[single, unpaired primary lymphoid organ situated in the mediastinum; it is necessary for normal development of immunologic function early in life but by puberty it begins to involute and much of the tissue is replaced by fat. ( CSP )]
UMLS (NCI) C0040113 - Body Part, Organ, or Organ Component
Relation/PAR: Body System, Endocrine/Metabolic
lymphatic tissue
Body Part