Histogenesis of Human Fetal Spleen at Different Gestational Ages

Introduction: Among the lymphoid organs, spleen is the largest one with rich blood supply. It serves to filter the blood, shows immune response to antigens and in fetal life acts as a haematopoietic organ to produce erythrocytes and granulocytes. As of known, the human lymphoid organs shows variations, spleen lacks the definite histogenetic changes. Aim: To find out the histogenesis of spleen in different gestational ages between normal pregnancy and hypertension in pregnancy, Materials and Methods: The present observational study was carried out on 100 human aborted and stillborn foetuses, aged between 12 to 40 gestational weeks. Out of 100 fetuses, 50 belonged to normal pregnancy and 50 belonged to hypertension in pregnancy. The foetuses were obtained from the Department of Obstetrics and Gynaecology and Department of Pathology. The tissue was processed, slides prepared and stained with Haematoxylin and eosin. The slides were observed under compound microscope using 4x,10x,40x and 100x objectives and interpreted. Results: The following microscopic features were observed in the present study at different gestational ages in normal pregnancy. At 12-18 weeks, spleen was lined by thin capsule, parenchyma with blood vessels, reticular cells and haematopoietic cells seen, at 17 weeks central arteriole started appearing. At 19 weeks trabeculae were seen, venous sinuses, central arteriole surrounded by few lymphocytes. 20-weeks; red and white pulp were seen, Peri-arteriolar lymphatic sheath was seen. At 24 weeks capsule was more thick with increased trabeculae. At 24-30 weeks germinal centre was seen along with the ring fibres. At 30-36 weeks, capsule was thick, white pulp was well defined. At 37 weeks, germinal centre was well-defined. At 38-40 weeks, the fetal spleen resembled that of an adult spleen. The present study attempted studying the histogenesis of fetal spleen in hypertension in pregnancy. The microscopic features of spleen did not show differences between normal pregnancy and that in hypertension in pregnancy. The study could not establish any comparable differences in the two situations. Conclusion: The present study served to study the splenic histogenesis to some extent. The findings in individual Author variations are still existing. The study could not conclude difference in the histogenesis of spleen in normal pregnancy and hypertension in pregnancy. This study may serve the Anatomists and the Pathologists for studying the individual variations in histogenesis of spleen.