscopic (histologic) description
- Unilocular or multilocular cyst lined by squamous epithelium (nucleated or anucleated), with lymphocytes (intervening T lymphocytes) and germinal centers in the wall
- Combinations of squamous lining with other epithelial types (i.e. simple columnar) have been reported
- Lymphoid tissue, often a dense band
- With or without keratinous debris
- Occasional solid lymphoepithelial islands, rarely mucinous goblet cells
- Rare sebaceous differentiation, keratin granulomas, cholesterol clefts, multinucleated giant cells and foamy histiocytes may be present
Microscopic (histologic) images
Cytology description
- Numerous anucleated squamous cells, amorphous debris (Cancer 2006;108:501)
- May have mildly atypical mucinous glandular and parakeratotic epithelium
- Rare benign nucleated cells, usually no lymphocytes
Cytology images
Sample pathology report
- Pancreas, cyst, excision:
- Lymphoepithelial cyst
Differential diagnosis
- Clinical differential diagnosis includes mucinous cystic neoplasms, intraductal papillary mucinous neoplasm (IPMN), intraductal oncocytic papillary neoplasm (IOPN) (but different histologically)
- Histological differential diagnosis:
- Dermoid cyst: has dermal appendages microscopically; younger mean age, prominent mucinous cells or respiratory mucosa
- Epidermoid cyst in intrapancreatic spleen: surrounded by splenic tissue (Acta Pathol Jpn 1991;41:916)
- Squamoid cysts: small, without lymphoid tissue
- Lymphangioma: has endothelial linings, positive for endothelial and lymphatic markers; small aggregates of lymphoid tissue rather than dense band
- Pseudocyst: no epithelial lining, no lymphoid stroma
Board review style question #1
Board review style answer #1
B. This lesion does not undergo malignant transformation
Comment Here
Reference: Lymphoepithelial cysts
Comment Here
Reference: Lymphoepithelial cysts
Board review style question #2
Which of the following statements about this pancreatic lesion is true?
- This lesion is the most common cystic lesion of the pancreas
- This lesion is caused by immunosuppression or autoimmune dysfunction
- Foamy histiocytes can be present
- This lesion is associated with salivary gland lymphoepithelial cysts
Board review style answer #2