Lymphoepithelial cysts

Pancreas
Cysts
Lymphoepithelial cysts

Authors: Katrina Krogh, M.D., Guang-Yu Yang, M.D., Ph.D.

Editor-in-Chief: Debra Zynger, M.D.

Topic Completed: 4 April 2019

Minor changes: 6 March 2020

Copyright: 2002-2020, PathologyOutlines.com, Inc.

PubMed Search: Lymphoepithelial cysts[TIAB] pancreas

Page views in 2019: 1,615

Page views in 2020 to date: 703

Table of Contents

Cite this page: Krogh K Lymphoepithelial cysts. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/pancreaslymphoepithelial.html. Accessed May 29th, 2020.

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)

Radiology images

Images hosted on other servers:

Large cystic mass

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

Clinical images

Images hosted on other servers:

Intraoperative view

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

Gross images

Images hosted on other servers:

Well demarcated cysts

Cyst with papillary projection

Pancreas tail

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

Contributed by Katrina Krogh, M.D.

Lymphoepithelial cyst of the pancreas

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

Images hosted on other servers:

Squamous  epithelium,
keratinaceous debris
and lymphocytes

Squamous cells with rare lymphocytes

Keratinaceous debris

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

Which of the following statements is true about the following pancreatic lesion?

This lesion is more common than pancreatic mucinous adenocarcinoma
This lesion does not undergo malignant transformation
This lesion is found in females more commonly
CEA is never elevated in cyst fluid

Board review answer #1

B. This lesion does not undergo malignant transformation

Comment Here

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 answer #2

C. Foamy histiocytes can be present

Comment Here