Megaesophagus associated with Myasthenia Gravis: a rare condition in humans.

We present the case of a 79 year-old patient with megaesophagus and aphagia, who required percutaneous endoscopic gastrostomy (PEG) feeding. Megaesophagus was considered the sole cause of aphagia by the referring secondary hospital. Solid state sensor videofluoromanometry (VFM) showed a substantial decrease in manometric values within the hypopharynx along with good relaxation of the upper-esophageal sphincter (UES). This led to electromyography (EMG), which showed features compatible with the diagnosis of Myasthenia Gravis (MG). The diagnosis of MG was confirmed by an intravenous injection of edrophonium chloride, performed under VFM monitoring. The co-existence of MG and megaesophagus rarely occurs in humans; although, most small animals, such as dogs, cats, and rodents, present with megaesophagus as an initial symptom of MG.