Page 475 - Textbook of Pathology, 6th Edition

stroma. Occasional multinucleate tumour giant cells are 459
present.
iii) Numerous capillary-sized blood vessels are found and
the tumour cells may be aggregated around them.
iv) A few lymphocytes, plasma cells and macrophages are
seen.
v) Foci of haemorrhage and deposits of haemosiderin
granules are often present.

SECONDARY TUMOURS
Metastatic tumours of the heart are more common than the
primary tumours. About 10% cases with disseminated cancer
have metastases in the heart. Most of these result from
Figure 16.35 Appearance of the heart and the pericardium in chronic
adhesive (A) and chronic constrictive pericarditis (B). haematogenous or lymphatic spread. In descending order
of frequency, primary sites of origin are: carcinoma of the
pericardium measuring 1 to 3 cm in diameter. They are seen lung, breast, malignant lymphoma, leukaemia and malignant
most frequently on the anterior surface of the right ventricle. melanoma. Occasionally, there may be direct extension of a
The exact cause is not known but they are generally believed primary intrathoracic tumour such as carcinoma of the lung
to arise from healing of preceding pericarditis. The plaque- into the pericardium and into the cardiac chambers.
like lesions of pericardial thickenings are also termed milk
spots or soldiers’ spots as they were often found at autopsy in PATHOLOGY OF CARDIOVASCULAR
the soldiers in World War I who carried their shoulder bags INTERVENTIONS
causing pressure against the chest wall by the straps which
produced chronic irritation of the pericardium. Nowadays, with the development of surgical and non-
surgical coronary revascularisation procedures in coronary CHAPTER 16
TUMOURS OF THE HEART artery disease, it has been possible to study the pathology of
native as well as grafted vessel. However, these invasive
Tumours of the heart are classified into primary and therapeutic interventions are done in conjunction with life
secondary, the latter being more common than the former. style changes for modifying the risk factors. Besides, the
myocardial tissue by endomyocardial biopsy is also
PRIMARY TUMOURS accessible for histopathologic study.

Primary tumours of the heart are quite rare, found in 0.04% The Heart
of autopsies. In decreasing order of frequency, the benign ENDOMYOCARDIAL BIOPSY
tumours encountered in the heart are: myxoma, lipoma, Currently, it is possible to perform endomyocardial biopsy
fibroelastoma, rhabdomyoma, haemangioma and lymph- (EMB) for making a final histopathologic diagnosis in certain
angioma. The malignant tumours are still rarer, the important cardiac diseases. The main indications for EMB are:
ones are: rhabdomyosarcoma, angiosarcoma and malignant myocarditis, cardiac transplant cases, restrictive heart
mesothelioma. Out of all these, only myxoma of the heart disease, infiltrative heart diseases such as in amyloidosis,
requires elaboration. storage disorders etc.
MYXOMA. This is the most common primary tumour of the EMB is done by biopsy forceps introduced via cardiac
heart comprising about 50% of all primary cardiac tumours. catheter into either of the ventricles but preferably right
Majority of them occur in the age range of 30 to 60 years. ventricle is biopsied for its relative ease and safety. The route
Myxomas may be located in any cardiac chamber or the for the catheter may be through internal jugular vein or
valves, but 90% of them are situated in the left atrium. femoral vein for accessing the right ventricle.

Grossly, they are often single but may be multiple. They BALLOON ANGIOPLASTY
range in size from less than 1 to 10 cm, polypoid, pedun- Balloon angioplasty or percutaneous coronary intervention
culated, spherical, soft and haemorrhagic masses (PCI) is a non-surgical procedure that employs percutaneous
resembling an organising mural thrombus. Some insertion and manipulation of a balloon catheter into the
investigators actually consider them to be organising occluded coronary artery. The balloon is inflated to dilate
mural thrombi rather than true neoplasms. the stenotic artery which causes endothelial damage, plaque
Microscopically, the tumour shows the following features: fracture, medial dissection and haemorrhage in the affected
i) There is abundant myxoid or mucoid intercellular arterial wall. PCI is accompanied with insertion of coronary
stroma positive for mucin. stents in the blocked coronaries with a success rate of
ii) The cellularity is sparse. The tumour cells are generally symptoms in over 95% cases. However, case selection for
stellate-shaped, spindled and polyhedral, scattered in the
PCI is important and major indications are 2 or 3 vessel block