Morphology of pancreatic tissue-containing accessory spleen in an APA hamster

Accessory spleen (AS) was observed in 19 out of 71 (27%) golden hamsters of APA strain autopsied in the Institute of Physical and Chemical Research. When these AS were examined histologically, clusters of pancreatic tissues, such as islets and acini, were detected in the parenchyma of one AS located in the tail of pancreas of a 15-week-old male animal. This heterotopic pancreatic tissue was considered to penetrate deep into the AS from the pancreas through the adhesion site without any connective tissue border during the ontogenesis.