Methods and materials: We assessed 22 embryonic, 17 foetal and 90 adult spleens on the presence of clefts using histology, micro-CT and conventional post-mortem CT-scans, respectively.
Results: The spleen primordium was observed as a single mesenchymal condensation in all embryonic specimens. The number of clefts varied from 0 to 6 in foetuses, compared to 0-5 in adults. We found no correlation between foetal age and number of clefts (R2 = 0.004). The independent samples Kolmogorov-Smirnov test showed no significant difference in the total number of clefts between adult and foetal spleens (p = 0.068).
Conclusion: We found no morphological evidence for a multifocal origin or a lobulated developmental stage of the human spleen.
Advances in knowledge: Our findings show that splenic morphology is highly variable, independent of developmental stage and age. We suggest to abandon the term "persistent foetal lobulation" and to regard splenic clefts, regardless of their number or location, as normal variants.