Background
Papillary fibroelastoma (PFE) is the most common primary cardiac tumor
surpassing myxoma 1. PFEs typically occurred on
valvular surfaces and the vast majority is seen on the left side2. Right atrial nonvalvular PFEs were delineated in 14
cases and only two cases were described as having located on the Chiari
network (CN) 3-5. Although PFEs were generally
considered benign, PFE has a tendency
leading to syncope, chest pain, stroke, myocardial infarction, pulmonary
embolism 2. Here, we report a rare case of PFE arising
from the right atrial CN detected by transesophageal echocardiography
(TEE) with a previous 14-day headache history.
Case presention
A 54-year-old man with a previous vertebral aneurysm history was
admitted to our hospital presented with a 14-day headache. The patient
denied nausea, shortness of breath, palpitations, and vomiting. Physical
examination was unremarkable and the results of all routine laboratory
tests were within normal limits. However, routine bedside
echocardiography suggested an unidentified mass mimicking myxoma in the
right atrium.
Among further cardiac examinations, an electrocardiogram showed a normal
sinus rhythm. Transthoracic echocardiography revealed a mobile, sessile
mass in the right atrium without
obstructing the orifice of tricuspid valve. The subsequent
transesophageal echocardiography confirmed the presence of a
1.56cm×1.24cm mobile, sessile, irregular mass arising from the CN
(Fig.1) and showed no evidence of
patent foramen ovale.
Surgical resection was considered for avoiding potential dislodgement
and confirming diagnosis. The patient underwent a right atriotomy aided
by cardiopulmonary bypass, the base of the stalk and the full thickness
of the endocardium involved was excised. Grossly, the tumor was a
cauliflower-shaped, red-colored mass attached to the fibrous reticulum
between inferior vena cava and coronary sinus (Fig.2). Postoperative
beside echocardiography indicated complete excision of the tumor.
Histopathologic findings showed papillary fronds with central
hypocellular, avascular, hyalinized stroma covered by a single layer of
endocardial cells (Fig.3). Microscopic features were compatible with PFE
and the final diagnosis was a papillary fibroelastoma located on the CN
of the right atrium. The patient made an uneventful postsurgical
recovery and was discharged home. Three months later, the patient came
back to our hospital to accept the operation for clipping vertebral
aneurysm as clinicians recommended.
Discussion
Cardiac PFE is a benign tumor that predominates in adults, with a peak
incidence in the 7th decade of life. PFE usually
develop on the cardiac valves and only about 23% originate from
nonvalvular surfaces. More than 95% of PFEs arise in the left heart2. The CN is a fibrous reticulum resulting from
incomplete regression of the right valve of sinus venous and the septum
spurium, connecting different parts of the right
atrium6. PFE attached to the CN is extremely rare with
only two cases reported up to now. One case presented a PFE on the CN
found incidentally in an autopsy in 1992 and another case of infective
endocarditis on the CN has been reported in 2008 4,5.
In this case, we occasionally found a PFE located on the CN by
echocardiography with a 14-day headache history. With the increased use
of echocardiography and enhanced awareness of PFE, PFEs are diagnosed
more often in recent years and become the most common primary cardiac
tumor in adults 1. Echocardiography is a non-invasive
and convenient diagnostic technique and should be the first choice for
detecting suspected PFEs. TEE is extremely useful to preoperative
evaluation and decision-making of treatment, providing specific
delineation of the size, shape, location, mobility, and the presence of
stalk of neoplasms with high-resolution imaging 7. In
addition, TEE is capable of guiding the surgery intraoperatively and
evaluating the cardiac function postoperatively.
PFEs are associated with different embolic symptoms according to their
location in the heart. Tumors located in the left heart are usually
relevant to obstructive and embolic symptoms, and the most common sites
of embolization are cerebral, coronary, and systemic circulation.
Right-sided tumors mostly remain asymptomatic. However, the cases of
embolization to the pulmonary vessels leading to subsequent pulmonary
hypertension have been reported. The exact etiology behind the symptoms
remains unclear, whereas some researchers view that the embolization may
originate from the tumor fragments or a thrombus formed on the surface
of the tumor. In Vandergoten’s report, congenital patent foramen ovale
with right-to-left shunts may attribute to paradoxical embolisms from
the right-sided PFEs 2. Consequently, the right atrial
mass in our case seems to be irrelevant to the headache symptom without
any evidence of congenital anomalies.
Differential diagnosis of PFE encompasses myxoma, thrombi, vegetations,
strands, and giant Lambl’s excrescences 8. Clinical
data, blood cultures, laboratory tests together with echocardiographic
features may be useful to differentiate these lesions. But the ultimate
diagnosis depends on the characteristic histopathological features.
In our report, the patient was treated surgically and made an uneventful
postsurgical recovery. One study has shown that the tumor mobility is
the independent predictor of death 2. Surgery is
curative with an excellent long-term prognosis and a careful follow-up
echocardiogram is recommended for potential recurrence. If the patient
is not a surgical candidate, chronic anticoagulation with antiplatelet
agents or aspirin is usually suggested 2,8.
References
1. Tamin SS, Maleszewski JJ, Scott CG, et al. Prognostic and
Bioepidemiologic Implications of Papillary Fibroelastomas. J Am Coll
Cardiol 2015;65:2420-9.
2. Gowda RM, Khan IA, Nair CK, Mehta NJ, Vasavada BC, Sacchi TJ. Cardiac
papillary fibroelastoma: a comprehensive analysis of 725 cases. Am Heart
J 2003; 146:404–11.
3. Hakemi EU, Bero J, Sekosan M, Ansari A. Nonvalvular right atrial
papillary fibroelastoma. J Thorac Cardiovasc Surg 2013;145:e71-3.
4. Latif F, Peyton M, Laszik Z, Sivaram CA. Infective endocarditis of a
papillary fibroelastoma on Chiari network of right atrium: a case
report. J Am Soc Echocardiogr 2008;21:188.e3-4.
5. Wasdahl DA, Wasdahl WA, Edwards WD. Fibroelastic papilloma arising in
a Chiari network. Clin Cardiol 1992;15:45-7.
6. Loukas M, Sullivan A, Tubbs RS, Weinhaus AJ, Derderian T, Hanna M.
Chiari’s network: review of the literature. Surg Radiol Anat
2010;32:895-901.
7. Klarich KW, Enriquez-Sarano M, Gura GM, Edwards WD, Tajik AJ, Seward
JB. Papillary fibroelastoma: echocardiographic characteristics for
diagnosis and pathologic correlation. J Am Coll Cardiol 1997;30:784–90.
8. Sun JP, Asher CR, Yang XS, et al. Clinical and echocardiographic
characteristics of papillary fibroelastomas: a retrospective and
prospective study in 162 patients. Circulation 2001;103:2687-93.