A Rare Association between Myasthenia Gravis and a Growth Hormone Secreting Pituitary Macroadenoma: A Single Case Report

Myasthenia Gravis (MG) is a chronic autoimmune neuromuscular disease. Although it is well known that patients with myasthenia gravis have a higher incidence of other autoimmune disorders, however, its association with pituitary adenomas is extremely rare. We believe that our case represents the 8^th of this association and the 2^nd case involving a GH-secreting adenoma. Here we report a case of a 45-year old Syrian woman who presented with typical complaints of myasthenia gravis as she was suffering from variable painless and effort-related dysphagia and dysarthria. Her complaints became more evident at the end of the day, while acromegaly only manifested as a 4-month history of headache and a special facies that was noted by the physician. Brain MRI scan demonstrated a 3.21 x 2.42 x 2.35 cm pituitary mass for which the patient underwent a trans-sphenoidal pituitary tumor resection. In addition, postoperative histopathological investigations confirmed the diagnosis of a GH-secreting macroadenoma. On following up, it was observed that her myasthenic symptoms improved significantly on Pyridostigmin and Prednisolone. In conclusion, the presence of headache in a myasthenic patient should raise the attention for other underlying causes including pituitary tumors.