Transcript PowerPoint 프레젠테이션

Lymphoepithelial Cyst with Sebaceous Differentiation (Sebaceous Lymphadenoma) of the Pancreas,
Dermoid Cyst or Not ? - A Case Report and Review of Literatures
Dae Kyum Kim, Sang Ik Noh, Jin Seok Heo, Jae Hyung Noh,Tae Sung Sohn, Seong Ho Choi, Yong Il Kim, GeungHwan Ahn*
Department of Surgery and Diagnostic Pathology*, Samsung Medical Center, Sungkyunkwan University, School of Medicine, Seoul, Korea
Introduction
4. Pathologic Findings
‘lymphoepithelial cyst’ for these interesting cyst.
•Classification
•Gross examination (Fig.2)
Lymphoepithelial cysts (LECs) of the pancreas are rare, with the
literature containing only 40 documented examples of this entity,
which are distinctive lesions characterized by the presence of a
mature, keratinizing squamous lining surrounded by lymphoid
tissue. Among these rare cysts, the case with sebaceous
differentiation, so-called unilocular cystic sebaceous
lymphadenoma is extremely rare. Sebaceous differentiation is not
revealed usually in LECs, so that it may be confused with dermoid
cyst that usually shows sebaceous differentiation . We have
experienced this rare cyst and review it in surgico-pathological
aspect.
Case
A unilocular cyst measured 3X2X2 cm in greatest dimension and
contained bright yellow cheesy, greasy tiny oval materials and
whitish keratin. The wall was relatively rough. No communication
with pancreatic duct was found.
•Differential diagnosis in the squamous lined cysts
LECs are seen predominantly in men and in adulthood (mean age,
56 years). They may occur at any site of the pancreas. LECs may be
multilocular or unilocular, and are characterized by stratified
squamous epithelium surrounded by dense lymphoid tissue such
as germinal centers.
Mass
Pancreas
Spleen
1.Brief History
A 70 year-old man presented with a two month history of
postprandial upper abdominal pain. He had a history of heavy
alcoholic drinking while he was young but had no history of
abdominal trauma. Physical examination showed right upper
quadrant tenderness. Chest X-ray, EKG, and laboratory data
including cardiac and pancreatic enzymes were normal. On an
ultrasonographic study showed multiple hepatic simple cysts and
mild pancreatic ductal dilatation. CT and ERCP were performed.
2. Radiologic Findings
Fig.2 Gross finding. The
cyst was unilocular
•Microscopic examination (Fig.3)
The wall was lined by keratinising squamous epithelium which was
surrounded by dense lymphoid tissue with germinal centers. A few
clusters of well-formed sebaceous glands were found beneath the
squamous epithelium. There was no hair follicle and sweat grand.
On immunohistochemical staining, the epithelial lining was positive
on keratin stain, inner epithelial cell contained PAS, D-PAS and
mucicamine positive material.
•CT finding (Fig. 1, Left)
A 2.7 cm sized protruding cystic mass with low density was
revealed in the tail of the pancreas. There was no definite solid
portion in the mass but internal enhancing septa were showed.
Pancreatic cystic neoplasm was suggested. In liver, multiple simple
cysts were identified.
Dermoid cysts occur in younger age group (mean age, 23 years),
and there is no gender prominence. Mucinous epithelium,
respiratory type mucosa, and sebaceous units are more readily
identifiable, and they may contain hair follicles. Subepithelial
lymphoid tissue is not a feature.
Accessory-splenic epidermoid cysts tend to be detected at an
younger group (mean age, 37 years) than LESs. There is no gender
prominence and microscopically, the presence of splenic red pulp
is diagnostic.
•LEC with sebaceous differentiation (LECSD)
LECSD was described by Fitko and co-workers in 1994. Like our
case, the possibility of a dermoid cyst was considered because of
presence of sebaceous glands. However, it is precluded by lack of
hair follicles and sweat gland and the presence of dense lymphoid
tissue. LECSD has been also reported in other organs, such as skin
and salivary gland. That may be owing to multipotentiality of
germinative cells of squamous epithelium.
•Pathogenesis
Germinal centers
The histopathogenesis of LECs is unclear. There are four proposed
mechanisms.
Squamous
epithelium
1. Development from epithelium remnants in lymph node.
•ERCP finding (Fig. 1,Right)
2. Squamous metaplasia in the pancreatic duct that undergo
cystic transformation.
Pancreatic duct was normal.
3. Some form of teratoma
Sebaceous gland
Fig. 3 Microscopic findings. Dense germinal centers and squamous
epithelium, H & E X50 (Left). Sebaceous differentiation, H & E X100
(Right).
Liver cyst
Cystic lesions of the pancreas can be histologically classified into
several categories including pseudocyst, congenital true cyst,
acquired true cyst, and cystic neoplasm. True cysts are
characterized by epithelial lining, in which there are 3 types of
morphologically similar lesions that may presents as ‘squamous
cysts’; LECs, dermoid cysts, and accessory-splenic epidermoid
cysts.
Mass
4. Development from misplaced brachial cleft tissue.
•Treatment
Surgical resection is only treatment. LECs can be cured completely
by resection. As previously described, surgery is important to
identification and early removal of pancreatic cystic neoplasm.
5. Postoperative course
Pancreatic duct
The patient was discharged on 9th postoperative day. He was
followed up 12-month postoperatively and no recurrence was
noted.
Discussion
Fig. 1 CT and ERCP findings
3. Operation
A laparotomy was performed with impression of pancreatic cystic
neoplasm. In the tail of the pancreas, 3 cm sized protruding cystic
mass was found. The cyst was unilocular and there was no
infiltration. Distal pancreatectomy was performed.
Conclusion
•History
Lymphoepithelial cyst(LEC) of the pancreas is one of the cysts that
are recently described as a disease entity. In 1985, Luchtrath and
Schriefers described a multilocular cyst of the pancreas
histologically similar to the so called branchiogenic cysts that occur
in the neck. In 1987, Truong and co-workers proposed the name
•LECSD is curable with surgical resection.
•It is extremely rare but may be considered a distinct
entity in the cystic lesions of the pancreas.