Miastenia gravis asociada a timoma con miopatía inflamatoria

Thymomas account for approximately 20 percent of mediastinal neoplasms. Most patients with thymoma are between 40 and 60 years of age, and there is a similar incidence in men and women. There are no known risk factors, although there is a strong association with myasthenia gravis and other paraneoplastic syndromes, including autoimmune myositis or encephalitis. Myasthenia gravis is the most common disorder associated with thymoma. The distinguishing feature of the disorder is a fluctuating degree and a variable combination of weakness in the ocular, bulbar, limb and respiratory muscles. Weakness is the result of an immune-mediated attack by T cells mediated by antibodies directed to the proteins in the postsynaptic membrane of the neuromuscular junction (acetylcholine receptors and/or receptor-associated proteins). The diagnosis of myasthenia gravis can be established by clinical and serological tests. The treatment of myasthenia will be the establishment of pyridostigmine or neostigmine, corticoids, plasmapheresis, depending on the severity of the disease, while the treatment of thymoma will depend on the stage of the same considering surgery, chemotherapy and/or radiotherapy.