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Papillary
fibroelastoma (PFE) is the most common valvular tumour and the second
cardiac benign tumour after myxoma.
These
are slow growing
and asymptomatic
lesions
seen at any age.
Diagnosis in infants and children should be done carefully as it
may be confused with other lesions at that age.
Despite their
benign histology, PFEs should be excised because of their embolic
complications. Emboli may originate either from fragments of the tumor
or from a thrombus formed around the tumor.
At present, asymptomatic patients are
most frequently diagnosed by two-dimensional echocardiography.
Site:
It may occur on all cardiac valves.
Clinical
presentation:
This tumour
is
an incidental finding at echocardiography, surgery or autopsy.
The tumour may also produce cerebral
embolism, or cardiac related symptoms.
Lesion in the aortic valve may cause
coronary obstruction, coronary arterial embolism and acute myocardial
infarct.
Gross features:
This
consists of filiform threads (resembling
sea anemones with multiple papillary fronds) attached to the
myocardium, being either sessile or connected by short pedicle. Their
size varies from mm to cm in diameter.
They occur mainly in the aortic valve
but may also arise from mural endocardium or any of the cardiac
valves. They may be single or multiple.
Microscopic
appearance is highly
characteristic.
i) A
central core
of dense, acellular collagen, may be surrounded by myxomatous matrix.
ii) The
peripheral rim contains coarse and fragmented elastin fibres.
iii) The
surface lining consists of a layer of endothelium, which may appear
hyperplastic.
The central core of collagen is
continuous with that of the valve leaflet.
Microscopic appearance is like that of
a normal chordae tendineae, hence the lesion should be considered as a
hamartoma. Its occurrence in older individuals speaks against a
hamartomous nature.
Histologically, it resembles Lambl’s excrescence
and is considered a similar histogenesis i.e. a proliferative response
of the endocardium related to mechanical injury and associated with
advancing age (hence the term giant Lambl’s excrescence).
Image Link & Ref(AFIP)
Possibility of fibroelastoma should be
remembered in all cases of sudden and unexpected cardiac death.
Differential
diagnosis of PFE:
Includes other
papilliferous lesions of the heart, such as myxomas, Lambl's
excrescences, bacterial vegetations, and organizing marantic (thrombotic)
endocarditis.
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.
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.
Cardiac Lipoma
;
Cardiac Angioma ;
Cardiac Fibroma
REPORTING OF CARDIAC TUMOURS |
