Possibly active persistent thymus found in a human adult cadaver - a morpho-histological study

Thymus is a bilobed organ usually situated in the superior mediastinum. Thymus is normally active until puberty and as age advances it undergoes considerable fibro-fatty degeneration and is replaced by fatty tissue. We found a persistent thymus in an adult male cadaver aged 70 years approximately. It apparently looked healthy. Hence the objective of this study was to know the morpho-histology of a persistent human thymus gland. Associated with this we also found a concurrent absence of isthmus of thyroid gland. Thymus obtained was processed according to the standard procedures and sections were stained with Haematoxylin & Eosin stain to study the age related changes of the thymus gland. Stained sections of thymus revealed a normal, healthy architecture of lobes of thymus. Knowledge regarding these morpho-histological features of the persistent thymus is important for clinicians and radiologists for the differential diagnosis of any mediastinal mass or presence of ectopic thymic tissue before doing any investigative procedure.