Related Experiment Video
Updated: Aug 7, 2026
Isolation, Identification, and Purification of Murine Thymic Epithelial Cells
Published on: August 8, 2014
Structural heterogeneity and immunohistochemical profile of Hassall corpuscles in normal human thymus
Marius Raica1, Svetlana Encică, Andrei Motoc
1Department of Histology, Victor Babes University of Medicine and Pharmacy, Piata Eftimie Murgu 2, 300041 Timisoara, Romania. raica@umft.ro
Insights
Hassall corpuscles in the thymus exhibit distinct morphological types and express specific proteins. These findings suggest their active role in thymocyte differentiation, mediated by S100-positive dendritic cells.
Area of Science:
- Immunology
- Cell Biology
- Histology
Background:
- The thymus is crucial for T-cell maturation, involving thymocyte selection.
- Hassall corpuscles are unique thymic structures of epithelial origin.
- Their precise role in thymocyte selection remains incompletely understood.
Purpose of the Study:
- To investigate the morphological and immunohistochemical characteristics of Hassall corpuscles.
- To explore the potential involvement of Hassall corpuscles in thymocyte selection.
Main Methods:
- Analysis of 27 normal thymus specimens using histological and immunohistochemical techniques.
- Evaluation of cytokeratin profiles, S100, CD45, CD20, CD3, CD68, CD34, chromogranin A, neuronal-specific enolase, and desmin.
- Classification of Hassall corpuscles into four types: juvenile, immature, mature, and senescent.
Main Results:
- Four distinct morphological types of Hassall corpuscles were identified.
- Polyclonal cytokeratins were consistently positive in epithelial cells, with high-molecular-weight cytokeratin strong in mature corpuscles.
- S100-positive dendritic cells were abundant in juvenile and immature corpuscles, while CD20 and CD3 cells were found around corpuscles.
Conclusions:
- Hassall corpuscle morphology varies with age and type.
- The presence of S100-positive dendritic cells and surrounding immune cells suggests Hassall corpuscles actively modulate thymocyte differentiation.
- Epithelial cells of Hassall corpuscles, particularly via S100-positive dendritic cells, play a role in medullary thymocyte selection.
Abstract:
The study was conducted on 27 specimens of normal thymus, removed during surgery for cardiovascular malformations. Biopsies were processed using current histological techniques, and the samples were stained using morphological and immunohistochemical methods (cytokeratin profile, vimentin, S100, CD45, CD20, CD3, CD68, CD34 protein, chromogranin A, neuronal-specific enolase, desmin). Microscopic examination focused on the structure and immunohistochemical profile of Hassall corpuscles, beginning from the hypothesis that the epithelial cells of these structures, characteristic for the thymus, participate in the negative and positive selection of thymocytes. Morphological assessment revealed the existence of four different types of Hassall corpuscles: juvenile, immature, mature and senescent. The lymphocyte-rich variant was identified in 25.92% of the cases with ages ranging between 7 days and 12 years. From the immunohistochemical point of view, the following reactions were negative: cytokeratins 7 and 8, vimentin, desmin, CD3, CD68, CD34 and neuron-specific enolase. Isolated positive chromogranin cells were found in two cases, and positive intracorpuscular CD20 cells in one case. Polyclonal cytokeratins were positive in all instances in the epithelial cells of the Hassall corpuscles, with higher intensity in high-molecular weight cytokeratin, strongly expressed in mature corpuscles. All specimens had positive S100 cells in the corpuscles, distributed among the epithelial cells, with dendritic morphology, in great numbers in juvenile and immature forms. Morphological and immunohistochemical results (corpuscle variants, the presence of positive S100 cells, concentration of positive CD20 and CD3 cells around the corpuscles) suggest the active involvement of epithelial cells of Hassall corpuscles in modulating the differentiation of thymocytes at the medullar level, a process that is mediated by protein S100 positive corpuscular dendritic cells.
More Related Videos
07:32Mast Cells in the Microenvironment of Hepatocellular Carcinoma Confer Favorable Prognosis: A Retrospective Study using QuPath Image Analysis Software
Published on: April 12, 2024
07:54Heterogeneity Mapping of Protein Expression in Tumors using Quantitative Immunofluorescence
Published on: October 25, 2011