Maligniteyi taklit eden belirgin endotelyal proliferasyon gösteren kistik splenik hamartoma: olgu sunumu

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Introduction
Splenic hamartoma is a benign uncommon lesion,
first described by Rokitansky in 1861 (1-5). There have
been cases over 100 so far (1). It has been also named as
splenoma and splenadenoma, hamartoma, hemangioma, lymphangioendothelioma, angiomatosis, hemangiomatosis, hymphangioma, hyperplastic nodule and
tumor-like congenital malformation (1-6). It has been
claimed that there have been several pathogenetic mechanisms such as congenital, neoplastic, posttraumatic and hamartomatous according to the pathogenesis
of the splenic hamartoma (1-6). It has been previously considered as splenoma and splenadenoma. Later
it has been claimed that the splenic hamartoma may
be a special form of a hemangioma/lymphangioma.
These suggestions have supported that this lesion can
be neoplastic. But, the most favorite suggestion related
to the pathogenesis of the splenic hamartoma is tumor-like congenital malformation that occurs as result
of the abnormal organization of the normal splenic
red pulp elements (1-3).
Although the splenic hamartoma is seen at every
age, it is frequently detected in older people (1-2). It
is usually asymptomatic and incidentally determined
during the autopsy, radiological studies and surgical
staging of Hodgkin disease.
Some complications like trombocytopenia and anemia can be shown due to sequestration of the hemapoetic cells in some patients with splenic hamartoma. Sometimes, the splenic hamartoma can undergo
cystic degeneration, in turn, constituting pseudocyst.
Pseudocyst appears as a complication in the splenic
hamartoma. The association of the pseudocyst and
the splenic hamartoma is rather uncommon. It may
hemorrhage inside the lumen and even rupture outside the lumen in some cases. Moreover, the prominent
endothelial proliferations in the splenic hamartoma
may constitute atypical features. So, these cases can
be misdiagnosed as malignant.
* Department of Pathology, Gulhane Military Medical Faculty
** Department of Pathology, Etimesgut Military Hospital
***Department of Surgery, Gulhane Military Medical Faculty
Reprint request: Dr. Armağan Günal, Department of Pathology, Gulhane
Military Medical Faculty, Etlik-06018, Ankara, Turkey
E-mail: armagangunal@hotmail.com
Date submitted: April 13, 2008 • Date accepted: August 10, 2008196 • September 2009 • Gulhane Med J Özcan et al.
Case Report
A 44-year-old female patient had been suffering
from nonspecific abdominal pain, weakness and fatigue for one year. There was not any trauma except for
the right nephrolitotomy operation, which was performed 14 years ago. The routine laboratory findings
were normal except for the anemia (hemoglobin: 9.0
gr/dL, hematocrit: 27.4%). The cystic mass that was
11 cm in diameter was determined in the upper pole
of the spleen during the abdominal ultrasonographic
and tomographic examinations (Figure 1). In turn,
splenectomy was performed. She was followed for 8
years and maintained her life healthy.
Figure 1. The magnetic resonance imaging appearance of the cystic
splenic hamartoma
Grossly, the spleen was 20x17x5 cm in size. There
was cystic mass in the upper pole of the spleen.
It was 11x10x10 cm in size and its wall thickness
ranged between 0.4 and 0.6 cm. In one side of the
cystic mass a solid brownish hamartomatous component was noticed protruding towards the cystic
lumen. This component was 6x2.5x2 cm in size,
and it contained focal microcystic areas. There was
abundant brownish granular material within the
cystic lumen. The spleen was normal at the other
sites (Figure 2).
Histopathologically, the cyst with thick fibrous
wall was not lining epithelium. The normal splenic
border and the luminal surface of the hamartoma
were surrounded with broad fibrous capsule. It consisted of the sinus like clefts and the cordons like
structures mimicking the normal spleen red pulp.
While lymphoid follicules were seen in the normal
spleen, they were not present in the hamartoma
(Figure 3A, 3B). The lymphocyte and macrophage
clusters were present inside the sinusoid like structures of the hamartoma (Figure 4). The cordons
of the hamartoma consisted of the polygonal cells
with eosinophilic cytoplasm and oval-round nucleus
Figure 2. The macroscopic appearance of the cystic splenic
hamartoma. Cystic lumen (in the right upper side), microcystic
and solid hamartomatous area (in the left side) and normal splenic
paranchyma (in the right bottom side)
Figure 3 A. Normal splenic paranchyma (in the left side), broad
fibrous capsule (in the middle area) and the splenic hamartoma (in
the right side) (H&E, x100) B. Splenic hamartoma (in the left side)
and cystic lumen (in the right side) (H&E, x100)Volume 51 • Issue 3 Cystic splenic hamartoma • 197
the hamartoma cannot be seen in the hemangioma.
Sometimes, these morphologic features may not be
helpful in the differential diagnosis of the problematic lesions. CD8, which immunohistochemically
stains splenic endothelial cells may be useful in the
differential diagnosis (4). The pseudocystic change
can also be seen in the hemangioma as result of the
cystic degeneration (1). Our case is clear and can be
easily differentiated from the hemangioma. The giant cell formations and pleomorphic features of the
endothelial proliferations in some areas may lead
to misdiagnosis. Therefore, these lesions have to be
closely followed because of the malignancy possibility. Our case was consulted. But, it was interpreted
as the undifferentiated carcinoma of the spleen. We
interpreted as the splenic hamartoma showing the
pseudocystic changes. Afterwards, we have closely
followed the patient for 108 months. The patient
Figure 5. Polygonal cells with eosinophilic cytoplasm and sinusoid
like clefts in the hamartomatous area (H&E, x400)
Figure 4. Lymphocyte and foamy macrophage clusters are shown
inside sinusoid like structures (H&E, x200)
Figure 6. Sinusoid like structures lined proliferating endothelial cells with
slight pleomorphic appearance and cystic enlargement (H&E, x200)
(Figure 5). There was slight pleomorphism in the polygonal cells. But, there was not mitotic activity. The
sinusoid like structures were lined by proliferating
endothelial cells with pleomorphic features. These
structures can demonstrate cystic enlargements in
some areas (Figure 6). These endothelial cells can demonstrate the reactive multinuclear features due to
degenerative changes. Therefore, these endothelial
cell proliferations can be misinterpreted as a malignant lesion (like undifferentiated carcinoma of the
spleen), especially, in the complicated cases. There
were focal hemosiderin pigment accumulations in
the hamartoma.
Discussion
Splenic hamartoma is an uncommon benign lesion that has been named in different ways. Splenic
hamartoma and hemangioma have been previously considered as the same lesions due to the similarity of the clinic and morphologic features (1-3).
But, the last studies have proven that these lesions
are different entities. They have to be distinguished
from each other (4). These lesions demonstrate the
macroscopic and microscopic differences. Splenic
hamartoma is homogen dark brownish lesion, while
the hemangiomas are white lesions that are usually
satellite scar in their center. The hemangioma consists of the small vascular spaces lined by flattened
endothelial cells and is surrounded by thin fibrous
tissue. Splenic hamartoma usually consists of red
pulp like cordons and sinus like clefts. The vascular spaces in the splenic hamartoma are uncommon
than the hemangioma. In addition to these differential features, while the big vascular structures
are found in the hemangioma, they are not seen in
the splenic hamartoma. The lymphocyte clusters in 198 • September 2009 • Gulhane Med J Özcan et al.
has continued her life in a healthy way without any
problem.
Splenic hamartoma is uncommon, and should be
distinguished from the primer hemangioma and malignant lesions of the spleen. The association of the
pseudocyst and splenic hamartoma is very uncommon as well (1). We considered that it emerged as
a complication in the background of the splenic hamartoma. It is necessary to be careful because the prominent endothelial proliferations in the sinusoid like
clefts and the slight pleomorphic polygonal cells in
the red pulp like cordons of the splenic hamartoma
can be confused with malignancy by mistake. These
histopathologic features should be evaluated in detail, and these patients should be closely followed.