Mesothelioma is an aggressive and rare form of cancer accounting for 0.3% of all cancer diagnoses in the US. It has a low survival rate and an average life expectancy of 1-2 years. However, an experienced physician can improve prognosis with a customized treatment plan.
Asbestos is considered a primary cause of mesothelioma. This cancer develops after exposure to a deadly dose of asbestos fibers. These fibers, when inhaled, get lodged in the outer lining (mesothelium) of internal organs, damaging the tissue lining. This damage can cause healthy cells to mutate and become cancerous. Cancerous cells grow and multiply rapidly.
The symptoms of mesothelioma include chest pain, shortness of breath, fatigue, fever, and night sweats. These symptoms may appear decades after initial asbestos exposure as mesothelioma cell types can stay dormant for years.
The people most at risk of developing this condition can be construction and industrial workers, US army veterans, and their family members, given the extensive use of asbestos in these professions.
Different mesothelioma support centers exist around the country to help you navigate the legal and medical world after diagnosis. Several treatment options are available that can alleviate symptoms and prolong life. However, the treatment plan depends on the type of mesothelioma.
Let’s discuss those types.
Types of Mesothelioma
Mesothelioma is categorized into four types based on the affected organ. It commonly develops in the linings of the lungs and abdomen. Rarely, it can also develop in heart and testes linings. The types of mesothelioma are as follows;
1. Pleural Mesothelioma
Pleural mesothelioma develops in the lung lining. It is the most common form of mesothelioma. According to the American Cancer Society, almost 80-90% of mesothelioma diagnoses are pleural. It affects the protective lining covering the lungs and chest cavity. It thickens the lining resulting in abnormal expansion of the chest and lungs. It may also lead to fluid buildup in the chest cavity. An X-ray can help confirm fluid buildup. Diagnosis is often delayed as this disease has symptoms similar to other common illnesses.
Surgery is considered an effective treatment option for the early stages. Additionally, chemotherapy and radiotherapy may be recommended. Based on the health condition and age of the patient, immunotherapy may also be effective.
2. Peritoneal Mesothelioma
Peritoneal mesothelioma develops in the lining of the abdomen. It is the second most common type of mesothelioma and accounts for 10% of mesothelioma diagnoses. This cancer type develops in the peritoneum, a membrane that covers the abdominal organs and cavity. It is caused by either ingestion of asbestos fibers or inhaling fibers that then reach the abdomen through the lymphatic system. Its symptoms may include nausea, vomiting, abdominal pain, and swelling. The condition can lead to a fluid buildup in the abdominal cavity.
This type of mesothelioma has the highest survival rate. A promising treatment option includes surgery combined with hyperthermic intraperitoneal chemotherapy (HIPEC).
3. Pericardial Mesothelioma
Pericardial mesothelioma develops in the lining of the heart. It is a rare type of this disease and accounts for only 1% of all mesothelioma diagnoses. This cancer affects the heart sac called the pericardium. Due to the proximity of the tumor to the heart, even initial symptoms can be quite severe. Its symptoms may include irregular heartbeat, chest pain, difficulty breathing, cough, and fluid buildup in the pericardium.
It has a low life expectancy, and palliative treatment is recommended to alleviate symptoms. However, cases have been reported of people surviving beyond the expected survival time after the initial diagnosis of this disease.
4. Testicular Mesothelioma
Testicular mesothelioma develops in the lining of the testes. It is the rarest type of mesothelioma, with only about 100 cases ever reported. Hence, it accounts for less than 1% of all mesothelioma cases ever diagnosed. It develops in the lining of the testicles called tunica vaginalis. Its symptoms may include scrotal swelling and painless lumps in the testicles.
It has a high survival rate. However, the recurrence rate of testicular mesothelioma is also high. Treatment options include surgery and chemotherapy.
Mesothelioma Cell Types
Malignant mesothelioma has various cell types. Doctors consider the cell type before designing a treatment plan as each cell type responds differently to a specific treatment. All cell types also express themselves differently in a patient.
The three primary cell types are as follows;
Epithelioid Cell
Epithelioid cells are the most common mesothelioma cell type accounting for 70-80% of all mesothelioma cases. These cells are named after the thin sheet-like epithelial cells and don’t spread rapidly as they’re less aggressive. These cells respond well to the treatment and have a favorable prognosis. About 50% of pleural mesothelioma and 75% of peritoneal mesothelioma are epithelioid.
Sarcomatoid Cell
Sarcomatoid cells are the least common mesothelioma cell type accounting for 10-20% of all mesothelioma diagnoses. This cell type is aggressive, growing and spreading quickly, making it challenging to treat with an unfavorable prognosis. About 20% of pleural and 1% of peritoneal tumors are sarcomatoid. Mesothelioma with sarcomatoid cell type is referred to as either sarcomatous or spindle malignant fibrous mesothelioma.
Biphasic Cell
Biphasic cell types are a mix of both epithelial and sarcomatoid cell types. They account for 30-40% of all mesothelioma diagnoses. The ratio of epithelial and sarcomatoid cells determines the aggressiveness of mesothelioma. The life expectancy and treatment options for biphasic cells are also determined by which cell type (epithelial or sarcomatoid) is higher in number. More epithelial cells will lead to a better prognosis and vice versa. Around 30% of pleural and 25% of peritoneal mesothelioma are biphasic.
Rare mesothelioma cell types are the subtypes of the primary three cell types. These cell types are difficult to diagnose. Some of these rare cell types are benign. Cancerous rare cell types may have a poor prognosis.
These rare subtypes can include;
- Cystic mesothelioma
- Small cell mesothelioma
- Desmoplastic mesothelioma
- Adenomatoid mesothelioma
The Wrap Up
It is essential to identify the type of mesothelioma before beginning treatment. Different types of this disease respond differently to various treatments. Each mesothelioma type has a different prognosis and level of severity. Therefore, diagnosis of the mesothelioma type will help devise the best possible treatment plan. Mesothelioma cancer cells can also be categorized into several cell types. The identification of both the type of mesothelioma and its cell type is critical to designing an appropriate treatment plan.