Miastenia y timoma en una niña de 7 años

Introduction. Myasthenia is an autoimmune disease, being generalized muscular weakness, with important participation of facial muscles, a prominent feature. Signs of muscular fatigue arise, worsened by exercise and alleviated by rest. Clinical symptoms are less marked before noon, andgetworse as the day advances, through the afternoon and evening. A clear relationship between myasthenia and tymic abnormalities does exist, being glandular hyperplasia and tumours the commonest underlying pathologic findings. Initial treatment is based on anticholinesterase drugs and steroids. Non respondents should be treated with immunoglobulins, immunosuppresses, plasmapheresis and surgical removal of the tymus, according to the symptoms control. Case report. We present the case of a seven years old girl with generalized muscular weakness, worsening through the day, being the diagnosis ofmyasthenia confirmed by the high level of acetylcholine antireceptors antibodies and the neurophysiologic study. Imaging study of the mediastinum showed a tymic mass located in the right lobe. Conclusion. It is therefore most important to rule out these conditions when myasthenia is suspected.