Mesothelioma Diagnosis

After analyzing the patient's symptoms and medical history, doctors use tests such as physical exams, imaging tests, and biopsies to diagnose mesothelioma. Due to the aggressive nature of mesothelioma, early detection and avoidance of misdiagnosis are essential to ensure the most favorable prognosis for the patient.

How is mesothelioma diagnosed?

When a patient has symptoms of mesothelioma, the doctor conducts a physical examination, examines the patient's medical history, and begins to rule out more common diseases and conditions. Doctors will then ask for a series of tests and procedures to identify the cause of the symptoms.

Mesothelioma Imaging Scanners

Imaging tests help identify tumors, tumor localization, and cancer metastasis during the diagnostic process. The most common scanners used to diagnose mesothelioma include X-rays, MRI scans, CT scans, PET scans and ultrasound.

X-rays: X-rays provide 2D images of bones and soft tissue to identify abnormalities and help eliminate other conditions. Chest or abdominal radiographs are the most common for mesothelioma and may reveal mesothelioma manifestations with common manifestations such as pleural effusions or abdominal ascites (fluid accumulation around the lungs or abdomen).

CT Scans: CT (Computed Tomography) scans provide 3D images of the body, distinguishing abnormalities from normal organs and tissues. These are used as an important tool in the diagnosis of all types of mesothelioma and in post-treatment follow-up.

MRI Scanners: Magnetic resonance imaging (MRI) scanners provide detailed 3D images of bones and soft tissue, providing clarity between normal and potentially cancerous tissue. MRI imaging may be useful for detecting mesothelioma invasion into surrounding tissue as part of staging and pre-surgical assessment.

PET scans: PET scans use nuclear imaging technology to identify the high metabolic activity of cancer cells and distinguish between normal and cancerous tissue. These scans are useful for showing metastases to nearby lymph nodes or to distant areas of the body.

Ultrasound: Ultrasound provides live images of the body, showing organs, vessels and tissues, and helps identify tumors after the onset of symptoms. In mesothelioma, this type of imaging can be used to identify pleural / ascites effusion pockets that may need to be drained.

Blood tests and biomarkers for mesothelioma

Blood tests can be used to search for mesothelioma biomarkers or substances in the blood that may suggest the presence of malignant mesothelioma. For example, healthy mesothelial cells produce normal levels of mesothelin, but malignant mesothelial cells produce higher levels of protein, which can be detected in blood tests, making diagnosis easier.

Various blood tests can be used to identify particular by-products common to mesothelioma patients, as well as many biomarkers that continue to emerge. Biomarkers may suggest the presence of mesothelioma, which may then lead to further assessment and earlier diagnosis. Biomarkers can also be used to monitor the effectiveness of treatments. At present, no blood test can definitively diagnose mesothelioma. 

Mesothelioma blood tests and biomarkers that have demonstrated their utility include:

⦁ MESOMARK

⦁ MPF 

⦁ CA-125 

⦁ N-ERC/Mesothelin Test 

⦁ Osteopontin 

⦁ Fibulin-3 

⦁ Il-6

Mesothelioma biopsies

Biopsies are the most important step in the diagnosis of mesothelioma and the only way to confirm cancer. Mesothelioma biopsies take a liquid or cancerous tissue for analysis, which will then be used to confirm the type of mesothelioma diagnosed and histologically, as well as to determine treatment options. There are four types of common biopsies for mesothelioma, including fluid drainage, needle biopsies, camera-assisted biopsies, and surgical biopsies.

Fluid Drainage: The drainage of pleural / pericardial effusions or abdominal ascites using a needle or catheter is the least invasive, using a needle or catheter to extract a sample of fluid from the affected area. Types of fluid drainage procedures include thoracentesis, paracentesis and pericardiocentesis. However, although the results may be suggestive, in most cases a fluid sample can not confirm the diagnosis of mesothelioma.

Needle Biopsies: One of the least invasive biopsies, it involves using a needle to extract a tissue sample from an affected area, such as the pleura or lymph node involved.

Camera-assisted surgical biopsies: Camera-assisted biopsies are minimally invasive. They consist of using a small tube with a camera to locate and visually recover a sample of tissue to be analyzed. The types of camera-assisted biopsies used for mesothelioma include thoracoscopy, laparoscopy, and mediastinoscopy.

Open surgical biopsies: Surgical biopsies are the most invasive. They are often used when tumors are difficult to reach with needle or camera-assisted biopsies. The types of surgical biopsies used for mesothelioma include thoracotomy and laparotomy.

Mesothelioma Pathology 

The mesothelioma Pathology describes the microscopic appearance of mesothelioma in a tissue sample or fluid. Histology and cytology are two types of pathology samples created from a biopsy procedure, which are then evaluated under a microscope by a pathologist to confirm a diagnosis of mesothelioma, providing information that will guide staging and diagnosis. , while helping to prevent misdiagnosis.

Histology: Histology focuses on tissue samples, examines cell anatomy and surrounding findings to determine malignancy, type of mesothelioma cancer, and whether the cell type is epithelial, sarcomatoid, or biphasic. Pathologists almost always need histological biopsy samples to confirm the diagnosis of mesothelioma.

Cytology: Cytology focuses on tissue or fluid samples to examine the appearance of individual cells and groups of cells to better characterize and diagnose them. Pathologists are generally not able to confirm the diagnosis of mesothelioma from a cytological sample.

Common Mesothelioma Misdiagnosis 

Mesothelioma is a rare cancer often confused with more common diseases and conditions. Every step of the diagnostic process, especially a biopsy, is crucial to avoid any misdiagnosis. If mesothelioma is confused with another problem, treatment will be delayed, which may worsen the patient's prognosis. Diagnostic errors vary by type, as shown below.

Pleural mesothelioma: Pneumonia, emphysema, asthma, bronchial infections, chronic obstructive pulmonary disease (COPD), adenocarcinoma and other lung cancers.

Peritoneal mesothelioma: benign cystic mesothelioma, irritable bowel syndrome (IBS), Crohn's disease, hernia, ovarian cancer and other cancers of the abdomen.

Pericardial mesothelioma: coronary artery disease, heart failure, tuberculous pericarditis, synovial sarcoma and other heart-related cancers.

Testicular mesothelioma: epididymitis, testicular cancer, inguinal hernia, adenocarcinoma and other testicular cancers.

Importance of early detection of mesothelioma

Malignant Mesothelioma is an aggressive cancer that spreads quickly. Although there is no cure for this cancer, treatment of mesothelioma can prolong the life expectancy of patients, especially if the disease is detected early.

Patients diagnosed at stages 1 or 2 are generally able to undergo aggressive surgeries and multimodal therapy, which has resulted in longer survival. People diagnosed at stage 3 or 4 have more limited treatment options and a poorer prognosis.

Mesothelioma has a long latency period, and the onset of symptoms can take decades, making early diagnosis difficult. Misdiagnosis is also common because of scarcity and nonspecific symptoms. However, knowledge of a history of asbestos exposure, coupled with improved diagnostic tools, suggests that cancer can be detected early, providing patients with the best possible prognosis.