Mediastinal tumors

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Mediastinal tumor
Primitive neuroepithelium intermed mag.jpg
Micrograph of the primitive neuroepithelium of an immature teratoma of the mediastinum. H&E stain.
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A mediastinal tumor is a tumor in the mediastinum, the cavity that separates the lungs from the rest of the chest. It contains the heart, esophagus, trachea, thymus, and aorta. The most common mediastinal masses are thymoma (20% of mediastinal tumors), usually found in the anterior mediastinum, followed by neurogenic Timor (15–20%) located in the anterior mediastinum. [1] Lung cancer typically spreads to the lymph nodes in the mediastinum.

Contents

The mediastinum has three main parts: the anterior mediastinum (front), the middle mediastinum, and the posterior mediastinum (back). Masses in the anterior portion of the mediastinum can include thymoma, lymphoma, pheochromocytoma, germ cell tumors including teratoma, thyroid tissue, and parathyroid lesions. Masses in this area are more likely to be malignant than those in other compartments. [2] [3]

Masses in the posterior portion of the mediastinum tend to be neurogenic in origin, and in adults tend to be of neural sheath origin including neurilemomas and neurofibromas. [1]

Types

Thymoma

Most common primary anterior mediastinal tumor (20%) in adults but rarely seen in children. It can be classified as lymphocytic, epithelial, or spindle cell histologies, but the clinical significance of these classifications is controversial. [4] Tonofibrils seen under electron microscopy can differentiate thymoma from other tumors such as carcinoid, Hodgkin's, and seminoma. Patients are usually asymptomatic but can present with myasthenia gravis-related symptoms, substernal pain, dyspnea, or cough. Invasive tumors can produce compression effects such as superior vena cava syndrome. Thymomas are diagnosed with CT or MRI revealing a mass in anterior mediastinum. Therapy in stage I tumors consists of surgical resection with good prognosis. Stage II–III requires maximal resection possible followed by radiation. Stage IV disease requires addition of cisplatin-based chemotherapy in addition to those in stage II and III. For those with invasive thymoma, treatment is based on induction chemotherapy, surgical resection, and post-surgical radiation. 5-year survival for invasive thymoma is between 12 and 54% regardless of any myasthenia gravis symptoms.[ citation needed ]

Lymphoma

Micrograph of a primary mediastinal large B-cell lymphoma, a rare type of lymphoma that arises in the mediastinum. H&E stain. Primary mediastinal large B-cell lymphoma - very high mag.jpg
Micrograph of a primary mediastinal large B-cell lymphoma, a rare type of lymphoma that arises in the mediastinum. H&E stain.

Second most common primary anterior mediastinal mass in adults. Most are seen in the anterior compartment and rest are seen in middle compartment. Hodgkin's lymphoma usually present in 40–50's with nodular sclerosing type (7), and non-Hodgkin's appears in all age groups. There is also primary mediastinal B-cell lymphoma with exceptionally good prognosis. [5] [6] [7]

Common symptoms of a mediastinal lymphoma of include fever, weight loss, night sweats, and compressive symptoms such as pain, dyspnea, wheezing, Superior vena cava syndrome, pleural effusions. Diagnosis usually by CT showing lobulated mass. Confirmation done by tissue biopsy of accompanying nodes if any, mediastinoscopy, mediastinotomy, or thoracotomy. FNA biopsy is usually not adequate. Treatment of mediastinal Hodgkin's involves chemotherapy and/or radiation. 5 year survival is now around 75%. Large-cell type may have somewhat better prognosis. Surgery is generally not performed because of invasive nature of tumor.[ citation needed ]

Of all cancers involving the same class of blood cell, 2% of cases are mediastinal large B cell lymphomas. [8]

Diagnosis

In several editions of Physical Diagnosis, [9] concerning mediastinal tumors the author writes:

According to Christian1 the mediastinal neoplasms which are neither so rare nor so obscure as to make diagnosis practically impossible are: (1) Sarcoma (including lymphosarcoma, leucaemic growths, and Hodgkins' disease; (2) Teratoma and cyst.

Many signs and symptoms of a mediastinal tumor do not distinguish between these two principal classes of mediastinal tumor. However, on a radiograph usually the former class will have an irregular shape and the latter class will have a smooth spherical or ovoid shape. A large minority of patients with a mediastinal teratoma (including dermoid cyst) will cough up hair. [9] For a differential diagnosis, the key is to exclude aneurysm.[ citation needed ]

See also

Related Research Articles

<span class="mw-page-title-main">Brain tumor</span> Neoplasm in the brain

A brain tumor occurs when abnormal cells form within the brain. There are two main types of tumors: malignant (cancerous) tumors and benign (non-cancerous) tumors. These can be further classified as primary tumors, which start within the brain, and secondary tumors, which most commonly have spread from tumors located outside the brain, known as brain metastasis tumors. All types of brain tumors may produce symptoms that vary depending on the size of the tumor and the part of the brain that is involved. Where symptoms exist, they may include headaches, seizures, problems with vision, vomiting and mental changes. Other symptoms may include difficulty walking, speaking, with sensations, or unconsciousness.

<span class="mw-page-title-main">Thymus</span> Endocrine gland

The thymus is a specialized primary lymphoid organ of the immune system. Within the thymus, thymus cell lymphocytes or T cells mature. T cells are critical to the adaptive immune system, where the body adapts to specific foreign invaders. The thymus is located in the upper front part of the chest, in the anterior superior mediastinum, behind the sternum, and in front of the heart. It is made up of two lobes, each consisting of a central medulla and an outer cortex, surrounded by a capsule.

<span class="mw-page-title-main">Lymphoma</span> Hematologic cancer that affects lymphocytes

Lymphoma is a group of blood and lymph tumors that develop from lymphocytes. The name typically refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enlarged lymph nodes, fever, drenching sweats, unintended weight loss, itching, and constantly feeling tired. The enlarged lymph nodes are usually painless. The sweats are most common at night.

<span class="mw-page-title-main">Teratoma</span> Type of germ cell tumor

A teratoma is a tumor made up of several different types of tissue, such as hair, muscle, teeth, or bone. Teratomata typically form in the tailbone, ovary, or testicle.

<span class="mw-page-title-main">Ovarian cancer</span> Cancer originating in or on the ovary

Ovarian cancer is a cancerous tumor of an ovary. It may originate from the ovary itself or more commonly from communicating nearby structures such as fallopian tubes or the inner lining of the abdomen. The ovary is made up of three different cell types including epithelial cells, germ cells, and stromal cells. When these cells become abnormal, they have the ability to divide and form tumors. These cells can also invade or spread to other parts of the body. When this process begins, there may be no or only vague symptoms. Symptoms become more noticeable as the cancer progresses. These symptoms may include bloating, vaginal bleeding, pelvic pain, abdominal swelling, constipation, and loss of appetite, among others. Common areas to which the cancer may spread include the lining of the abdomen, lymph nodes, lungs, and liver.

<span class="mw-page-title-main">Thymoma</span> Medical condition

A thymoma is a tumor originating from the epithelial cells of the thymus that is considered a rare malignancy. Thymomas are frequently associated with neuromuscular disorders such as myasthenia gravis; thymoma is found in 20% of patients with myasthenia gravis. Once diagnosed, thymomas may be removed surgically. In the rare case of a malignant tumor, chemotherapy may be used.

<span class="mw-page-title-main">Germ cell tumor</span> Medical condition

Germ cell tumor (GCT) is a neoplasm derived from the primordial germ cells. Germ-cell tumors can be cancerous or benign. Germ cells normally occur inside the gonads. GCTs that originate outside the gonads may be birth defects resulting from errors during development of the embryo.

<span class="mw-page-title-main">Mediastinum</span> Central part of the thoracic cavity

The mediastinum is the central compartment of the thoracic cavity. Surrounded by loose connective tissue, it is an undelineated region that contains a group of structures within the thorax, namely the heart and its vessels, the esophagus, the trachea, the phrenic and cardiac nerves, the thoracic duct, the thymus and the lymph nodes of the central chest.

The International Classification of Diseases for Oncology (ICD-O) is a domain-specific extension of the International Statistical Classification of Diseases and Related Health Problems for tumor diseases. This classification is widely used by cancer registries.

<span class="mw-page-title-main">Lymphoma in animals</span> Type of cancer in animals

Lymphoma (lymphosarcoma) in animals is a type of cancer defined by a proliferation of malignant lymphocytes within solid organs such as the lymph nodes, bone marrow, liver and spleen. The disease also may occur in the eye, skin, and gastrointestinal tract.

Sacrococcygeal teratoma (SCT) is a type of tumor known as a teratoma that develops at the base of the coccyx (tailbone) and is thought to be primarily derived from remnants of the primitive streak. Sacrococcygeal teratomas are benign 75% of the time, malignant 12% of the time, and the remainder are considered "immature teratomas" that share benign and malignant features. Benign sacrococcygeal teratomas are more likely to develop in younger children who are less than 5 months old, and older children are more likely to develop malignant sacrococcygeal teratomas.

<span class="mw-page-title-main">Gastric lymphoma</span> Medical condition

Primary gastric lymphoma is an uncommon condition, accounting for less than 15% of gastric malignancies and about 2% of all lymphomas. However, the stomach is a very common extranodal site for lymphomas. It is also the most common source of lymphomas in the gastrointestinal tract.

Mediastinal germ cell tumors are tumors that derive from germ cell rest remnants in the mediastinum. Germ cell tumors most commonly occur in the gonad but occasionally elsewhere.

<span class="mw-page-title-main">Thymic carcinoma</span> Medical condition

Thymic carcinoma, or type C thymoma, is a malignancy of the thymus. It is a rare cancer that is often diagnosed at advanced stages. Recurrence following treatment is common, and thymic carcinoma is associated with a poor prognosis.

<span class="mw-page-title-main">Immature teratoma</span> Medical condition

An immature teratoma is a teratoma that contains anaplastic immature elements, and is often synonymous with malignant teratoma. A teratoma is a tumor of germ cell origin, containing tissues from more than one germ cell line, It can be ovarian or testicular in its origin. and are almost always benign. An immature teratoma is thus a very rare tumor, representing 1% of all teratomas, 1% of all ovarian cancers, and 35.6% of malignant ovarian germ cell tumors. It displays a specific age of incidence, occurring most frequently in the first two decades of life and almost never after menopause. Unlike a mature cystic teratoma, an immature teratoma contains immature or embryonic structures. It can coexist with mature cystic teratomas and can constitute of a combination of both adult and embryonic tissue. The most common symptoms noted are abdominal distension and masses. Prognosis and treatment options vary and largely depend on grade, stage and karyotype of the tumor itself.

<span class="mw-page-title-main">Primary mediastinal B-cell lymphoma</span> Medical condition

Primary mediastinal B-cell lymphoma, abbreviated PMBL, is a rare type of lymphoma that forms in the mediastinum and predominantly affects young adults.

<span class="mw-page-title-main">Scrotal ultrasound</span> Medical ultrasound examination of the scrotum.

Scrotalultrasound is a medical ultrasound examination of the scrotum. It is used in the evaluation of testicular pain, and can help identify solid masses.

Primary mediastinal (thymic) large B-cell lymphoma is a distinct type of diffuse large B-cell lymphoma involving the mediastinum, recognized in the WHO 2008 classification.

<span class="mw-page-title-main">Mediastinal shift</span> Medical condition

Mediastinal shift is an abnormal movement of the mediastinal structures toward one side of the chest cavity. A shift indicates a severe imbalance of pressures inside the chest. Mediastinal shifts are generally caused by increased lung volume, decreased lung volume, or abnormalities in the pleural space. Additionally, masses inside the mediastinum or musculoskeletal abnormalities can also lead to abnormal mediastinal arrangement. Typically, these shifts are observed on x-ray but also on computed tomography (CT) or magnetic resonance imaging (MRI). On chest x-ray, tracheal deviation, or movement of the trachea away from its midline position can be used as a sign of a shift. Other structures, like the heart, can also be used as reference points. Below are examples of pathologies that can cause a mediastinal shift and their appearance.

A cervical thymic cyst, also called thymopharyngeal duct cyst, is a fluid-filled mass that occurs when the thymopharyngeal duct, an embryonic structure connecting the nascent thymus with the embryonic pharynx, fails to close and disappear. A thymic cyst is typically a solitary mass on one side of the neck, and is usually found near the carotid sheath. Some cervical thymic cysts may extend into the mediastinum. It is usually asymptomatic. The diagnostic process includes differentiating between other causes of neck masses in infants and children, including branchial cleft cysts and cystic hygromas. The treatment is surgical excision. On histologic examination, the wall of the cyst includes thymic tissue, and may include parathyroid gland tissue because of the parathyroid gland's common embryonic origin with the thymus gland in the third pharyngeal pouch. Fewer than 100 cases of cervical thymic cysts have been reported in the medical literature.

References

  1. 1 2 "Neurogenic Tumors of the Mediastinum" . Retrieved 28 July 2012.
  2. Macchiarini P, Ostertag H (February 2004). "Uncommon primary mediastinal tumours". Lancet Oncol. 5 (2): 107–18. doi:10.1016/S1470-2045(04)01385-3. PMID   14761815.
  3. Davis RD, Oldham HN, Sabiston DC (September 1987). "Primary cysts and neoplasms of the mediastinum: recent changes in clinical presentation, methods of diagnosis, management, and results". Ann. Thorac. Surg. 44 (3): 229–37. doi: 10.1016/S0003-4975(10)62059-0 . PMID   2820323.
  4. Kuo TT (2001). "Classification of thymic epithelial neoplasms: a controversial issue coming to an end?". J. Cell. Mol. Med. 5 (4): 442–8. doi:10.1111/j.1582-4934.2001.tb00182.x. PMC   6740057 . PMID   12067481.
  5. Rosenwald A, Wright G, Leroy K, et al. (September 2003). "Molecular diagnosis of primary mediastinal B cell lymphoma identifies a clinically favorable subgroup of diffuse large B cell lymphoma related to Hodgkin lymphoma". J. Exp. Med. 198 (6): 851–62. doi:10.1084/jem.20031074. PMC   2194208 . PMID   12975453.
  6. Rodríguez J, Gutiérrez A, Piris M (June 2008). "Primary mediastinal B-cell lymphoma: treatment and therapeutic targets". Leuk. Lymphoma. 49 (6): 1050–61. doi:10.1080/10428190801958994. PMID   18452109. S2CID   24939529.
  7. Savage KJ (May 2006). "Primary mediastinal large B-cell lymphoma". Oncologist. 11 (5): 488–95. doi: 10.1634/theoncologist.11-5-488 . PMID   16720849.
  8. Turgeon, Mary Louise (2005). Clinical hematology: theory and procedures. Hagerstown, MD: Lippincott Williams & Wilkins. p. 283. ISBN   978-0-7817-5007-3. Frequency of lymphoid neoplasms. (Source: Modified from WHO Blue Book on Tumour of Hematopoietic and Lymphoid Tissues. 2001, p. 2001.)
  9. 1 2 Cabot, Richard C (1919). Physical diagnosis (7th ed.). New York: William Wood and Company. p. 527.