The organ is called the pancreas, but medical researchers refer to the endocrine pancreas and the exocrine pancreas as if they were different. The organ affected in diabetes is the endocrine pancreas. The shape of this organ is unusual; it is an archipelago, with clusters of cells distributed through the pancreas. The islets are concentrated in the tail of the pancreas. The larger islets look like small grains of sand, and the smaller islets look like mist.