[Large accessory spleen torsion with a distorted fascicular structure; a case report].

A 37-year-old woman was admitted with left upper quadrant pain. Imaging examinations revealed a cystic mass with a diameter of 70 mm near the tail of the pancreas. The mass had a distorted fascicular structure adjacent to the hilum of the spleen. On operation the distorted fascicular structure was revealed to be connective tissue including vessels. On histopathological examination, the mass was strongly suspected to be an accessory spleen because spleen-like stroma was recognized, in spite of degeneration due to infarction.