Symptoms or signs of mesothelioma may not appear until 20 to 50 years (or more) after exposure to asbestos. Shortness of breath, cough, and pain in the chest due to an accumulation of fluid in the pleural space (pleural effusion) are often symptoms of pleural mesothelioma.

Mesothelioma that affects the pleura can cause these signs and symptoms:

- Chest wall pain

- Pleural effusion, or fluid surrounding the lung

- Shortness of breath

- Fatigue or anemia

- Wheezing, hoarseness, or a cough

- Blood in the sputum (fluid) coughed up (hemoptysis)

In severe cases, the person may have many tumor masses. The individual may develop a pneumothorax, or collapse of the lung. The disease may metastasize, or spread to other parts of the body.

The most common symptoms of peritoneal mesothelioma are abdominal swelling and

pain due to ascites (a buildup of fluid in the abdominal cavity). Other features may include weight loss, fever, night sweats, poor appetite, vomiting, constipation, and umbilical hernia. If the cancer has spread beyond the mesothelium to other parts of the body, symptoms may include pain, trouble swallowing, or swelling of the neck or face.

These symptoms may be caused by mesothelioma or by other, less serious conditions.

Tumors that affect the abdominal cavity often do not cause symptoms until they are at a late stage. Symptoms include:

- Abdominal pain

- Ascites, or an abnormal buildup of fluid in the abdomen

- A mass in the abdomen

- Problems with bowel function

- Weight loss

Clinical factors predicting the diagnosis of malignant pleural effusions are symptoms lasting more than 1 month and the absence of fever.

Malignant pleural effusion is a condition in which cancer causes an abnormal amount of fluid to collect between the thin layers of tissue (pleura) lining the outside of the lung and the wall of the chest cavity. Lung cancer and breast cancer account for about 50-65% of malignant pleural effusions. Other common causes include pleural mesothelioma and lymphoma.

"Lung tumors" are neoplastic tumors of the lung These include:

Primary tumors of the lung/pulmonary system:

- Bronchial leiomyoma, a rare, benign tumor

- Lung cancer, the term commonly used to refer to "carcinoma of the lung"

- Pulmonary carcinoid tumor

- Pleuropulmonary blastoma

- Neuroendocrine tumors of the lung

- Lymphomas of the lung.

- Sarcomas of the lung.

- Some rare vascular tumors of the lung

Non-lung tumors which may grow into the lungs:

- Mediastinal tumors

- Pleural tumors

Metastasis or secondary tumors/neoplasms with other origin:

- Metastasis to the lung

Asbestos-related diseases are disorders of the lung and pleura caused by the inhalation of asbestos fibres. Asbestos-related diseases include non-malignant disorders such as asbestosis (pulmonary fibrosis due to asbestos), diffuse pleural thickening, pleural plaques, pleural effusion, rounded atelectasis and malignancies such as lung cancer and malignant mesothelioma.

People who worked in jobs with high asbestos dust exposure are at the highest risk of developing asbestos-related disease. However, exposure to asbestos may also occur in the worker’s home due to dust that has accumulated on the worker's clothing (para-occupational exposure). Asbestos-related diseases can also occur as a result of non-occupational, environmental exposure. Asbestos was extensively used in many building materials, therefore large quantities of asbestos still remain in buildings that were built prior to the restriction of asbestos use that applies in many countries. The weathering and aging of such buildings may cause asbestos fragments to be released in the air and create a potential hazard. Anyone who disturbs the asbestos-containing material during home maintenance and renovation can be affected, although the exact risks are difficult to quantify.

A pattern of multiple small nodular metastases has been described as miliary carcinosis which has a radiographic appearance similar to miliary tuberculosis.

The average age of onset is the early to mid 30s. Exertional dyspnea and spontaneous pneumothorax have been reported as the initial presentation of the disease in 49% and 46% of patients, respectively.

Diagnosis is typically delayed 5 to 6 years. The condition is often misdiagnosed as asthma or chronic obstructive pulmonary disease. The first pneumothorax precedes the diagnosis of LAM in 82% of patients. The consensus clinical definition of LAM includes multiple symptoms:

- Fatigue

- Cough

- Hemoptysis (rarely massive)

- Chest pain

- Chylous complications arising from lymphatic obstruction, including

- Chylothorax

- Chylous ascites

- Chylopericaridium

- Chyloptysis

- Chyluria

- Chyle in vaginal discharge

- Chyle in stool.

- Angiomyolipomas (fatty kidney tumors) are present in about 30% of patients with sporadic LAM and up to 90% of patients with TSC-LAM. Angiomyolipomas can sometimes spontaneously bleed, causing pain or hypotension.

- Cystic lymphangiomas or lymph nodes with hypodense centers, which mimic necrotizing lymphomas, ovarian or renal cancers, or other malignancies can occur in the retroperitoneum, pelvis or mediastinum.

Lung destruction in LAM is a consequence of diffuse infiltration by neoplastic smooth muscle-like cells that invade all lung structures including the lymphatics, airway walls, blood vessels and interstitial spaces. The consequences of vessel and airway obstruction include chylous fluid accumulations, hemoptysis, airflow obstruction and pneumothorax. The typical disease course displays progressive dyspnea on exertion, spaced by recurrent pneumothoraces and in some patients, chylous pleural effusions or ascites.

Most people have dyspnea on exertion with daily activities by 10 years after symptom onset. Many patients require supplemental oxygen over that interval.

Pleural carcinosis is associated with malignant pleural effusion and poor prognosis.

Symptoms of peritoneal mesothelioma include weight loss and abdominal pain and swelling due to a buildup of fluid in the abdomen. Other symptoms of peritoneal mesothelioma may include bowel obstruction, blood clotting abnormalities, anemia, and fever. If the cancer has spread beyond the mesothelium to other parts of the body, symptoms may include pain, trouble swallowing, or swelling of the neck or face.

Benign asbestos pleural effusion is an exudative pleural effusion (a buildup of fluid between the two pleural layers) following asbestos exposure. It is relatively uncommon and the earliest manifestation of disease following asbestos exposure, usually occurring within 10 years from exposure. Effusions may be asymptomatic but rarely, they can cause pain, fever, and breathlessness. Effusions usually last for 3–4 months and then resolve completely. They can also progress to diffuse pleural thickening. Diagnosis relies on a compatible history of asbestos exposure and exclusion of other probable causes.

Peritoneal mesothelioma is the name given to the cancer that attacks the lining of the abdomen. This type of cancer affects the lining that protects the contents of the abdomen and which also provides a lubricating fluid to enable the organs to move and work properly.

The peritoneum is made of two parts, the visceral and parietal peritoneum. The visceral peritoneum covers the internal organs and makes up most of the outer layer of the intestinal tract. Covering the abdominal cavity is the parietal peritoneum.

Tumor-like disorders of the lung pleura are a group of conditions that on initial radiological studies might be confused with malignant lesions. Radiologists must be aware of these conditions in order to avoid misdiagnosing patients. Examples of such lesions are: pleural plaques, thoracic splenosis, catamenial pneumothorax, pleural pseudotumor, diffuse pleural thickening, diffuse pulmonary lymphangiomatosis and Erdheim-Chester Disease.

There are few early warning signs that a patient has a DSRCT. Patients are often young and healthy as the tumors grow and spread uninhibited within the abdominal cavity. These are rare tumors and symptoms are often misdiagnosed by physicians. The abdominal masses can grow to enormous size before being noticed by the patient. The tumors can be felt as hard, round masses by palpating the abdomen.

First symptoms of the disease often include abdominal distention, abdominal mass, abdominal or back pain, gastrointestinal obstruction, lack of appetite, ascites, anemia, and/or cachexia.

Other reported symptoms include unknown lumps, thyroid conditions, hormonal conditions, blood clotting, kidney or urological problems, testicle, breast, uterine, vaginal, or ovarian masses.

Exposure to asbestos fibers reach the pleura of the lungs through the lymphatic channels or blood stream. Historically, ship builders and insulation workers are at greater risk.

Affected persons are usually asymptomatic.

On radiological studies, pleural plaques are visualized using conventional chest x-rays and computed tomography scans (CT scans). The locations of the lesions are mostly in the parietal pleura of the lungs, especially in the posterior/lateral regions of the thorax, diaphragmatic domes, and lung fissures. In some cases, calcifications are also evident, especially with CT scans.

No treatment is required since pleural plaques are benign. However, studies have demonstrated that pleural plaques are an independent risk factor for developing bronchogenic carcinoma and/or mesothelioma.

Lymphangioleiomyomatosis (LAM) is a rare, progressive and systemic disease that typically results in cystic lung destruction. It predominantly affects women, especially during childbearing years.

The differential diagnosis of LCLC-RP includes secondary metastatic lesions, melignant melanoma of the lung with rhabdoid phenotype, mucinous adenocarcinomas (particularly those featuring signet-ring cells), rhabdomyosarcoma, epitheloid angiosarcoma, pleural mesothelioma, and plasmacytoma.

The signs and symptoms of asbestosis typically manifest after a significant amount of time has passed following asbestos exposure, often several decades under current conditions in the US. The primary symptom of asbestosis is generally the slow onset of shortness of breath, especially with physical activity. Clinically advanced cases of asbestosis may lead to respiratory failure. When a physician listens with a stethoscope to the lungs of a person with asbestosis, they may hear inspiratory crackles.

The characteristic pulmonary function finding in asbestosis is a restrictive ventilatory defect. This manifests as a reduction in lung volumes, particularly the vital capacity (VC) and total lung capacity (TLC). The TLC may be reduced through alveolar wall thickening; however, this is not always the case. Large airway function, as reflected by FEV/FVC, is generally well preserved. In severe cases, the drastic reduction in lung function due to the stiffening of the lungs and reduced TLC may induce right-sided heart failure (cor pulmonale). In addition to a restrictive defect, asbestosis may produce reduction in diffusion capacity and a low amount of oxygen in the blood of the arteries.

Desmoplastic small-round-cell tumor is an aggressive and rare cancer that primarily occurs as masses in the abdomen. Other areas affected may include the lymph nodes, the lining of the abdomen, diaphragm, spleen, liver, chest wall, skull, spinal cord, large intestine, small intestine, bladder, brain, lungs, testicles, ovaries, and the pelvis. Reported sites of metastatic spread include the liver, lungs, lymph nodes, brain, skull, and bones.

The tumor is classified as a soft tissue sarcoma. It is considered a childhood cancer that predominantly strikes boys and young adults. The disease rarely occurs in females, but when it does the tumors can be mistaken for ovarian cancer.

In dogs, mast cell tumors are the most frequent round cell tumor.

Asbestosis is long term inflammation and scarring of the lungs due to asbestos. Symptoms may include shortness of breath, cough, wheezing, and chest pain. Complications may include lung cancer, mesothelioma, and pulmonary heart disease.

Asbestosis is caused by breathing in asbestos fibers. Generally it required a relatively large exposure over a long period of time. Such levels of exposure typically only occur in those who work with the material. All types of asbestos fibers are associated with concerns. It is generally recommended that currently existing asbestos be left undisturbed. Diagnosis is based upon a history of exposure together with medical imaging. It is a type of interstitial pulmonary fibrosis.

There is no specific treatment. Recommendations may include stopping smoking, influenza vaccination, pneumococcal vaccination, or oxygen therapy. Asbestosis affected about 157,000 people and resulted in 3,600 deaths in 2015. Asbestos use has been banned in a number of countries in an effort to prevent disease.

On radiological imaging, most cases of LCLC-RP are single "coin lesions" or discrete masses, but cases presenting as multiple nodules throughout the lung have also been noted. Cases with inhomogeneous-appearing consolidation on CT have been reported, as well as aerogenous, lepidic-type spread. Some large, centrally located LCLC-RP have been noted to show signs of gross necrosis and cavitation on imaging studies, as well as being associated with the presence of large bullae.

Pleural tumors may be benign (i.e. solitary fibromas) or malignant in nature. Pleural Mesothelioma is a type of malignant cancer associated with asbestos exposure.

- Mesothelial tumors: pleural malignant mesothelioma.

- Pleural sarcomas

- Pleural angiosarcoma

- Pleural desmoplastic small round cell tumor (pleural DSRCT)

- Pleural synovial sarcoma

- Pleural solitary fibrous tumor (pleural SFT)

- Smooth muscle tumors of the pleura

- Pleural carcinomas

- Pleural mucoepidermoid carcinoma

- Pleural pseudomesotheliomatous adenocarcinoma

A pleural effusion is excess fluid that accumulates in the pleural cavity, the fluid-filled space that surrounds the lungs. This excess can impair breathing by limiting the expansion of the lungs. Various kinds of pleural effusion, depending on the nature of the fluid and what caused its entry into the pleural space, are hydrothorax (serous fluid), hemothorax (blood), urinothorax (urine), chylothorax (chyle), or pyothorax (pus). A pneumothorax is the accumulation of air in the pleural space, and is commonly called a "collapsed lung."

Fibrothorax is diffuse fibrosis of the pleural space surrounding the lungs. It can have several causes including hemothorax, pleural effusion and tuberculosis. It may also be induced by exposure to certain substances, as with asbestos-induced diffuse pleural fibrosis. Idiopathic fibrothorax may also occur.

In fibrothorax, scar tissue is formed around the visceral pleura following inflammation due to pleural effusion or other pathology. The scar tissue lies in a sheet between the pleura, then fuses with the parietal pleura and the chest wall. Over time, generally the course of years, the fibrotic scar tissue slowly tightens, which results in the contraction of the entire hemithorax, and leaves the ribs immobilized. Within the chest, the lung is compressed and unable to expand, making it vulnerable to collapse. At the microscopic level, the scar tissue is composed of collagen fibers deposited in a basket weave pattern. The treatment for fibrothorax is decortication, the surgical removal of the fibrous layer of scar tissue. However, since many of the diseases and conditions resulting in fibrothorax are treatable, prevention remains the preferred method of managing fibrothorax.

Various methods can be used to classify pleural fluid.

By the origin of the fluid:

- Serous fluid (hydrothorax)

- Blood (haemothorax)

- Chyle (chylothorax)

- Pus (pyothorax or empyema)

- Urine (urinothorax)

By pathophysiology:

- Transudative pleural effusion

- Exudative pleural effusion

By the underlying cause (see next section).