Myasthenia gravis is most commonly associated with which of the following?: (A) Thymoma, (B) Thymic carcinoma, (C) Thymic hyperplasia, (D) Lymphoma
Answer is C. Myasthenia gravis Autoimmune disease with fluctuating muscle weakness that is caused by autoantibodies that target the neuromuscular junction. About 85% of patients have autoantibodies against post-synaptic ACh receptors, while most of the remaining patients have antibodies against the sarcolemmal protein muscle-specific receptor tyrosine kinase. C/F: - Ptosis or diplopia (Weakness in extraocular muscle) There is a strong association between pathogenic anti-ACh receptor autoantibodies and thymic abnormalities. Approximately 10% of patients with myasthenia gravis have a thymoma, a tumour of thymic epithelial cells. An additional 30% of patients (and paicularly young patients) have a different thymic abnormality called thymic hyperplasia. Acetylcholinesterase inhibitors that increase the half-life of ACh are the first line of treatment.