Prognosis is much worse for stage III or IV thymomas as compared with stage I and II tumors. Invasive thymomas uncommonly can also metastasize, generally to pleura, bones, liver or brain in approximately 7% of cases. Patients with stage III and IV tumors may nonetheless survive for several years with appropriate oncological management.

Patients who have undergone thymectomy for thymoma should be warned of possible severe side effects after yellow fever vaccination. This is probably caused by inadequate T-cell response to live attenuated yellow fever vaccine. Deaths have been reported.

Men and women are equally affected by thymomas. The typical age at diagnosis is 30–40, although cases have been described in every age group, including children.

The mechanism for paraneoplastic syndrome varies from case to case. However, pathophysiological outcomes usually arise from when a tumor arises. Paraneoplastic syndrome often occurs alongside associated cancers as a result of activated immune systems. In this scenario, the body may produce antibodies to fight off the tumor by directly binding and destroying the tumor cell. Paraneoplastic disorders may arise in that antibodies would cross-react with normal tissues and destroy them.

The following diseases manifest by means of physiological dysfunction besides the categories above: membranous glomerulonephritis, tumor-induced osteomalacia, Stauffer syndrome, Neoplastic fever, and thymoma-associated multiorgan autoimmunity. Rheumatologic (hypertrophic osteoarthropathy), renal (secondary kidney amyloidosis and sedimentation of immunocomplexes in nephrons), and gastrointestinal (production of molecules that affect the motility and secretory activity of the digestive tract) dysfunctions, for example, may relate to paraneoplastic syndromes.

Thymus hyperplasia (or thymic hyperplasia) refers to an enlargement ("hyperplasia") of the thymus.

It is not always a disease state. The size of the thymus usually peaks during adolescence, and atrophies in the following decades. Before the immune function of the thymus was well understood, the enlargement was sometimes seen as a cause for alarm, and justification for surgical reduction. This approach is much less common today.

It can be associated with myasthenia gravis.

MRI can be used to distinguish it from thymoma.

Patients often have a refractory disease course but some patients may respond to phototherapy.

Thymic carcinoma is a rare type of thymus gland cancer. It usually spreads, has a high risk of recurrence, and has a poor survival rate. Thymic carcinoma is divided into subtypes, depending on the types of cells in which the cancer began. Also called type C thymoma.

Thymoma-associated multiorgan autoimmunity (TAMA) is a severe often fatal disease that presents in some patients with thymoma. It has also been referred to in the medical literature as "thymoma-associated graft-versus-host-like disease".

Thymoma with immunodeficiency (also known as "Good syndrome") is a condition that occurs in adults in whom hypogammaglobulinemia, deficient cell-mediated immunity, and benign thymoma may develop almost simultaneously.

Good Syndrome (GS) is a rare primary immunodeficiency. It is broadly defined as hypogammaglobulinemia associated with presence of a thymoma. It presents in adulthood with an anterior mediastinal mass and recurrent sinopulmonary infections.

The syndrome has been diagnosed around the globe with a focus in Europe. The incidence of thymoma in the United States is 0.15 cases per 100,000 and of these patients, approximately 6-11% have concurrent hypogammaglobulinemia (Kelesidis, 2010). It affects men and women equally and typically is diagnosed in the sixth decade of life, much later than other primary immunodeficiencies.

Dr. Robert Good recognized the association between thymoma and hypogammaglobulinemia in 1954. Since then, little has been discovered in regards to its pathogenesis.

This disease is more common in women and an association with the gene FLT4 has been described. FLT4 codes for VEGFR-3, which is implicated in development of the lymphatic system.

Milroy's disease is also known as primary or hereditary lymphedema type 1A or early onset lymphedema.

It is a very rare disease with only about 200 cases reported in the medical literature. Milroy's disease is an autosomal dominant condition caused by a mutation in the FLT4 gene which encodes of the vascular endothelial growth factor receptor 3 (VEGFR-3) gene located on the long arm (q) on chromosome 5 (5q35.3).

In contrast to Milroy's disease (early onset lymphedema type 1A,) which typically has its onset of swelling and edema at birth or during early infancy, hereditary lymphedema type II, known as Meige disease, has its onset around the time of puberty. Meige disease is also an autosomal dominant disease. It has been linked to a mutations in the ‘forkhead’ family transcription factor (FOXC2) gene located on the long arm of chromosome 16 (16q24.3). About 2000 cases have been identified. A third type of hereditary lymphedema, that has an onset after the age of 35 is known as lymph-edema tarda.

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 usually present in 40-50's with nodular sclerosing type (7), and non-Hodgkin's in all age groups. Can also be primary mediastinal B-cell lymphoma with exceptionally good prognosis. Common symptoms include fever, weight loss, night sweats, and compressive symptoms such as pain, dyspnea, wheezing, Superior vena cava syndrome, pleural effusions (10,11). 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. (12,13,14) Treatment of mediastinal Hodgkin's involves chemotherapy and/or radiation. 5 year survival is now around 75%. (15) Large-cell type may have somewhat better prognosis. Surgery is generally not performed because of invasive nature of tumor.

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

The cause of GS has not been discovered. The basic defect is most likely in the bone marrow and there is some evidence of autoimmune pathogenesis.

Risk factors for small intestine cancer include:

- Crohn's disease

- Celiac disease

- Radiation exposure

- Hereditary gastrointestinal cancer syndromes: familial adenomatous polyposis, hereditary nonpolyposis colorectal cancer, Peutz-Jeghers syndrome

- Males are 25% more likely to develop the disease

Benign tumours and conditions that may be mistaken for cancer of the small bowel:

- Hamartoma

- Tuberculosis

The precise symptoms of a primary immunodeficiency depend on the type of defect. Generally, the symptoms and signs that lead to the diagnosis of an immunodeficiency include recurrent or persistent infections or developmental delay as a result of infection. Particular organ problems (e.g. diseases involving the skin, heart, facial development and skeletal system) may be present in certain conditions. Others predispose to autoimmune disease, where the immune system attacks the body's own tissues, or tumours (sometimes specific forms of cancer, such as lymphoma). The nature of the infections, as well as the additional features, may provide clues as to the exact nature of the immune defect.

Meige lymphedema, also known as Meige disease, Late-onset lymphedema, and Lymphedema hereditary type 2, is an inherited disease in which patients develop lymphedema. The onset is between the ages of 1 and 35. Other causes of primary lympoedema include Milroy's disease which occurs before the age of 1, and lymphoedema tarda which occurs after the age of 35.

Meige disease,(Hereditary lymphedema type II), has its onset around the time of puberty. It is an autosomal dominant disease. It has been linked to a mutations in the ‘forkhead’ family transcription factor (FOXC2) gene located on the long arm of chromosome 16 (16q24.3). It is the most common form of primary lymphedema, and about 2000 cases have been identified. Meige disease usually causes lymphedema of the legs, however, other areas of the body may be affected, including the arms, face and larynx. Yellow toe nails occur in some individuals.

Primary immunodeficiencies are disorders in which part of the body's immune system is missing or does not function normally. To be considered a "primary" immunodeficiency, the cause of the immune deficiency must not be secondary in nature (i.e., caused by other disease, drug treatment, or environmental exposure to toxins). Most primary immunodeficiencies are genetic disorders; the majority are diagnosed in children under the age of one, although milder forms may not be recognized until adulthood. While there are over 100 recognized PIDs, most are very rare. About 1 in 500 people in the United States are born with a primary immunodeficiency. Immune deficiencies can result in persistent or recurring infections, autoinflammatory disorders, tumors, and disorders of various organs. There are currently no cures for these conditions; treatment is palliative and consists of managing infections and boosting the immune system.

Often AGID is a symptom of other problems, including colon cancer, lupus, lung, breast, or ovarian carcinoma or thymoma. or other diseases. Irritable bowel syndrome (IBS) is the most recognized form of AGID.

Autoimmune gastrointestinal dysmotility (AGID) is an autoimmune disease autonomic neuropathy affecting the gastrointestinal organs and digestive system of the body. Dysmotility is when the strength or coordination of the esophagus, stomach or intestines muscles do not work as they should.

Little research is conducted on these cancers due to their relative rarity when compared to the more common colorectal cancers. APC-min mice which carry a gene deficiency corresponding to that of humans with FAP also go on to develop small intestinal tumors, though humans do not.

Milroy's disease (MD) is a familial disease characterized by lymphedema, commonly in the legs, caused by congenital abnormalities in the lymphatic system. Disruption of the normal drainage of lymph leads to fluid accumulation and hypertrophy of soft tissues. It is also known as Milroy disease, Nonne-Milroy-Meige syndrome and hereditary lymphedema.

It was named by Sir William Osler for William Milroy, a Canadian physician, who described a case in 1892, though it was first described by Rudolf Virchow in 1863.

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. 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. (3,4) 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 12-54% regardless of any myasthenia gravis symptoms (5,6).

Hereditary cancer syndromes underlie 5 to 10% of all cancers. Scientific understanding of cancer susceptibility syndromes is actively expanding: additional syndromes are being found, the underlying biology is becoming clearer, and commercialization of diagnostic genetics methodology is improving clinical access. Given the prevalence of breast and colon cancer, the most widely recognized syndromes include hereditary breast-ovarian cancer syndrome (HBOC) and hereditary non-polyposis colon cancer (HNPCC, Lynch syndrome).

Some rare cancers are strongly associated with hereditary cancer predisposition syndromes. Genetic testing should be considered with adrenocortical carcinoma; carcinoid tumors; diffuse gastric cancer; fallopian tube/primary peritoneal cancer; leiomyosarcoma; medullary thyroid cancer; paraganglioma/pheochromocytoma; renal cell carcinoma of chromophobe, hybrid oncocytic, or oncocytoma histology; sebaceous carcinoma; and sex cord tumors with annular tubules. Primary care physicians can identify people who are at risk of heridatary cancer syndrome.

Acropachy or thyroid acropachy refers to a dermopathy associated with Graves' disease. It is characterized by soft-tissue swelling of the hands and clubbing of the fingers. Radiographic imaging of affected extremities typically demonstrates periostitis, most commonly the metacarpal bones. The exact cause is unknown, but it is thought to be caused by stimulating auto-antibodies that are implicated in the pathophysiology of Graves' thyrotoxicosis. There is no effective treatment for acropachy.

Since it is closely associated with Graves' disease, it is associated with other manifestations of Graves' disease, such as Graves' ophthalmopathy and thyroid dermopathy.

Hereditary acropachy (also known as "isolated congenital nail clubbing") may be associated with HPGD.

A cancer syndrome or family cancer syndrome is a genetic disorder in which inherited genetic mutations in one or more genes predispose the affected individuals to the development of cancers and may also cause the early onset of these cancers. Cancer syndromes often show not only a high lifetime risk of developing cancer, but also the development of multiple independent primary tumors. Many of these syndromes are caused by mutations in tumor suppressor genes, genes that are involved in protecting the cell from turning cancerous. Other genes that may be affected are DNA repair genes, oncogenes and genes involved in the production of blood vessels (angiogenesis). Common examples of inherited cancer syndromes are hereditary breast-ovarian cancer syndrome and hereditary non-polyposis colon cancer (Lynch syndrome).

Slone's disease is a specific form of hereditary pancreatitis. It is a rare inherited condition characterized by recurrent episodes of acute pancreatitis attacks. In about half of these cases the problem progresses to chronic pancreatitis, which is severe scarring of the pancreas. Laboratory tests performed during an attack usually detect high blood levels of amylase and lipase, which are enzymes released from the pancreas.

The first attack typically occurs within the first two decades of life, but can begin at any age. In the United States, the majority of Slones patients have a lineage which can be traced back to Appalachia. It is estimated that at least 1,000 individuals are newly diagnosed with hereditary pancreatitis each year. As genetic testing increases, these numbers may escalate.