Fig. 1
![Fig. 1](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs40792-020-00939-1/MediaObjects/40792_2020_939_Fig1_HTML.png)
Anterior mediastinal mass. Chest computed tomography (CT) revealed a 2.5-cm well-defined homogenous mass in the anterior mediastinum at the time of diagnosis with autoimmune pancreatitis (a), and the tumor decreased in size to 2 cm on CT with oral steroid treatment 6 years ago (b). The tumor had regrown to 3 cm at the time of referral to our department on CT (c, d), and positron emission tomography showed a high maximum standardized uptake of 3.6 by the anterior mediastinal mass lesion (e)