What is The Most Common Type of Mesothelioma?

Pleural Mesothelioma: The Most Common Form

Pleural mesothelioma is the most prevalent type of mesothelioma, accounting for about 75% of all cases. It originates in the pleura, the thin membrane that lines the chest cavity and surrounds the lungs. This location plays a significant role in how the disease presents itself, spreads, and is treated.

Key Characteristics of Pleural Mesothelioma

• Location: Affects the pleura, which covers the lungs and lines the chest wall.
• Symptoms: Includes chest pain, persistent cough, shortness of breath, and pleural effusion (buildup of fluid between the lung and chest wall).
• Diagnosis: Often diagnosed through imaging tests like chest X-rays, CT scans, and confirmed with a biopsy.
• Treatment: Common treatments include surgery (such as pleurectomy/decortication or extrapleural pneumonectomy), chemotherapy, and radiation therapy.

Comparison with Other Types of Mesothelioma

Peritoneal Mesothelioma

• Location: Affects the peritoneum, the lining of the abdominal cavity.
• Prevalence: Accounts for about 20-25% of mesothelioma cases, making it the second most common form.
• Symptoms: Abdominal pain, swelling, changes in bowel habits, and unexplained weight loss.
• Treatment: Often treated with cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (HIPEC), a procedure where heated chemotherapy is applied directly to the abdominal cavity.

Pericardial Mesothelioma

• Location: Affects the pericardium, the lining around the heart.
• Prevalence: Extremely rare, accounting for about 1-2% of cases.
• Symptoms: Chest pain, heart palpitations, difficulty breathing, and pericardial effusion (fluid buildup around the heart).
• Treatment: Treatment is challenging due to the tumor’s proximity to the heart. Options may include surgery, chemotherapy, and palliative care to manage symptoms.

Testicular Mesothelioma

• Location: Affects the tunica vaginalis, the lining around the testicles.
• Prevalence: The rarest form, representing less than 1% of all mesothelioma cases.
• Symptoms: Testicular lumps or swelling, often discovered during surgery for other conditions.
• Treatment: Typically involves surgery to remove the affected testicle (orchiectomy), sometimes followed by chemotherapy or radiation therapy.

Unique Aspects of Pleural Mesothelioma

Spread and Prognosis

• Aggressiveness: Pleural mesothelioma is known for its aggressive nature and tendency to spread rapidly within the chest cavity, often involving the diaphragm, heart, and even the other lung.
• Prognosis: The prognosis for pleural mesothelioma is generally poor, with a median survival time of about 12-21 months after diagnosis. However, outcomes can vary based on the stage at diagnosis, the patient’s overall health, and the effectiveness of treatment.

Impact on Breathing

• Because pleural mesothelioma directly affects the lungs, it often leads to severe respiratory symptoms that can significantly impact a patient’s quality of life. The buildup of fluid in the pleural space (pleural effusion) can cause the lungs to partially collapse, leading to difficulty breathing and chest pain.

Treatment Challenges

• Complex Surgery: Surgical options like extrapleural pneumonectomy (EPP), which involves removing the affected lung along with parts of the diaphragm and surrounding tissues, are complex and carry significant risks.
• Treatment Response: Pleural mesothelioma often responds poorly to standard chemotherapy, necessitating the exploration of multimodal approaches, including surgery, radiation, and emerging therapies like immunotherapy.

Conclusion

Pleural mesothelioma stands out as the most common and most researched type of mesothelioma, primarily due to its high incidence and the severity of symptoms it causes. While it shares similarities with other forms of mesothelioma, particularly in its link to asbestos exposure, its location in the pleura brings unique challenges in terms of diagnosis, treatment, and prognosis. Understanding these differences is essential for anyone facing this disease, whether patient, caregiver, or healthcare provider.

Sources:

• National Cancer Institute - Malignant Mesothelioma Treatment (PDQ®)
• Centers for Disease Control and Prevention (CDC) - Asbestos and Your Health
• American Cancer Society - What Is Mesothelioma?