Discussion
Angiosarcomas are a rare type of malignancy that involves the lining of
blood vessels and lymphatics, with a propensity to invade local and
distant organs, including the heart, lungs, lymph nodes, soft tissue,
liver, bone, and skin 1,17,18. These tumors are highly
aggressive with early metastasis and poor prognosis17–19. Due to its nonspecific symptoms and aggressive
nature, by the time of clinical presentation, the disease is usually
advanced 5,20, which poses a challenge in establishing
the diagnosis and discerning the primary origin, which might explain the
misdiagnosis of tuberculosis with our patient. Because of this
nonspecific presentation, symptoms are therefore related to the specific
organ involved, local tumor invasion, or metastasis17–19.
Symptoms and signs of angiosarcomas depend on the structure involved.
Pulmonary angiosarcoma symptoms are non-specific, ranging from cough,
hemoptysis, dyspnea, chest pain, and weight loss10,17. At the same time, cardiac involvement presents
mainly with arrhythmias, features of heart failure, pericardial
effusion, hypotension, and syncope depending on the structure involved10,21. Our patient presented with a myriad of these
symptoms.
The imaging modality is dictated by the extent and specific organs that
are involved. Pulmonary angiosarcomas features are variable and
atypical. Shimabukuro et al. reported 31 cases of CT features of primary
pulmonary angiosarcomas and reported the most frequent finding to be the
pulmonary nodules (87%), as was the case in our patient. Other features
were infiltrations, ground glass appearance, pleural effusions, and
invasion of other organs 22.
In cardiac angiosarcomas, echocardiography and MRI scan form a major
component in the workup with echocardiography reported to have 97%
sensitivity in detecting cardiac tumors. Other advantages of
echocardiography include - it is inexpensive, noninvasive, widely
available, and can reveal tumor location, extent, and cardiac function.
Its limitations are the inability to characterize different tissue types
and their reliance on the operator experience. However, CT and MRI are
superior to cardiac ultrasound, with CT scan being able to provide
information on the vascular anatomy of the mass. On the other hand, MRI
has better tissue characterization and lack of ionizing radiation23.
Like in our patient, when the heart is involved, it extensively
infiltrates cardiac structures and may extend through the heart wall to
involve adjacent structures 10,23.
Transthoracic echocardiography (TTE) aids in detecting the tumors and
its size, identify the site of attachment, and the pattern of tumor
movement 22,23, as was noted in our patient. It is
inexpensive, noninvasive, and widely available even in the
resource-limited centers. TEE has a much higher resolution for
differentiating between benign and malignant tumors23.
Chest X-ray is not diagnostic of cardiac angiosarcomas but can unmask
cardiomegaly, which is the most common finding, widened mediastinum,
hilar adenopathy, focal cardiac mass, pulmonary consolidation, or
pericardial effusion 12,23. On the other hand, similar
to our patient, the CT scan findings may reveal multifocal or solitary
lesions demonstrating a predominant, highly vascular right atrial mass
that involves the cardiac chambers which may be nodular and irregular23–25; and PET can help in the diagnosis, staging,
and follow-up 26,27.
Like in most mesenchymal tumors, biochemical parameters do not help much
in the diagnostic workup; however, histopathology and immunochemistry
may still confirm the diagnosis. Immunoexpression of vascular markers,
such as ERG, CD31, CD34, and FLI1, that we could not test may also aid
in achieving the correct diagnosis 28.
A multidisciplinary approach is advisable with surgical resection in
localized disease, which cannot be achieved in most cases due to the
vascular nature of the disease. With a 5-year survival rate of less than
50%, treatment options are limited and carry a poor prognosis. Some
authors advocate an aggressive treatment approach involving both
surgical resection and radiotherapy 29. While several
agents such as adriamycin, ifosfamide, cyclophosphamide, vincristine,
dacarbazine, and paclitaxel are used in the management of these
patients, there is still some debate on the role of adjuvant
chemotherapy and the choice of agents 30,31.