The proportions of the white and red pulps of the human fetal spleen

OBJECTIVE: To compare the proportions of white and red pulps of the human spleen during the fetal period.

METHODS: We performed this study in the Department of Anatomy and Pathology of Suleyman Demirel University, Faculty of Medicine, Isparta, Turkey, from the period between 2002-2003. Spleens from 137 dead fetuses aged between 9 and 40 weeks were embedded into paraffin blocks following classical histological steps and stained with hematoxylin and eosin. White and red pulps could be differentiated only in 25 cases (13 males, 12 females). The proportions of the areas of white and red pulps (the trabeculae were included into the red pulp and the groups of lymphocytes were included into the white pulp) were estimated by point counting method on the sections taken from different parts of the spleens by systematic randomized sampling technique.

RESULTS: It has been ascertained that the white pulp has been distinguished from 20th week onwards during the fetal period. The proportion of the white pulp area has been found to be 22.3% (of total white and red pulp areas) at the 20th week and has come to 37.6% at the 40th week. Concerning the trimesters, the proportion of the white pulp area has been found to be 30% (of total white and red pulp areas) at the 2nd trimester and has come to 36% at full term. While the white pulp area had a positive correlation with the gestational age (r: 0.34), the red pulp area had a negative one (r: -0.34). No difference has been found among gender.

CONCLUSION: Reference values have been obtained about the proportions of white and red pulp areas of human fetal spleen.