POLYMORPHISM OF HASSALL’S CORPUSCLES IN HUMAN FETAL THYMUS: A MORPHOLOGICAL AND HISTOLOGICAL ANALYSIS IN VARIOUS GESTATIONAL AGE GROUPS
Keywords:
fetal thymus, gestational age, Hassall’s corpuscles, medullary epithelium, thymic development, polymorphismAbstract
Background: Hassall’s corpuscles (HCs) are distinctive structures within the thymic medulla formed by concentric epithelial reticular cells. Their morphology and number vary significantly during fetal development, reflecting thymic maturation.
Aim: To analyze the polymorphism of Hassall’s corpuscles in human fetal thymus across three gestational age groups and correlate morphological changes with thymic development.
Material and Methods: Sixteen human fetuses aged 11–40 weeks were grouped into: Group I (11-20 weeks), Group II (21–30 weeks), and Group III (31–40 weeks). Thymuses were dissected following standard dissection norms, weighed, and evaluated histologically using H&E staining. Number, diameter, and morphological types of HCs were recorded. Polymorphism was classified as juvenile, premature, mature, advanced, solid, and cystic. Statistical analysis was performed using Student’s t‑test and Chi-square test.
Results: Significant increases were observed in number and diameter of HCs with advancing gestational age (p<0.001). Juvenile HCs predominated in Group I , while advanced types were maximal in Group III. Cystic transformation increased steeply in late gestation, reaching 90% in Group III.
Conclusion: Hassall’s corpuscles exhibit marked polymorphism during fetal development, with rapid maturation and cystic transformation after 30 weeks of gestation. Their diversity reflects progressive epithelial differentiation and thymic immunological maturation.
