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 8th of this association and the 2nd 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.