Pulmonary Valve Papillary Fibroelastoma: A Case Report and Review of the Literature.
Cardiac papillary fibroelastomas (PFEs) are uncommon benign tumors of the endocardium. They are the third most common primary cardiac tumors after myxomas and lipomas, accounting for 7% of all primary cardiac tumors.
Before echocardiography was available, PFEs were found incidentally at autopsy or during heart surgery. Since the advent of echocardiography, however, the number of cases diagnosed during life has increased. Aortic and mitral valves are the most common sites for PFEs, followed by the tricuspid valve and endocardium.[3,4] Twelve cases of pulmonary valve PFE have been reported, but none were found using echocardiography. All of these lesions were discovered incidentally during autopsy or surgery. Bhagwandien et al reported the first case of pulmonary valve PFE diagnosed by transesophageal echocardiography and confirmed by surgical resection. We present an additional case report of pulmonary PFE diagnosed by echocardiography and confirmed by pathologic examination.
REPORT OF A CASE
A 62-year-old white woman presented to her physician following 3 episodes of transient blindness (amaurosis fugax) in her right eye. The episodes started with visual loss in her right eye that occurred at the time of strenuous exertion. The episodes lasted less than 1 minute. There were no associated headaches, dizziness, light-headedness, palpitations, or eye pain. Because of the transient nature of the episodes, embolic etiology was suspected and cardiac evaluation was indicated. There was no significant cardiac history or evidence of cardiac disease. Computed tomography showed a filling defect within the right ventricle with a 3cm anterior mediastinal mass. Magnetic resonance imaging and transesophageal echocardiography revealed a mobile mass (1.8 x 1.7 cm in greatest dimension) located on the ventricular aspect of the right pulmonary valve leaflet (Figure 1). The lesion moved with the pulmonary valve and prolapsed back and forth across the valve, suggesting a cardiac tumor. Because of the fronds of the lesion, vegetations could not be excluded. Excision of the valve mass with repair of the valve leaflet was done, and a biopsy of the anterior mediastinal mass was taken.
Gross examination of the lesion showed numerous and delicate papillary fronds, which were most easily recognized by examination under saline; the fronds had the appearance of a sea anemone (Figure 2). The fronds were soft, white to tan, and friable.
The tissue was fixed in formalin and routinely processed for paraffin sections. Sections were stained with hematoxylin-eosin, elastin van Gieson, and trichrome. Microscopic examination demonstrated a core of dense connective tissue surrounded by elastic fibers, smooth muscle cells, and loose connective tissue covered by a single layer of hyperplastic endocardial cells (Figure 3). The anterior mediastinal mass was diagnosed as thymoma, lymphocytic predominant type.
Cardiac PFE is a rare benign cardiac tumor that has an estimated incidence of 0.0017% to 0.33% in autopsy series and an estimated echocardiography incidence of 0.019% in 1 clinical series.[2,3] Approximately 80% to 90% of PFEs are found on the valvular endocardium. Papillary fibroelastomas are usually single, but multiple tumors have been reported.
The pathogenesis of PFE is unknown. Papillary fibroelastomas sometimes exhibit a surface lamination, a finding consistent with the concept of growth by successive organization of fibrin deposits. The papilliferous surface is considered to result from exposure to the hemodynamic stress of flowing blood.[1,4] Lambl excrescences origin was suggested, but most authors believe that PFE is a separate entity. Other theories suggest that PFEs represent neoplasms, hamartomas, and inflammatory nodules.[4,7]
The differential diagnosis of PFE includes other papilliferous lesions of the heart, such as myxomas, Lambl excrescences, bacterial vegetations, and organizing marantic (thrombotic) endocarditis.[6,8] Myxomas most frequently originate from the wall of the left or right atrium and are rarely located on the valve surface. Myxomas differ histologically from PFEs by the presence of vessels within papillae, polygonal myxoma cells, diffuse myxoid matrix background, and the absence of laminated elastic fibers.[4,8] Lambl excrescences cannot be differentiated from PFEs based exclusively on microscopic findings. Grossly, PFEs are larger and more gelatinous than Lambl excrescences, and they are present anywhere on valvular surfaces away from the lines of closure. Lambl excrescences are, by definition, at the sites of valve closure. The growth appearance of a PFE can mimic bacterial vegetations and marantic endocarditis, but microscopic evaluation will help in distinguishing between these entities.[4,8]
The literature contains a case report of aortic valve PFE coincident with a cystic tumor of the atrioventricular node. Our case showed coincident PFE and thymoma. The explanation of this association is uncertain.
More than 60% of PFEs are slow growing and asymptomatic. In recent years, PFEs have been implicated in several embolic states, which include cerebrovascular events, myocardial infarction, and pulmonary embolism.[2,3,11] Bhagwandien et al reported intermittent substernal chest pain associated with pulmonary valve PFE. The etiology of patient chest pain is still uncertain.
The identification of PFE is important because it represents a surgically correctable cause of cardiac embolic phenomena. Despite their benign histology, PFEs should be excised because of their embolic complications. Surface thrombus is common with these tumors, but warfarin administration is not a protective measure, since patients still present with transient ischemic attacks despite warfarin therapy. Emboli may originate either from fragments of the tumor or from a thrombus formed around the tumor. Papillary fibroelastoma is a friable tumor, and aggressive manipulation may result in fragmentation and further embolism.
In conclusion, PFE is an increasingly recognized cardiac tumor and should be considered in the differential diagnosis of any papilliferous heart lesion. Transesophageal echocardiography and magnetic resonance imaging are useful and highly accurate tools in the diagnosis of PFE. Prompt identification allows for surgical excision, which is seemingly curative, safe, and well tolerated.
[1.] Lund GK, Schroder S, Koschyk DH, Nienaber CA. Echocardiographic diagnosis of papillary fibroelastoma of the mitral and tricuspid valve apparatus. Clin Cardiol. 1997;20:175-177.
[2.] Howard RA, Aldea GS, Shapira OM, Kasznica JM, Davidoff R. Papillary fibroelastoma: increasing recognition of a surgical disease. Ann Thorac Surg. 1999;68:1881-1885.
[3.] 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;30:784-790.
[4.] Burke A, Virmani R. Tumors of the Heart and Great Vessels. Washington, DC: Armed Forces Institute of Pathology; 1996:47-52. Rosai J, ed. Atlas of Tumor Pathology; 3rd series, fascicle 16.
[5.] Bhagwandien NS, Shah N, Costello JM Jr, Gilbert CL, Blankenship JC. Echocardiographic detection of pulmonary valve papillary fibroelastoma. J Cardiovasc Surg. 1998;39:351-354.
[6.] Lee KS, Topol EJ, Stewart WJ. Atypical presentation of papillary fibroelastoma mimicking multiple vegetations in suspected subacute bacterial endocarditis. Am Heart J. 1993;125:1443-1445.
[7.] Boone SA, Campagna M, Walley VM. Lambl's excrescences and papillary fibroelastoma: are they different? Can J Cardiol. 1992;8:372-376.
[8.] Aretz TH. The heart. In: Sternberg SS, Antonioli D, Carter D, Milles S, Oberman HA, eds. Diagnostic Surgical Pathology. 3rd ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 1999:1238-1241.
[9.] Agiamy A, Mahdl L. Papillary fibroelastoma of the aortic valve coincident with a cystic tumor of the atrioventricular node [abstract]. Pathologe. 2000;21: 250-254.
[10.] Ayabe S, Hara K, Yamazaki I, Toda E, Tamura T. Slowly growing cardiac tumor: a case of fibroelastoma. J Cardiol. 2000;36:129-32.
[11.] Brown RD Jr, Khandheria BK, Edwards WD. Cardiac papillary fibroelastoma: a treatable cause of transient ischemic attack and ischemic stroke detected by transesophageal echocardiography. Mayo Clin Proc. 1995;70:863-868.
Accepted for publication January 17, 2001.
From the Departments of Pathology (Drs Saad and Bshara, and Ms Galvis) and Cardiothoracic Surgery (Dr Liddicoat), Allegheny General Hospital, Pittsburgh, Pa; and the Department of Pathology, St Agnes Healthcare, Baltimore, Md (Dr Dabbs).
Reprints: David J. Dabbs, MD, Department of Pathology, St Agnes Healthcare, 900 S Caton Bird, Baltimore, MD 21229 (e-mail: firstname.lastname@example.org).
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|Title Annotation:||benign endocardium tumor|
|Author:||Saad, Reda S.; Galvis, Colleen O.; Bshara, Wiam; Liddicoat, John; Dabbs, David J.|
|Publication:||Archives of Pathology & Laboratory Medicine|
|Date:||Jul 1, 2001|
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