“Histogenesis of Human Fetal Spleen at Different Weeks of Gestational Age”

Background: The spleen is the largest lymphoid organ with a rich blood supply. It appears approximately in the 6th week of gestation as a thickening of the coelomic epithelium of the dorsal mesogastrium near its cranial end. The underlying angiogenetic mesenchyme becomes vascularised and compacted due to the invasion of proliferating cells. The process takes place concurrently in multiple adjacent regions, which quickly unite to produce a lobulated spleen. During the third month of pregnancy, the spleen acquires its final morphological form, and its size progressively grows. Aims: The study provides detailed knowledge about the cellular changes of the human fetal spleen. It also suggests the functional status of the spleen in the fetal period. Materials and Methods: This study was conducted on 76 human fetuses (40 males and 36 females), 10% formalin-fixed fetuses with gestational ages ranging from 12 to 36 weeks in the Department of Anatomy, DVVPF’s Medical College Campus, Ahilyanagar, and the Department of Pathology, Shree Narayan Medical Institute and Hospital, Saharsa. Results: In the present study, immature types of lymphocytes were seen at 11th weeks of GA, Number and maturity of lymphocytes were growing with age advancement. Up to the 14th weeks lymphocytes were arranged irregular manner. At 15th weeks onwards, lymphocytes start appearing around some arterioles, and lymphatic nodules were ill-define. Till the 18th week of GA, there is undifferentiated white and red pulp. At the 19th week, lymphocytes were present around the central arterioles, and lymphatic nodules were well defined at the same time, white pulp and red pulps were ill defined. Conclusion: we conclude from our study that the capsule, trabeculae, and cells of white and red pulp showed variations at different age groups. A thorough understanding of the histogenesis of the human fetal spleen is also provided by this study. Additionally, it implies the spleen's functional state during the fetal stage. DOI: https://doi.org/10.52783/jchr.v16.i1.11501