Angiosarcoma is a highly invasive variety of sarcoma or cancer that may have an appearance suggestive of an infection or bruising. Read and find out all about the causes, symptoms, diagnosis and treatment of this fatal disorder.
The condition is described as a malignant neoplasm of the endothelial cells – the delicate lining of the vessel walls in the body. Neoplasm refers to an abnormal growth of tissue by rapid cellular division that forms a solid mass or lesion called tumor.
The condition is classified completely on the basis of the origin of its tumor cells. It is categorized into the following types:
Picture 1 - Angiosarcoma
This is a type of malignant tumor formed by proliferation of endothelial cells lining the blood vessels that basically encompasses the blood-filled channels and spaces. This malignant condition of the blood could be lethal, resulting in death.
It is a rare malignant tumor of the vascular endothelial cells arising from the lymphatic vessels. The lymphatic system is a wide network of organs, lymph nodes, lymph ducts and lymph vessels that aids the immune system in eliminating and destroying pathogens, toxins, and cancer cells. The lymphatic vessels form a critical component of the system as these are the reservoirs for plasma and cells that have leaked from the vascular system. These thin-walled structures also transport the lymph fluid back to the circulatory system from the tissues. Dysfunctional lymph vessels cannot effectively drain the lymph and could cause swelling of the entire lymphatic system.
As most of the organs in the body are interlaced with blood or lymph vessels, the condition can undergo metastasis (spreading of a disease from one organ or part to another non-adjacent organ or part). Therefore, the condition is sometimes called metastatic angiosarcoma. Based on the affected organ, the malignant disorder can also be classified into the following types:
This is a rare type of cancer, which originates in the endothelial cells that line the blood vessels within the breasts.
Hepatic or liver angiosarcoma
It is a fatal tumor that develops in the liver and has been ranked as the most common primary hepatic malignancy.
The condition can manifest the normal epithelium and is a rare type of soft tissue tumor.
High-grade malignant vascular tumors can grow on multiple bones, causing tenderness and swelling of the affected region.
The malignant tumor of the heart has a high rate of mortality due to its rapid relapse.
Pulmonary or lung angiosarcoma
This is normally a secondary tumor of the lung, the clinical symptoms of which are not well known.
The epithelioid cells are activated macrophages that form a crucial component of the immune system. When the malignancy reaches the deep soft tissues, these healthy cells become cancerous and impair the defense system of the body.
The prevalence of this aggressive subtype of sarcoma is low worldwide. The cutaneous form is more frequent in males than in females.
The condition can take an indefinite amount of time to develop and usually affects an array of organs in the body. The signs and symptoms however, differ according to the location of the tumor. The disorder normally shows two patterns of irregular cell growth that gives rise to either hard white nodules or blood-filled blebs. The rapid multiplication of the cells eventually spreads to the surrounding organs, causing cancer. Hemangiosarcoma generally represents the common symptoms of various blood disorders. Some of these features include:
- Coagulopathy or clotting disorder
- Cardiac arrhythmias
- Loss of appetite
- Weight loss
- Pale skin
- Bone pain
- Formation of lump or swelling under the skin
Lymphangiosarcoma typically causes a bruise mark on the anterior surface of the upper and lower limbs. Tender nodules that appear in the extremities usually develop into ulcers and ultimately lead to necrosis of the skin as well as the subcutaneous tissue.
The etiologic determinants of the malignant condition are not known. Medical researchers presume that exposure to certain toxic substances like thorium dioxide (Thorotrast), vinyl chloride and arsenic can trigger abnormal cell division. These causative agents normally belong to the class of carcinogens. Lymphangiosarcoma occurs in long-standing cases of lymphedema- swelling of the tissues in the arms and legs due to an impaired flow of the lymphatic system. The retention of fluid in the lymph vessels can evoke the vascular endothelial cells to undergo multiplication at an abnormal rate. Radiotherapy, a common technique used during breast cancer treatment, can give rise to cancerous tumors. Mastectomy or surgical removal of one or both breasts can elicit the formation of malignant tumors. AIDS-affected individuals are also at an increased risk of developing the condition, owing to a weak immune system. In a few cases, preexisting benign lesions may suddenly turn malignant.
Patients with suspected sarcoma need to undergo some medical tests in order to locate and determine the extent of tumor growth. The proper evaluation of the clinical reports forms the main tool for detection. Some of these commonly used diagnostic procedures are:
Magnetic resonance imaging (MRI)
The MRI scanner can particularly detect the exact site and size of a malignant tumor. Some contrast mediums are used to increase the accuracy of the images and pinpoint any minute changes in the structure. Injection of a tracer dye into the lymph vessels, followed by imaging of the lymphatic system, can illustrate blockages in lymph flow.
Computed tomography (CT)
This non-invasive X-ray technique is quite useful in providing detailed images of tumors affecting the organs like liver, breast, lungs and heart. CT scan helps physicians to define the lymph node architecture and identify other abnormalities.
Radiographic diagnosis of bone tumors analyzes the exact morphology of the lesion in an organized manner. However, it is one of the oldest forms of medical imaging and has very limited use.
In this nuclear medicine test, a patient is injected with a small amount of radioactive material and scanned with the aid of a gamma camera to diagnose malignancy of the bone. Tumor cells that have metastasized to the bone can also be ascertained with this method.
Tumors or other abnormal structures within the breasts can be visualized with the help of this X-ray procedure. It is currently the most efficient screening method to detect early stages of cancer.
The procedure may require removal and observation of a suspicious growth found in the body for the presence of cancer. Pathologic examination of a biopsy can determine whether a lesion is benign or malignant. Skin punch biopsy would involve removal of a piece of skin for the purpose of diagnosis of cutaneous conditions.
Angiosarcoma in dogs
Certain breeds of dogs like German Shepherds and Golden Retrievers are commonly affected with Hemangiosarcoma. The condition is generally not characterized by any clinical presentations and could be detected only when the tumor is large.
Angiosarcoma Differential Diagnosis
The disorders to be considered during the differential diagnosis of this malignant condition include:
Picture 2 - Angiosarcoma Image
- Cystosarcoma Phyllodes
- Kaposi Sarcoma
The treatment of this condition comprises of the following therapeutic options:
Affected patients have to be first evaluated in order to assess the suitability for undergoing surgical resection of a tumor. The nature and extent of cancer should be properly recognized before performing an operation as the malignant tumors have a tendency to metastasize to other areas of the body. Although individuals regain a normal life post-surgery with very few limitations, chances of recurrence are always high.
Malignant conditions are most often treated with combination of surgery and chemotherapy, in which the latter method is far more effective. The systemic treatment uses drugs that flow through the blood stream to nearly every affected part of the body. It normally destroys the malignant cells and keeps the condition from spreading.
The tumor cells usually create their own blood vessels to facilitate growth through a process called angiogenesis. Drugs like bevacizumab, itraconazole and carboxyamidotriazole obstruct this process of growth and are normally called angiogenesis inhibitors.
The clinical size and site of the tumor, severity of the cancer, and the type of treatment received are the predominant factors that affect the prognosis of this dreadful condition. The survival rate is low as most of the patients die within 15 to 24 months. However, 33% of the patients survive for as many as 5 years. The outcome is better when the condition is detected at the primary stage and treated with an aggressive use of surgical intervention with chemo-radiation.
Like most forms of cancer, Angiosarcoma is also an uncontrolled cell division, but its relation to the hematologic and lymphatic system can be debilitating to the health of the patients. If you or anyone in your family is experiencing the symptoms of this condition, do not ignore the problem and seek immediate aid from a health specialist.