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

Signs and symptoms which may suggest lung cancer include:

- Respiratory symptoms: coughing, coughing up blood, wheezing, or shortness of breath

- Systemic symptoms: weight loss, weakness, fever, or clubbing of the fingernails

- Symptoms due to the cancer mass pressing on adjacent structures: chest pain, bone pain, superior vena cava obstruction, or difficulty swallowing

If the cancer grows in the airways, it may obstruct airflow, causing breathing difficulties. The obstruction can lead to accumulation of secretions behind the blockage, and predispose to pneumonia.

Depending on the type of tumor, paraneoplastic phenomena—symptoms not due to the local presence of cancer—may initially attract attention to the disease. In lung cancer, these phenomena may include hypercalcemia, syndrome of inappropriate antidiuretic hormone (SIADH, abnormally concentrated urine and diluted blood), ectopic ACTH production, or Lambert–Eaton myasthenic syndrome (muscle weakness due to autoantibodies). Tumors in the top of the lung, known as Pancoast tumors, may invade the local part of the sympathetic nervous system, leading to Horner's syndrome (dropping of the eyelid and a small pupil on that side), as well as damage to the brachial plexus.

Many of the symptoms of lung cancer (poor appetite, weight loss, fever, fatigue) are not specific. In many people, the cancer has already spread beyond the original site by the time they have symptoms and seek medical attention. Symptoms that suggest the presence of metastatic disease include weight loss, bone pain and neurological symptoms (headaches, fainting, convulsions, or limb weakness). Common sites of spread include the brain, bone, adrenal glands, opposite lung, liver, pericardium, and kidneys. About 10% of people with lung cancer do not have symptoms at diagnosis; these cancers are incidentally found on routine chest radiography.

Lung cancer, also known as lung carcinoma, is a malignant lung tumor characterized by uncontrolled cell growth in tissues of the lung. This growth can spread beyond the lung by the process of metastasis into nearby tissue or other parts of the body. Most cancers that start in the lung, known as primary lung cancers, are carcinomas. The two main types are small-cell lung carcinoma (SCLC) and non-small-cell lung carcinoma (NSCLC). The most common symptoms are coughing (including coughing up blood), weight loss, shortness of breath, and chest pains.

The vast majority (85%) of cases of lung cancer are due to long-term tobacco smoking. About 10–15% of cases occur in people who have never smoked. These cases are often caused by a combination of genetic factors and exposure to radon gas, asbestos, second-hand smoke, or other forms of air pollution. Lung cancer may be seen on chest radiographs and computed tomography (CT) scans. The diagnosis is confirmed by biopsy which is usually performed by bronchoscopy or CT-guidance.

Avoidance of risk factors, including smoking and air pollution, is the primary method of prevention. Treatment and long-term outcomes depend on the type of cancer, the stage (degree of spread), and the person's overall health. Most cases are not curable. Common treatments include surgery, chemotherapy, and radiotherapy. NSCLC is sometimes treated with surgery, whereas SCLC usually responds better to chemotherapy and radiotherapy.

Worldwide in 2012, lung cancer occurred in 1.8 million people and resulted in 1.6 million deaths. This makes it the most common cause of cancer-related death in men and second most common in women after breast cancer. The most common age at diagnosis is 70 years. Overall, 17.4% of people in the United States diagnosed with lung cancer survive five years after the diagnosis, while outcomes on average are worse in the developing world.

Many of the symptoms of NSCLC can be signs of other diseases, but having chronic or overlapping symptoms may be a signal of the presence of the disease. Some symptoms are indicators of less advanced cases while some may signal that the cancer has spread. Some of the symptoms of less advanced cancer include chronic cough, coughing up blood, chest pain, hoarseness, shortness of breath, wheezing, chest pain, weight loss, and loss of appetite. A few more symptoms associated with the early progression of the disease are feeling weak, being very tired, having trouble swallowing, swelling in the face or neck, and continuous or recurring infections like bronchitis or pneumonia. Signs of more advanced cases include bone pain, nervous system changes (headache, weakness, dizziness, balance problems, seizures), jaundice, lumps near the surface of the body, numbness of extremities due to Pancoast Syndrome, and nausea, vomiting and constipation brought on by hypercalcemia. Some more of the symptoms that indicate further progression of the cancer include shortness of breath, superior vena cava syndrome, trouble swallowing, large amounts of mucus, weakness, fatigue, and hoarseness.

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

Large cell lung carcinoma (LCLC) is a heterogeneous group of undifferentiated malignant neoplasms originating from transformed epithelial cells in the lung. LCLC's have typically comprised around 10% of all NSCLC in the past, although newer diagnostic techniques seem to be reducing the incidence of diagnosis of "classic" LCLC in favor of more poorly differentiated squamous cell carcinomas and adenocarcinomas. LCLC is, in effect, a "diagnosis of exclusion", in that the tumor cells lack light microscopic characteristics that would classify the neoplasm as a small-cell carcinoma, squamous-cell carcinoma, adenocarcinoma, or other more specific histologic type of lung cancer. LCLC is differentiated from small cell lung carcinoma (SCLC) primarily by the larger size of the anaplastic cells, a higher cytoplasmic-to-nuclear size ratio, and a lack of "salt-and-pepper" chromatin.

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.

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.

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.

Very rarely, the primary site for small-cell carcinoma is outside of the lungs and pleural space, it is referred to as extrapulmonary small-cell carcinoma (EPSCC). Outside of the respiratory tract, small-cell carcinoma can appear in the cervix, prostate, liver, pancreas, gastrointestinal tract, or bladder. It is estimated to account for 1,000 new cases a year in the U.S. Histologically similar to small-cell lung cancer, therapies for small-cell lung cancer are usually used to treat EPSCC. First line treatment is usually with cisplatin and etoposide. In Japan, the first line treatment is shifting to irinotecan and cisplatin.

When the primary site is in the skin, it is referred to as a cutaneous metastasis.

Small-cell carcinoma of the lung usually presents in the central airways and infiltrates the submucosa leading to narrowing of bronchial airways. Common symptoms include cough, dyspnea, weight loss, and debility. Over 70% of patients with small-cell carcinoma present with metastatic disease; common sites include liver, adrenals, bone, and brain.

Due to its high grade neuroendocrine nature, small-cell carcinomas can produce ectopic hormones, including adrenocorticotropic hormone (ACTH) and anti-diuretic hormone (ADH). Ectopic production of large amounts of ADH leads to syndrome of inappropriate antidiuretic hormone hypersecretion (SIADH).

Lambert-Eaton myasthenic syndrome (LEMS) is a well-known paraneoplastic condition linked to small-cell carcinoma.

Lung cancer is a large and exceptionally heterogeneous family of malignancies. Over 50 different histological variants are explicitly recognized within the 2004 revision of the World Health Organization (WHO) typing system ("WHO-2004"), currently the most widely used lung cancer classification scheme. Many of these entities are rare, recently described, and poorly understood. However, since different forms of malignant tumors generally exhibit diverse genetic, biological, and clinical properties — including response to treatment — accurate classification of lung cancer cases are critical to assuring that patients with lung cancer receive optimum management.

Approximately 99% of lung cancers are carcinoma, a term that indicates that the malignant neoplasm is composed of, or descended from, cells of epithelial lineage (i.e. derived from embryonic endoderm, as is the case in lung carcinomas, or from ectoderm), and/or that the malignant cells exhibit tissue architectural, cytological, or molecular features characteristically found in epithelial cells. Under WHO-2004, lung carcinomas are divided into 8 major taxa:

- Squamous cell carcinoma

- Small cell carcinoma

- Adenocarcinoma

- Large cell carcinoma

- Adenosquamous carcinoma

- Sarcomatoid carcinoma

- Carcinoid tumor

- Salivary gland-like carcinoma

SCLC is generally considered to be the most aggressive of these major forms of lung cancer, with the worst long term prognosis and survival rates. As a result, it is recommended that all multiphasic malignant lung tumors (i.e. those with more than one histological pattern) that are found to contain "any" proportion of SCLC cells should be classified as c-SCLC, and "not" as combined forms of any of the other histological variants present in the tumor. Currently, the only exception to this recommendation occurs in cases where anaplastic large cell lung carcinoma (LCLC) is the second histological component. In these instances, a minimum of 10% of the viable malignant cells present must be identified as LCLC before the tumor is considered to be a c-SCLC. Under the WHO-2004 classification scheme, c-SCLC is the only recognized variant of SCLC.

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.

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.

In terms of case numbers, the estimated 8,800 to 13,200 c-SCLC cases occurring annually in the U.S. makes this disease roughly comparable in incidence to Hodgkin's Disease (8,500), testicular cancer (8,400), cervical cancer (11,300), and cancers of the larynx (12,300). However, these four "better-known" cancers all have exceptionally high (85%-95%) cure rates. In contrast, less than 10% of c-SCLC patients will be cured, and thus the number of annual cases of c-SCLC is a reasonable approximation of the annual number of deaths. Therefore, given the significant incidence and mortality attributable to this malignancy, (see "Prognosis and survival") it is arguably critical to better understand these aggressive lesions so specific strategies for their management can be rationally designed.

However, as patients with tumors containing mixtures of histological subtypes are usually excluded from clinical trials, the properties of multiphasic tumors like c-SCLC are much less well understood than those of monophasic tumors. C-SCLC contains both SCLC and NSCLC by definition, and since patients with SCLC and NSCLC are usually treated differently, the lack of good data on c-SCLC means there is little evidence available with which to form consensus about whether c-SCLC should be treated like SCLC, NSCLC, or uniquely.

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.

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.

Large cell lung carcinoma with rhabdoid phenotype (LCLC-RP) is a rare histological form of lung cancer, currently classified as a variant of large cell lung carcinoma (LCLC). In order for a LCLC to be subclassified as the phenotype variant, at least 10% of the malignant tumor cells must contain distinctive structures composed of tangled intermediate filaments that displace the cell nucleus outward toward the cell membrane. The whorled eosinophilic inclusions in LCLC-RP cells give it a microscopic resemblance to malignant cells found in rhabdomyosarcoma (RMS), a rare neoplasm arising from transformed skeletal muscle. Despite their microscopic similarities, LCLC-RP is not associated with rhabdomyosarcoma.

Although rhabdoid variants of LCLC are sometimes referred to as "rhabdoid carcinomas", this particular term should be reserved for examples of "pure" rhabdoid neoplasms (i.e. those that do not contain cells containing other histological variants)

Malignant mesothelioma is an aggressive and incurable tumour caused by asbestos arising from mesothelial cells of the pleura, peritoneum (the lining of the abdominal cavity) and rarely elsewhere. Pleural mesothelioma is the most common type of mesothelioma, representing about 75 percent of cases. Peritoneal mesothelioma is the second most common type, consisting of about 10 to 20 percent of cases. Mesothelioma appears from 20 to 50 years after the initial exposure to asbestos. The symptoms include shortness of breath, chronic chest pain, cough, and weight loss. Diagnosing mesothelioma is often difficult and can include physical examination, chest X-ray and lung function tests, followed by CT scan and MRI. A biopsy is needed to confirm a diagnosis of malignant mesothelioma. Mesothelioma has a poor prognosis, with most patients dying within 1 year of diagnosis. The treatment strategies include surgery, radiotherapy, chemotherapy or multimodality treatment. Several tumour biomarkers (soluble mesothelin-related protein (SMRP), osteopontin and fibulin3) have been evaluated for diagnostic purposes to allow early detection of this disease. Novel biomarkers such as volatile organic compounds measured in exhaled breath are also promising.

Occupational cancer is cancer caused by occupational hazards. Several cancers have been directly tied to occupational hazards, including chimney sweeps' carcinoma, mesothelioma, and others.

When cancer begins, it produces no symptoms. Signs and symptoms appear as the mass grows or ulcerates. The findings that result depend on the cancer's type and location. Few symptoms are specific. Many frequently occur in individuals who have other conditions. Cancer is a "great imitator". Thus, it is common for people diagnosed with cancer to have been treated for other diseases, which were hypothesized to be causing their symptoms.

People may become anxious or depressed post-diagnosis. The risk of suicide in people with cancer is approximately double.

Local symptoms may occur due to the mass of the tumor or its ulceration. For example, mass effects from lung cancer can block the bronchus resulting in cough or pneumonia; esophageal cancer can cause narrowing of the esophagus, making it difficult or painful to swallow; and colorectal cancer may lead to narrowing or blockages in the bowel, affecting bowel habits. Masses in breasts or testicles may produce observable lumps. Ulceration can cause bleeding that, if it occurs in the lung, will lead to coughing up blood, in the bowels to anemia or rectal bleeding, in the bladder to blood in the urine and in the uterus to vaginal bleeding. Although localized pain may occur in advanced cancer, the initial swelling is usually painless. Some cancers can cause a buildup of fluid within the chest or abdomen.

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.

Esthesioneuroblastoma will first frequently present as a nasal mass. The most common signs and symptoms of esthesioneuroblastoma are nasal obstruction (70%) and epistaxis (50%). Less common symptoms include hyposmia (loss of smell), headache, rhinorrhea, vision loss, proptosis, facial pain, diplopia (double vision), masses in the neck and changes in mental status. Esthesioneuroblastoma occurs in the upper nasal cavity, near the optic nerves and optic chiasm. Thus, tumor growth can impinge nerve function and result in vision loss and diplopia. As the tumor metastasizes to the oral cavity, there can be tooth pain and tooth mobility.