ABSTRACT
Introduction: Thymus is an asymmetrical bilobed mass of lymphoid tissue.It is the most important component of superior medistinum. Embryologically it develops as a bilobed structure from the third pharyngeal pouches of embryo in common with inferior parathyroid gland. It is clinically important for differential diagnosis of radiological review of mediastinal mass. Its persistence in adults, its embryological and anatomical features are necessary before doing any invasive procedures. Materials And Methods:The study was carried out on six embalmed formalin fixed cadavers of known age and sex in Anatomy Department of Kanyakumari Government Medical College, Nagercoil, Tamilnadu. A large bilobed thymus was found in a 40 year old male cadaver. Result And Conclusion: Thus we found a large bilobed thymus in 40 year old male cadaver.This fact is clinically important for radiologist to make differential diagnosis in case of mediastinal mass.A thorough knowledge of embryology and anatomy of the thymus,normal variations and ectopic location of thymus and its dynamic changes is neccesary before doing any therapeutic,diagnostic and invasive procedures.