A Cyst of Benign Mediastinal Teratoma Demonstrating a Peculiar Development : Report of a Case

A 28-year-old woman developed repeated neck swelling and remission over a 4-month period. Benign mediastinal teratomas also extended along her cervical region. It was not a teratoma which primarily developed in the neck. In this case, rich pancreatic tissue was histologically observed. The mechanism of the particular extension of the tumor considered to be: (1) an encasement by anatomical structures and the right-sided hard wall of the tumor, and (2) pancreatic tissue which developed cystic formation.