[Myasthenia and thymoma in a seven year old girl]. / Miastenia y timoma en una niña de 7 años.

ABSTRACT

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, and get worse as the day advances, through the afternoon and evening. A clear relationship between myasthenia and thymic 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 thymus, 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 of myasthenia confirmed by the high level of acetylcholine antireceptors antibodies and the neurophysiologic study. Imaging study of the mediastinum showed a thymic mass located in the right lobe. CONCLUSION: It is therefore most important to rule out these conditions when myasthenia is suspected.