(1) Occurring naturally and normally in a certain type of tissue or in a specific structure of the body. (2) In transplantation, referring to transfer of an organ or other tissue from one location to another in the same person; or to blood or blood components that the donor has previously donated and receives at a later time, usually perioperatively.autotransfusion (3) Rarely used to denote a neoplasm derived from cells that occur normally at that sight, e.g., a squamous cell carcinoma in the upper esophagus. SYN: autogenous (1). [auto- + G. logos, relation]