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