Morphological structure of accessory spleen in Chinese hamsters.

Yoon YS, Shin JW, Park CB, Oh YS, Lee IS, Lee HS, Lee JS.

College of Veterinary Medicine and School of Agricultural Biotechnology, Seoul National University, Suwon 441-744, Korea.
Department of Veterinary Medicine, Kangwon National University, Chunchon 200-701, Korea.
Experimental Animal Center, College of Medicine, Hallym University, Chunchon 200-702, Korea.

To attempt a rigorous definition of the structure of the accessory spleen (AS) in the Chinese hamster, we examined twenty-one animals, and found AS in 5 animals (23.8%), which were over 7-month-old. The AS had no connection with the main spleen and was seen as a dark red oval organ (0.7 mm x 1.5 mm), which was embedded in the adipose tissue near the tail of the pancreas. It was demarcated from the adipose tissue and some pancreatic tissue. The organ was encapsulated by thin collagenous connective tissue and smooth muscle fibers, and contained lymphatic nodules, reticular fibers, nodular central arterioles, macrophages and megakaryocytes. Notably the incidence of AS appeared to increase with age in the Chinese hamsters.