<prompt> Which one of the following is closely associated with Myasthenia gravis?ThymomaLymphomaAdenomaNone  <response>: A Thymoma MYASTHENIA GRAVIS is a neuromuscular disorder characterised by weakness and fatigability of skeletal muscles. Up to 75 of patients have an abnormality of the thymus; 25 have a thymoma, a tumor either benign or malignant of the thymus, and other abnormalities are frequently found. The disease process generally remains stationary after thymectomy removal of the thymus. Disorders Associated with Myasthenia Gravis Recommended LaboratoryTests Associated disorders Disorders of the thymus: thymoma, hyperplasia Other autoimmune disorders: Hashimotos thyroiditis, Graves disease, rheumatoid arthritis, lupus erythematosus, skin disorders, family history of autoimmune disorder Disorders or circumstances that may exacerbate myasthenia gravis: hyperthyroidism or hypothyroidism, occult infection, mec ical treatment for other conditions aminoglycoside antibiotics, quinine, antiarrhythmic agents Disorders that may interfere with therapy: tuberculosis, diabetes, peptic ulcer, gastrointestinal bleeding, renal disease, hypertension, asthma, osteoporosis, obesity Recommended laboratory tests or procedures CT or MRI of mediastinum Tests for lupus erythematosus, antinuclear antibody, rheumatoid factor, antithyroid antibodies Thyroid-function tests PPD skin test Chest radiography Fasting blood glucose measurement Pulmonary-function tests Bone densitometry in older patients 