Quantifying Macrophages and Hemosiderin in Pediatric Dura Mater

Determining the age of a subdural hematoma at autopsy is of great interest for medicolegal purposes. The appearance of pigment-laden macrophages is often referenced as evidence that the subdural hematoma is 3-4 days old. However, understanding the significance of macrophages and hemosiderin requires understanding the histology of infant dura. Samples of grossly unremarkable dura taken from 17 pediatric autopsies were identified and histologically confirmed to lack subdural neomembrane. CD68 immunostaining and Prussian blue staining was performed. The CD68-positive cells per high-power field were quantified, and the presence of iron-containing cells was recorded. CD68-positive cells were present in all cases, even in the dural border layer. Iron-containing cells were identified in 59% of cases, and in the dural border layer in 29%. Therefore, CD68-positive and iron-containing cells can be present in pediatric dura without neomembrane or macroscopic subdural hemorrhage, and this requires consideration when estimating the age of a subdural hematoma.