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Cardiac sarcoma represents
the second most common primary cardiac neoplasm. Malignant
primary cardiac tumours also include primary pericardial mesotheliomas
and primary cardiac lymphomas.
Angiosarcoma :
This is probably the most common
primary malignant tumour of the heart. The tumour usually arises from
the right atrium.
Clinical
presentation:
These tumours occur in all ages and present
with a short history. Patient often presents with features of congestive cardiac failure and dyspnea.
The common
variety of tumour presents as a large obstructing mass with associated signs and
symptoms.
Less common and less symptomatic variety is the locally
infiltrative tumour.
Pericardial lesions present with signs and
symptoms of paricarditis.
Prognosis
: Patients die within 10 months of the onset of symptoms.
Rarely, patients may survive up to 3
years after treatment with surgery, chemotherapy and/or radiation.
Microscopic
features
:
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It varies from well differentiated neoplastic blood vessels to poorly
differentiated solid growth of spindle shaped and anaplastic cells
with no vasoformative pattern.
Immunohistochemistry
: The tumour shows positive
reaction to endothelial cell markers such as CD31 and CD34.
Poorly
differentiated cases are to be differentiated from other poorly
differentiated sarcomas, fibrous (sarcomatoid) mesotheliomas and
metastatic tumours.
Most of the cardiac malignant fibrous
histiocytomas are localized in the left atrium (posterior wall or
septum) and hence may be mistaken for atrial myxoma, particularly the
myxoid variant.
Myxoid variants contain foci of hypercellularity with
pleomorphism, mitotic figures, necrosis, and extensive
vascularity. All these features are usually lacking in myxoma.
Sections from several sites of the
tumour may be helpful.
Prognosis is poor even after surgical
resection (varies from 10 months to 5 years.)
Local recurrence is common and show
tendency for local invasion.
Rhabdomyosarcoma:
Cardian rhabdomyosarcomas are the
second common primary malignant cardiac tumour in adults.
A rare case of a botryoid embryonal rhabdomyosarcoma has been recorded in a boy of
8-years-old.
Clinical presentation:
Patients show a general malaise, cardiac murmurs and arrhythmias. Intramyocardial tumours may extend to involve the
visceral and parietal pericardium.
Site: In pediatric age group, tumour usually
originates from the atrial or ventricular septum, whereas in adults it
commonly arises from left atrium and right ventricle.
Gross and
microscopic features:
Morphologically the tumour is similar to that
in the soft tissues elsewhere.
Most patients die within 1 year of
diagnosis.
Fibrosarcoma
Modern techniques reported a series of
primary cardiac fibrosarcomas.
Microscopically, the tumours show a storiform
or whorled pattern of the spindle cells and the presence of giant
cells, suggestive of malignant fibrous histiocytoma.
Diagnosis of cardiac fibrosarcoma is
based on the same criteria applied to the tumours of soft tissues
elsewhere in the body.
Undifferentiated
sarcoma
These tumours arise from the atria,
ventricles and pericardium.
Immunohistochemistry reveals positive
staining for smooth muscle actin and vimentin and occasional cells show
positive staining for cytokeratin but more helpful markers are
negative.
Prognosis is poor like other sarcomas.
Other rare
primary sarcomas of the heart:
Leiomyosarcoma
The histologic diagnosis of cardiac
leiomyosarcoma is based on the same criteria as those seen in other sites.
Liposarcoma
This extremely rare tumor arises mainly
from left atrium.
Clinical manifestation depends of the
position of the tumour mass.
Metastases are common and mostly in
lungs and bones.
Histological diagnosis is based on the
same criteria as those applied to liposarcomas in other parts of the
body.
Osteosarcoma
Primary cardiac sarcomas with
osteosarcomatous differentiation is mainly seen in the left atrium.
Due to this location, they are misdiagnosed as myxoma, despite the
atypical echocardiograhic findings.
Prognosis is poor but survival time may
be prolonged by surgery.
Histologic diagnosis of cardiac
osteosarcoma is no different from that of osteosarcoma elsewhere in
the body.
Chondrosarcoma
Primary cardiac chondrosarcoma involves
the mitral valve, may be originating from left ventricle.
Histologically, main tumour mass
consists of chondrosarcoma , but other areas show the picture of
fibrosarcoma and angiosarcoma.
Clinical course from the onset of
symptoms (dyspnea) to death is about 6 months.
Synovial sarcoma
The rare biphasic malignant tumor
composed of epithelial glandular structure and a cellular spindle
shaped stroma has been recorded.Grossly it is a large tumor in the
right atrium attached by a stalk to the atriventricular ring.
Immunohistochemical markers confirm the diagnosis by excluding
mesothelioma.
Prognosis is poor and patients die
within one year.
Malignant
schwannoma
Syn: Neurogenic
sarcoma ; neurofibrosarcoma ; malignant peripheral nerve
sheath tumor.
In the heart the tumours are commonly
seen in the right ventricle.
Histological diagnosis of these tumours
in the heart is based on the same criteria as applied to neurogenic
soft tissue sarcomas elsewhere in the body.
Other primary
malignant tumours of the heart and pericardium:
Primary
cardiac lymphomas:
Mesothelioma:
Antemortem diagnosis of cardiac
mesothelioma is low due to lack of specific clinical findings.
Dyspnea and pericardial effusion are
usually the leading clinical
findings.
The tumour is more likely to be a metastatic tumour than
a primary pericardial mesothelioma.
Occassionally, differentiation from
metastatic tumor is difficult due to the diversity of cell character of
mesothelioma.
Exfoliative cytology and tissue biopsy
helps in establishing the correct diagnosis.
Microscopically, it is similar to the mesotheliomas in
other parts of the body.
Myocardial invasion of primary pericardial mesothelioma, without intracavitary extension, is common.
Massive
extension into the endocardium differentiates the primary pericardial
mesothelioma from other types of sarcoma.
Malignant teratoma
Endodermal sinus tumour has been
recorded.
The diagnosis of malignant teratoma has been made on the
basis of the findings of malignant change in one type of tissue in a
benign teratoma.
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