**1. Introduction**

Dysphagia is one of the symptoms in patients with connective tissue diseases (CTDs), although it is not directly fatal and is a frequent complication. The frequency of esopha‐ geal dysmotility is 46-92%, 30-88%, 21-72%, and 50% in patients with systemic sclerosis (SSc), mixed connective tissue disease (MCTD), systemic lupus erythematosis (SLE), and polymyositis/dermatomyositis (PM/DM), respectively [1-8]. While the cause of esophageal dysfunction in patients with CTDs has been unclear, there are some reports that suggest the accumulation of extracellular matrix, neuropathy, and autoantibody as the cause of esophageal dysfunction in patients with SSc [9-11]. On the other hand, there are few reports relating to the cause of esophageal dysfunction in MCTD patients, despite its frequency. Therefore, we examined the histopathological characteristics of esophageal lesions in MCTD patients using 27 autopsy cases in Japan [12].
