PPathology and Genetics of Tumours of the Lung Pleura Thymus and Heart

Pathology and Genetics of Tumours of the Lung Pleura Thymus and Heart

PPathology and Genetics of Tumours of the Lung Pleura Thymus and Heart
Pathology and Genetics of Tumours of the Lung Pleura Thymus and Heart

What is pathology?

Pathology is the study about diseases it works like as a bridge between science and medicines it is the some process about the care of patients from diagnostic testing and treatment advice to using cutting-edge genetic technologies and prevent diseases.

Researching  in pathology

                                              Pathologists play a critical role in research, advancing medicine and devising new treatments to fight viruses, infections and diseases like cancer. Doctor and Scientists  working in pathology are experts in illness and disease. They use their expertise to support every aspect of healthcare, from guiding doctors on the right way to treat common diseases, to using cutting-edge genetic technologies to treat patients with life-threatening conditions. In the last 100 years, we’ve seen significant reductions in illnesses such as polio across the world, as well as major advances in blood transfusion, vaccination and treatment of inherited conditions. This is all thanks to the pioneering work of pathologists.

Who works in pathology?

                                                There are teams of medical staff and scientists whose job it is to study samples from a person’s body to understand what’s making them unwell. These teams are made up of pathologists – who are either doctors with specialist laboratory training or scientists with specialist clinical training – as well as biomedical scientists and support staff. Doctors, nurses, surgeons and other medical staff look to pathologists and consultant clinical scientists for advice on the nature and seriousness of a patient’s illness, making sure they get the most appropriate treatment.

What is genetics?

                                    Genetics is the study of inheritance (heredity).  Heredity is a biological process where a parent passes certain genes onto their children or offspring. Every child inherits genes from both of their biological parents and these genes in turn express specific traits. Some of these traits may be physical for example hair and eye color and skin color etc. On the other hand some genes may also carry the risk of certain diseases and disorders that may pass on from parents to their offspring.

What is tumour?

                                  A tumour is also known as tumor that is a commonly used, but non-specific, term for a neoplasm. The word tumor simply refers to a mass. This is a general term that can refer to benign (generally harmless) or malignant (cancerous) growths.

Neoplasm

                 A neoplasm is an abnormal new growth of cells. The cells in a neoplasm usually grow more rapidly than normal cells and will continue to grow if not treated. As they grow, neoplasms can impinge upon and damage adjacent structures. The term neoplasm can refer to benign (usually curable) or malignant (cancerous) growths.

Genetics of  tumors

Benign tumor

            Benign tumors are non-malignant/non-cancerous tumor. A benign tumor is usually localized, and does not spread to other parts of the body. Most benign tumors respond well to treatment. However, if left untreated, some benign tumors can grow large and lead to serious disease because of their size. Benign tumors can also mimic malignant tumors, and so for this reason are sometimes treated.

Malignant tumor

                 Malignant tumors are cancerous growths. They are often resistant to treatment, may spread to other parts of the body and they sometimes recur after they were removed.

Tumors of lung pleura

What is tumor of pleura?

                                                                                   Pleural tumors are found in the pleural space—the cavity between the lungs and chest wall that contains lubricating pleural fluid. A pleural tumor is almost always metastatic (cancerous) and difficult to operate on. The prognosis is seldom encouraging. One type of tumor—called a localized fibrous tumor of the pleura (LFTP)—is the exception to the rule. Only about one in eight LFTPs is cancerous, and recovery after surgical removal is quite high despite their typically large size.

A cancerous pleural tumor is most often a secondary cancer, triggered by cancer cells that have spread to the pleural space from somewhere else in the body (usually the lungs). It is extremely unlikely that people who have never had cancer before will develop a metastatic pleural tumor. But patients who have had cancer are at risk, especially if treatment of that cancer was not totally successful in controlling it. Even so, the incidence of these tumors is rare, affecting perhaps one in 2,000 cancer patients.

The mechanism of pleura tumor

Cancer cells can be transferred to the pleural space through the bloodstream or the lymph system. They also can develop due to the pleura’s direct contact with cancer tissue pressing in from the lungs. Once there, these cells can produce one or more tumors. Metastatic pleural tumors usually cause a pleural effusion—the accumulation of an abnormal amount of pleural fluid in the chest cavity space. The fluid, which is often bloody, can provide accurate diagnostic information, so doctors commonly extract and analyze a sample of pleural fluid to help pinpoint the patient’s condition.

Symptoms of Pleural Tumors

                                                                                                         LFTPs might not have any symptoms. They’re most often found when the patient’s chest is being x-rayed for other purposes. But metastatic pleural tumors produce symptoms similar to those of lung cancer or other serious chest ailments. They include:

  • Shortness of breath when active
  • Chest pain
  • General discomfort or uneasiness
  • Cough
  • Unintended weight loss

Causes of pleura tumors

                                                                                                One of the primary underlying causes of metastatic pleural tumors has been complications from mesothelioma—that is, lung cancer related to asbestos exposure. But other cancers can metastasize to the pleural space as well. Very little is known about the cause of LFPTs, particularly the majority of these tumors that are benign. There seems to be some connection between cancerous LFPTs and either asbestos exposure or smoking.

Diagnosing Pleural Tumors

                                                                                                      There are numerous procedures at a doctor’s disposal to develop a diagnosis. They include:

  • Listening to the sound of the patient’s breathing with a stethoscope
  • Tapping on the patient’s chest and listening for a dull sound (indicating a fluid build-up)
  • Taking an x-ray to reveal the make-up and condition of the chest area
  • Performing a CT (computed tomography) scan to obtain additional “internal” details
  • Drawing fluid from the chest cavity by needle (thoracentesis) and analyzing its contents
  • Viewing the pleural space using a thoracoscope to examine its characteristics

The most preferred diagnostic test is obtaining and analyzing a sample of the fluid in the pleural cavity. That’s because it’s relatively simple for both doctor and patient, and the results are highly reliable. Occasionally, there are cases in which a surgical biopsy procedure is performed to obtain actual tissue from the tumor.

Treating Pleural Tumors

                                                                                                Many LFPTs can be surgically removed and the prognosis is generally good. Metastatic pleural tumors, however, usually cannot be surgically removed. Treatment therefore focuses on the underlying cancer, relying as appropriate on such well-known regimens as chemotherapy and radiation therapy. Any progress made with respect to the underlying cancer can extend to the pleural tumor.

The Thymus

What is thymus?

                          The thymus is a small, irregular-shaped gland in the top part of the chest, just under the breastbone and between the lungs. It is located in an area of the body called the mediastinum. The thymus is part of both the lymphatic system and the endocrine system.

What the thymus does?

                                The thymus makes T cells (T lymphocytes) that travel throughout the body to help fight infection, disease and foreign substances. The thymus also  makes hormones to help T cells develop and keep the immune system working properly. Lymphocytes travel from the bone marrow to the thymus, where they mature into T cells. Once T cells mature, they are able to leave the thymus and enter the blood so they can help the immune system. T cells also travel to lymph nodes and the spleen where they continue to mature.

Treatment of Thymus Cancers by Extent and Type of Tumor

                                                                                                               Whether or not a thymus cancer is considered resectable (able to be removed with surgery) is one of the most important factors in determining treatment options. The type of tumor is also important. Thymus carcinomas are more likely to grow and spread quickly than thymus and often require more aggressive treatment.

Resectable cancers

                                    For people with resectable cancers (almost all stage I and II thymus cancers, most stage III cancers, and small number of stage IV cancers), surgery offers the best chance for long-term survival. Surgery includes removing the entire thymus and, depending on the extent of the disease, maybe parts of nearby organs or blood vessels, too. Early stage thymomas (such as stage I and II) don’t usually need more treatment after surgery as long as the tumor was removed completely. In some cases, radiation thraphy may be considered if there is concern that any tumor was left behind. Patients with more advanced stage thymomas (such as stages III and IV) may be treated with radiation after surgery, even if all of the tumor was removed. If the tumor couldn’t be removed completely, radiation therapy is usually given after surgery. Depending on how much cancer was left behind, chemotherapy (chemo) may be added as well. Thymic carcinomas are more likely than thymomas to come back after treatment. Patients with stage I tumors may not need further treatment if the tumor was removed completely. If the tumor is more advanced, or some might have been left behind, patients are typically treated with radiation after surgery. The radiation may be given along with chemo, especially if some of the cancer is left behind after surgery.

Unresectable cancers

                                    Unresectable cancers are those that cannot be removed with surgery. This group includes cancers that are too close to vital structures (like nerves and blood vessels) or that have spread too far to be removed completely (which includes many stage III and most stage IV cancers). It also includes people who are too ill for surgery.In some cases, doctors may advise giving  chemo first to try to make the tumor resectable. If it shrinks enough, surgery is done. This is then followed by further treatment with chemo or radiation therapy.

Surgery may be the first treatment for some unresectable cancers, to try to remove as much of the tumor as possible. This is called debulking. Radiation therapy and/or chemo are then given. The hope is that the surgery may help the other treatments work better and may help people live longer, even if it doesn’t cure the cancer. Studies of this approach have had mixed results.

For patients who can’t have surgery, either because the cancer has spread too far or because they’re too sick from other serious medical conditions, chemo and radiation therapy are the main treatment options.Because unresectable cancers can be hard to treat, taking part in a clinical trial of a newer form of treatment may be a reasonable option.

Recurrent thymus cancer

                                                When cancer comes back after treatment it’s called recurrent. Recurrence can be local (in or near the same place it started) or distant (spread to organs such as the lungs, liver, or bone).Thymomas most often come back locally. Thymic carcinomas can also come back locally and in nearby lymph nodes, but they may also spread to liver, lungs, and bone. Treatment for thymus cancer that has recurred (come back) after initial treatment depends on the location of the recurrence and on what the original treatment was. If the recurrence is not too widespread, surgery may be an option and would offer the best chance for long-term survival. But in most cases, the treatment options are limited to radiation therapy and/or chemo. These treatments can often help control the cancer for a time, but they are very unlikely to result in a cure.Because recurrent cancers can be hard to treat, clinical trial of new types of treatment may be a good option.

Overview of Heart Tumors

Heart tumor

                                                A tumor is any type of abnormal growth, whether cancerous (malignant) or noncancerous (benign). Tumors in the heart may be

  • Primary (noncancerous or cancerous)
  • Metastatic (always cancerous)

Primary heart tumors 

                                                                               These are tumors that originate in the heart. Primary heart tumors are rare, occurring in fewer than 1 of 2,000 people. Most primary heart tumors are noncancerous.

Metastatic heart tumors 

                                                                             These are cancers that developed in another organ and then spread to the heart. Most heart tumors are metastatic cancer, and most are cancers that spread from the lungs. Both primary and metastatic tumors may develop in the sac that surrounds the heart (pericardium). Tumors in the pericardium may squeeze (constrict) the heart, preventing it from filling properly. Chest pain and heart failure may develop.

Noncancerous primary heart tumors

                                                                                                                                                In adults, about half of noncancerous primary heart tumors are myxomas. Myxomas usually develop in the heart’s left upper chamber (atrium). They may develop from embryonic cells located in the inner layer (lining) of the heart’s wall.

In infants and children, the most common type of noncancerous primary heart tumor is a rhabdomyoma. Rhabdomyomas, which typically occur in groups, usually grow within the heart wall and develop directly from the heart’s muscle cells. Rhabdomyomas commonly develop during infancy or childhood, often as part of a rare disease called tuberous sclerosis.

Another common noncancerous primary tumors in infants and children are fibromas. Fibromas, which typically occur as a single tumor, usually grow within the heart muscle and develop from the heart’s fibrous tissue cells.

Several other types of primary heart tumors can develop, but all are rare. Some are cancerous and some benign.

Cancerous primary heart tumors

Cancerous primary heart tumors include

  • Sarcoma
  • Mesothelioma
  • Lymphoma

Sarcomas are cancers that develop from connective tissues (blood vessels, nerves, bones, fat, muscles, and cartilage). Sarcomas develop in the right or left atrium and can block blood flow through the heart. Tumors in the right atrium can spread to the lungs.

Mesothelioma is a rare cancer that can develop in the membrane that covers the heart (pericardium), although it most often develops in the membrane that covers the lungs (pleura). Pericardial mesothelioma can spread to the spine and brain.

Lymphoma is a cancer of white blood cells known as lymphocytes. Lymphoma usually develops in the lymph nodes, spleen, and/or bone marrow. Lymphoma that develops in the heart is extremely rare. It usually occurs in people who have AIDS and grows rapidly.

Metastatic heart tumors

                                                                                                    Metastatic heart tumors originate in some other part of the body—usually the lungs, breasts, kidneys, blood, or skin—and then spread (metastasize) to the heart. They are always cancerous. Metastatic heart tumors are 30 to 40 times more common than primary heart tumors. About 10% of people who have lung or breast cancer—two of the most common cancers—and an even larger proportion of people with malignant melanoma have metastases to the heart.

Symptoms

Heart tumors may cause no symptoms, minor symptoms, or symptoms of life-threatening heart malfunction.

Noncancerous tumors can be as deadly as cancerous ones if they interfere with the function of the heart.

Major symptoms include

  • Heart failure (causing swelling of the legs, shortness of breath, and fatigue)
  • Abnormal heart rhythms (causing palpitations, weakness, or fainting)
  • Hypotension, also called low blood pressure (leading to dizziness and fainting)

Minor symptoms may include

  • Fever
  • Fatigue (lethargy)
  • Joint pain
  • Small red spots on the skin (petechiae)

Heart murmurs (sounds caused by turbulent blood flow through the heart) develop in about half of the people who have tumors that develop near or on a heart valve (such as myxomas and fibromas) because blood does not flow through the valve normally.

Heart tumors, especially myxomas and sometimes fibroelastomas, may degenerate so that pieces of them break off and travel through the bloodstream (becoming emboli). Emboli may lodge in small arteries and block blood flow. Also, blood clots that form on the surface of tumors, such as myxomas, may break off as emboli and block arteries. Symptoms due to emboli depend on where the material goes and therefore which tissues or organs are affected by the blocked artery. For example, emboli that block an artery in the brain can cause a stroke.

Diagnosis

  • Imaging with echocardiography, CT, and/or MRI

Primary heart tumors are difficult to diagnose because they are relatively uncommon and because their symptoms resemble those of many other disorders. Doctors may suspect a primary heart tumor in people who have heart murmurs, abnormal heart rhythms, unexplained symptoms of heart failure, or unexplained fever (which may be due to a myxoma). Metastatic heart tumors are suspected when people who have cancer elsewhere in the body come to a doctor with symptoms of heart malfunction. More often, heart tumors are diagnosed when a person is undergoing testing for another medical condition, such as for difficulty breathing.

If a tumor is suspected, echocardiography is usually done to confirm the diagnosis. For this procedure, a probe that emits ultrasound waves is passed over the chest, producing an image of heart structures. If another view of the heart is needed, the probe can be passed down the throat into the esophagus to record signals from just behind the heart. This procedure is called transesophageal echocardiography.

Computed tomography (CT) or magnetic resonance imaging (MRI) can provide additional information and can often distinguish noncancerous from cancerous tumors.

Unlike with tumors in most other parts of the body, doctors rarely do a heart biopsy (taking a tissue sample to look at it under a microscope). Heart biopsy may be dangerous depending upon the location of the tumor, and doctors can usually tell the difference between benign and cancerous heart tumors from the results of imaging tests.

Treatment

  • Surgical removal of noncancerous (benign) heart tumors
  • Sometimes chemotherapy or radiation for people with cancerous heart tumors

Noncancerous (benign) heart tumors

A single small noncancerous primary heart tumor can be surgically removed, usually resulting in a cure. If a large noncancerous primary tumor is significantly reducing blood flow through the heart, removal of the part of the tumor that does not grow into the heart wall may improve heart function. However, if a large part of the heart wall is involved, surgery may be impossible.

Rhabdomyomas regress without treatment in most affected newborns and usually do not require treatment.

In infants and children, a fibroma that does not affect the wall between the ventricles (septum) may be successfully removed. Tumors that affect this wall usually also affect the electrical conduction system of the heart and cannot be surgically removed. Children with this type of tumor usually die of an abnormal heart rhythm at an early age. If a fibroma is large, blocks blood flow, and has grown into the surrounding tissue, heart transplantation may be required.

Transplantation is very rarely done in either children or adults, and only noncancerous tumors are typically considered for heart transplantation.

Cancerous heart tumors

                                                                                                  Primary cancerous tumors cannot be surgically removed and are usually fatal. Chemotherapy or radiation therapy is sometimes used to slow progression of disease. Treatment of metastatic cancer depends on what organ the cancer came from and may include chemotherapy.

Pericardial tumors

                                                                        Noncancerous tumors in the pericardium can be removed surgically, but cancerous tumors are not removed because they have usually already spread elsewhere in the body. If the tumor secretes fluid that interferes with heart motion, this fluid can be drained with a small plastic tube inserted by needle into the space between the pericardium and the heart (the pericardial space). Sometimes drugs are injected into the pericardial space to slow the tumor’s growth.

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