- THYMIC LYMPHOMA
- AVIAN RETROVIRUS
- Armed Forces Institute of Pathology
- While they do not have lymph nodes, birds do have a thymus (in their neck as seen here) which is the site of T-cell development, as well as a Bursa of Fabricius, the site of B-cell development. Avian leukosis virus often causes B-cell tumors in the hematolymphatic organs. On a practical basis, there is no wayto definitively establish whether avian retroviruses (lymphoid leukosis, reticuloendotheliosis), or avian herpesvirus-1 (Marek's disease) is the cause of this tumor on gross or histologic inspection. At best, it is a educated guess (but still a guess).