CAS CLINIQUE/CASE REPORT - Lebanese Medical Journal

CAS CLINIQUE/CASE REPORT
EPIDERMOID CYST OF THE SPLEEN : CASE REPORT
http://www.lebanesemedicaljournal.org/articles/57-4/case1.pdf
Elias F. EL-KHOURY 1 , Maroun C. SOUAIBY 1 , Georges P. AFTIMOS 2
El-Khoury EF, Souaiby MC, Aftimos GP. Epidermoid cyst of
the spleen : Case report. J Med Liban 2009 ; 57 (4) : 268-270.
A B S T R A C T: Splenic cysts, very rare pathologies, are
classified into parasitic and the highly uncommon, non
parasitic cysts. Based on the presence or absence of an
epithelial lining wall, the latters are classified into true
cysts and false cysts. We present a case of a 23-yearold
male who presented to our clinic with a severalmonth
history of abdominal discomfort that was due
to the compressive effect of a huge nonparasitic true
splenic cyst.
INTRODUCTION
Splenic cysts are uncommon entities with an incidence
of only 0.5%-2.0% of the population [1]. They are either
parasitic (usually hydatid cysts) or nonparasitic (true cysts
with epithelial lining or more commonly false cysts).
We report a case of a large splenic epidermoid cyst, a
rare type of true nonparasitic splenic cyst.
CASE
A 23-year-old male presented to our clinic with a severalmonth
history of abdominal discomfort and a sensation
of fullness in his left upper abdomen. There was a vague
history of trauma.
Physical examination revealed a large, smooth, nontender
mass occupying the left hypochondrium. Routine
screening investigations (urinalysis and complete blood
count) were normal. Serologic tests were negative for parasitic
infection.
Abdominal CT scan showed a well defined 22.5 x
16.5 cm sized splenic mass, displacing the stomach to the
right (Fig. 1). The patient received Pneumovax and was
scheduled for splenectomy in two weeks. At surgery,
a very large cyst of the spleen occupying the entire left
upper abdomen, adherent to the left diaphragm, tail of the
pancreas and gastric fundus was found. Prior to splenectomy,
1500 ml of reddish fluid were evacuated.
1 General Surgery Division, 2 Pathology Department, Notre-
Dame des Secours Hospital, Jbeil, Lebanon.
Correspondence to : Elias F. El-Khoury, MD. General
Surgery Division. Faculty of Medical Sciences. Lebanese
University. Lebanon.
Tel. : +961 71 133447
e-mail : efkhoury@gmail.com
268 Lebanese Medical Journal 2009 • Volume 57 (4)
El-Khoury EF, Souaiby MC, Aftimos GP. Kyste épidermoïde de
la rate : A propos d’un cas. J Med Liban 2009 ; 57 (4) : 268-2 7 0 .
R É S U M É : Les kystes spléniques, pathologies très
rares, sont soit des kystes parasitaires soit, plus rarement,
non parasitaires. Ces derniers sont classés en
deux variétés selon la présence ou non d’un épithélium
: vrais kystes et faux kystes. On présente le cas
d’un jeune homme de 23 ans qui se plaignait d’un disconfort
abdominal pour plusieurs mois et qui s’est
avéré être dû à l’effet compressif d’un énorme vrai
kyste splénique.
The excised organ weighed 750 gm. The capsule was
whitish and firm. Microscopically, the sections showed a
picture of a true cyst composed of a wall lined by both
squamous and mesothelial cubic epithelia, consistent with
the diagnosis of an epidermoid cyst of the spleen (Fig. 2).
The postoperative course was uneventful and the patient
was discharged home three days after the operation.
DISCUSSION
Andral, in 1829, found a splenic cyst at autopsy and was
the first to report it. It is a very rare pathology, with an
incidence of only 0.5%-2.0% of the population [1]. Pean,
in 1876, performed the first successful splenectomy for a
splenic cyst. Splenic cysts are classified as parasitic or
nonparasitic. The majority of splenic cyts are parasitic
and due to Echinococcus granulosus infestation particu-
FIGURE 1
Well defined 22.5 x 16.5 cm sized splenic mass,
displacing the stomach to the right.

FIGURE 2
True cyst composed of a wall lined by squamous (Right) and mesothelial cubic (Left) epithelia.
larly in endemic areas like the Middle East, Africa, South
America, and India [2]. Based on the presence or absence
of an epithelial lining wall, nonparasitic splenic cysts are
classified into true cysts (also called primary) or false
cysts (also called secondary or pseudocysts).
True cystic tumors include hemangiomas, lymphangiomas,
epidermoid and dermoid cysts. Of these, hemangiomas
are the most common and dermoid cysts the
least. False cysts result from trauma, hemorrhage or infarction
and they are more common than true cysts. A
history of trauma can be obtained in most people with
splenic pseudocysts ; however, careful questioning can
uncover a history of trauma in many patients with true
cysts, as in our patient. It is likely that this is coincidental
and not causal.
Epidermoid cyst of the spleen is a primary nonparasitic
splenic cyst. If even remnants of an epithelial lining are
identified, the cyst should be classified as epidermoid.
Its true origin is not clear. These cysts can originate from
the invagination of splenic capsular mesothelium during
development with consequent fluid accumulation resulting
in cyst formation. Another explanation can be that
they originate from normal lymphatic spaces. Traumatic
minor splenic tear with mesothelial entrapment was also
postulated as an etiology [3]. Another theory suggested
that the epidermoid cyst is either of teratomatous derivation
or originates from inclusion of foetal squamous
epithelium rather than from squamous metaplasia of mesothelium
[4].
Splenic cysts lack typical clinical symptoms, and are
generally diagnosed when they enlarge and produce compressive
symptoms. Their enlargement can be due to the
proliferation and the secretions of the lining cells or to the
bleeding from the cystic wall [5], as well as to an osmotic
imbalance of the cystic fluid [3]. Pain is the most common
presenting complaint, usually in the left upper abdominal
quadrant.
Splenic cysts are usually solitary and unilocular. At ultrasonography,
epidermoid cysts appear as well-defined,
thin-walled anechoic lesions. At CT, epidermoid cysts
manifest as rounded, well-demarcated nonenhancing water
attenuation lesions. T 1- and T 2-weighted MRI images show
well-defined, rounded masses with signal intensity equal
to that of water in non-complicated cysts. The signal intensity
of those cysts may be altered by superimposed hemorrhage.
These radiological examinations are useful in distinguishing
true from false cysts, since internal septa are
more frequent in true cysts, while thick, fibrous, and calcified
parietal wall is typical of pseudocysts [6]. The final
diagnosis, however, is made at histology.
Complications of splenic cyst include rupture (with
peritonitis or hemorrhage) and infection (with abscess
formation leading to transdiaphragmatic perforation and
subsequent pleural effusion or empyema).
The risk of malignant transformation nearly does not
e x i s t .
CONCLUSION
Though splenic epidermoid cyst is an uncommon entity, it
should be considered in the differential diagnosis of an
abdominal mass. An attempt should be made to preserve
the spleen provided there is adequate parenchyma, otherwise
splenectomy is the rule.
Splenectomy treats the patient by eliminating the
symptoms and in asymptomatic patients it prevents complications,
because once perforation of the cyst or hemorrhage
occurs, mortality becomes noteworthy.
REFERENCES
1. Higaki K, Jimi A, Watanabe J et al. Epidermoid cyst of
the spleen with CA19-9 or carcinoembryonic antigen
productions : report of three cases. Am J Surg Pathol
1998 ; 22 : 704-8.
2. Macheras A, Misiakos EP, Liakakos T et al. Nonparasitic
splenic cysts : a report of three cases. World J Gastroenterol
2005 ; 11 : 6884-7.
3. Burrig KF. Epithelial splenic cysts. Pathogenesis of the
E. F. EL-KHOURY et al. – Epidermoid cyst of the spleen Lebanese Medical Journal 2009 • Volume 57 (4) 269

mesothelial and so-called epidermoid cyst of the spleen.
Am J Surg Pathol 1988 ; 12 : 275–81.
4. Lifschitz-Mercer D, Open M, Kushnir I, Czernobilsky B.
Epidermoid cyst of the spleen : a cytokeratin profile with
comparison to other squamous epithelia. Virchows Arch
1994 ; 424 : 213-6.
5. Morgenstern L. Nonparasitic splenic cysts : pathogenesis,
classification, and treatment. J Am Coll Surg 2002 ;
19 : 306-14.
6. Spencer NJB, Arthur RJ, Stringer MD. Ruptured splenic
epidermoid cyst : case report and imaging appearances.
Pediatr Radiol 1996 ; 26 : 871-3.
270 Lebanese Medical Journal 2009 • Volume 57 (4) E. F. EL-KHOURY et al. – Epidermoid cyst of the spleen