A huge mediastinal organizing hematoma causing reversal of atrial septal defect shunt flow.
ABSTRACT We report a case of a 46-year-old woman who presented with subacute exertional dyspnea and severe hypoxia. A large cystic mass compressing the right side of the heart along with right-to-left atrial shunt flow through an alleged atrial septal defect (ASD) were detected on echocardiography. CT scan of the chest and MRI of the heart revealed a loculated cystic mediastinal mass with hemorrhage measuring 5.5×8 cm compressing the right atrium and ventricle. The patient underwent cyst resection and primary closure of the ASD. This report illustrates a case of an unusual symptomatic pericardial mass compressing the right atrium and ventricle in a patient with an secundum ASD.
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Copyright © 2011 The Korean Society of Cardiology
A Huge Mediastinal Organizing Hematoma Causing
Reversal of Atrial Septal Defect Shunt Flow
Eun Kyoung Kim, MD1, Sang Chol Lee, MD1, Sung Bum Park, MD1, Silvia Park, MD1,
Sunha Bahng, MD1, Yeon Hyeon Choe, MD2 and Kiick Sung, MD3
1Division of Cardiology, Departments of Internal Medicine, 2Radiology and Center of Imaging Science, Cardiovascular Imaging Center and
3Thoracic and Cardiovascular Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
We report a case of a 46-year-old woman who presented with subacute exertional dyspnea and severe hypoxia. A large cys-
tic mass compressing the right side of the heart along with right-to-left atrial shunt flow through an alleged atrial septal de-
fect (ASD) were detected on echocardiography. CT scan of the chest and MRI of the heart revealed a loculated cystic medi-
astinal mass with hemorrhage measuring 5.5×8 cm compressing the right atrium and ventricle. The patient underwent cyst
resection and primary closure of the ASD. This report illustrates a case of an unusual symptomatic pericardial mass com-
pressing the right atrium and ventricle in a patient with an secundum ASD. (Korean Circ J 2011;41:97-100)
KEY WORDS: Mediastinal cyst; Atrial septal defect; Hematoma.
Received: May 20, 2010
Revision Received: June 8, 2010
Accepted: July 12, 2010
Correspondence: Sang Chol Lee, MD, Department of Internal Medi-
cine, Samsung Medical Center, Sungkyunkwan University School of Me-
dicine, 50 Irwon-dong, Gangnam-gu, Seoul 135-710, Korea
Tel: 82-2-3410-3868, Fax: 82-2-3410-3849
• The authors have no financial conflicts of interest.
cc This is an Open Access article distributed under the terms of the Cre-
ative Commons Attribution Non-Commercial License (http://creativecom-
mons.org/licenses/by-nc/3.0) which permits unrestricted non-commer-
cial use, distribution, and reproduction in any medium, provided the origi-
nal work is properly cited.
Pericardial masses usually do not cause any symptoms,
and come to medical attention as an incidental finding on
chest imaging modalities. This is a report on a case of an un-
usual symptomatic pericardial mass-like lesion in a patient
with an secundum atrial septal defect (ASD). As a result of
the compression of the right side of the heart, severe right to
left shunting of blood developed through the ASD. The pa-
tient presented with sub-acute hypoxia, exertional dyspnea
and reactive erythrocytosis similar to those in patients with
A 46-year-old woman who had undergone peripheral stem
cell transplantation for acute undifferentiated leukemia 1.5
years ago was admitted for operation of graft-versus-host dis-
ease of the eye. Prior to the operation, markedly decreased SaO2
and PaO2 were noted and hence a comprehensive re-evalua-
tion of her medical problems was performed.
The patient’s echocardiogram before undergoing the periph-
eral stem cell transplantation had revealed a small secundum
ASD with left-to-right shunt accompanied with mild right at-
rial enlargement and mild tricuspid regurgitation (Fig. 1). The
surgery for ASD had been planned after completion of the tr-
eatment for leukemia.
When the patient was admitted for the eye operation, she
presented with severe hypoxia (SaO2 79.8%, Qp/Qs 0.87)
and subacute dyspnea on exertion. On physical examination,
mild cyanosis of the lips and tachycardia were noted and no
other specific findings could be found. Peripheral blood sme-
ar showed erythrocytosis as a result of the prolonged hypox-
emia. But despite oxygen replacement, hypoxia could not be
corrected. Her electrocardiogram revealed sinus tachycardia.
The follow-up echocardiogram 1.5 years after the initial echo-
cardiogram revealed a huge pericardial mass which was com-
pressing the right atrium and ventricle almost completely (Fig.
2A). Using contrast echocardiography, the extra-cardiac mass
and compression of the right side of the heart due to it could
be clearly delineated (Fig. 2B). No flow was seen between the
mass and the heart or the vascular structures, and the direc-
tion of the shunt flow through the ASD had changed from
98 Huge Mediastinal Hematoma
left-to-right to right-to-left due to increased intra-cardiac pres-
sure in the right side of the heart as a result of the external com-
pression (Fig. 2C). Chest CT and MRI of the heart showed a
loculated cystic mediastinal mass with hemorrhage measur-
ing 5.5×8 cm compressing the right atrium and ventricle.
Axial T2 weighted MR image showed a dark fluid-fluid level
within the dependent portion of the mass (Fig. 3C).
Resection of the pericardial cystic mass and primary clo-
sure of the ASD were performed. The cyst was firmly adherent
to the anterior epicardium of the right side of the heart and
was filled with brownish fluid resembling the fluid inside an
old hematoma. The right atrium and ventricle were colla-
Fig. 1. Initial echocardiogram. Apical four-chamber view is showing an atrial septal defect (A and B). On color doppler echocardiogram, the
direction of the shunt flow through the septal defect is shown to be left-to-right.
Fig. 2. Follow-up echocardiogram. A: in apical four-chamber view, the pericardial cyst is compressing the right side of the heart (*) almost com-
pletely. B: contrast echocardiogram demonstrating the pericardial cyst compressing the right atrium and ventricle (*). Cystic mass does not show
enhancement of contrast. C: color doppler echocardiogram showing a huge pericardial cyst and an atrial septal defect. The direction of the shunt
flow (white arrow) through the septal defect is shown to be right-to-left.
Fig. 3. Chest CT and MRI of the heart. Coronal view of chest CT (A) shows a cystic lesion in the right pericardial space. A short axis cine im-
age view (B) demonstrates a compressed right ventricle (*) and an intact left ventricle. There is no communication between the mass and the
heart. Axial T2-weighted view (C) shows a dark fluid-fluid level within the dependent portion of the mass.
Eun Kyoung Kim, et al. 99
psed due to external compression (Fig. 4B). The diagnosis of
an organizing hematoma with thick fibrotic walls was con-
firmed on biopsy. After the removal of this cystic mass, there
was normalization of the right ventricular size and no remn-
ant shunt flow was seen on follow-up echocardiography. On
follow-up arterial blood gas analysis, SaO2 and PaO2 were
normalized and the patient did not have any signs and symp-
toms of congestive heart failure such as dyspnea or cyanosis.
This is an unusual case of a rare complication of a pericardi-
al cystic mass-which was initially thought to be a primary peri-
cardial cyst or a thymic cyst that had developed following che-
motherapy-where severe hypoxia was developed in a subject
with ASD. Most primary pericardial cysts are congenital an-
omalies. Other less common causes include benign thymic,
bronchogenic, enteric and thoracic duct cyst as well as malig-
nant cysts of thyroid, parathyroid, lymphoma, thymomas, ter-
atoma and seminoma.1)2) There has been a report on develop-
ment of a benign thymic cyst in the anterior mediastinum
following chemotherapy for non-Hodgkin’s lymphoma.3)
A rare cause of a pericardial cystic mass is an acute or ch-
ronic cystic hematoma as in the case presented here. Pericar-
dial cystic masses are usually asymptomatic and found inci-
dentally on routine chest X-rays. The clinical presentation de-
scribed includes chest pain, tachycardia, persistent cough,
dyspnea, cardiac arrhythmia and lower respiratory tract in-
fection.4-9) The symptoms can result from the pressure of the
mass on the adjacent organs.11) The pericardial masses have
also been associated with multiple complications including
right ventricular outflow tract obstruction, pulmonary steno-
sis related to extrinsic compression, torsion of a vascular pedi-
cle, subsequent development of ischemia-related lesion of
the cyst, spontaneous internal hemorrhage and tamponade,
partial erosion into the superior vena cava or the anterior wall
of the right ventricle. These masses can lead to constrictive
pericarditis and congestive heart failure, but it is unknown wh-
ether a particular size or position of the cyst corresponds
with a higher rate of complications.5)6)11-13) In the present case,
the pericardial cystic mass became large enough to compress
the right side of the heart and cause a rare complication due to
the reversal of the direction of the shunt flow through the ASD.
The direction and magnitude of the shunt through ASDs
are determined by the size of the defect and the relative com-
pliance of the ventricles. As a rule, left atrial blood is shunted
to the right atrium in the early phase of the disease. Most pa-
tients with ASD will have impaired exercise tolerance and
exertional dyspnea, but these symptoms may be well compen-
sated for years. If the right ventricle fails or its compliance de-
clines, the left-to-right shunting diminishes in magnitude and
right-to-left shunting may occur.14) In the present case, the ch-
ange in direction of the shunt flow developed due to increas-
ed pressure in the right side of the heart due to extra-cardiac
compression as a result of increased size of the pericardial
cystic mass. As a result, persistent hypoxia and cyanosis deve-
loped, which could be corrected by the resection of the cystic
Pericardial organizing hematoma can be subject to inter-
nal hemorrhage and consequent growth in size as seen in the
present case. As a result, our case presented with reversal in
the direction of the shunt flow through the ASD from left-to-
right to right-to-left. But even in other cases without any ac-
companying abnormalities of the heart, the heart can be com-
pressed due to external pressure resulting in a decrease in
the cardiac output and deterioration of the patient’s health.
Hence, the knowledge of such likely complications, especial-
ly in cases of hematologic malignancies such as acute leuke-
mia, is crucial for early detection and curative treatment.
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