Cytoplasmic changes in bone marrow cells as indicators of postmortem interval

Accurate estimation of the postmortem interval (PMI) remains one of the central challenges in forensic medicine. Traditional external markers are limited by environmental and individual variability. Bone marrow, owing to its protected anatomical location and slower decomposition rate, offers a potential histological substrate for PMI estimation.

This study aimed to evaluate cytoplasmic changes in sternal bone marrow cells and assess their correlation with Postmortem interval (PMI).

A descriptive cross-sectional study of 43 medico-legal autopsies with documented time of death. Sternal bone marrow aspirates were stained with Leishman stain and examined microscopically. Cytoplasmic changes were scored from 0 to 4 (intact morphology to complete dissolution) using a system adapted from Biradar G et al. Data were analyzed using ANOVA (p < 0.05).

Mild cytoplasmic alterations (S1) were most frequent (51.1%), followed by moderate changes (S2, 25.6%) and severe dissolution (S4, 14%). Only 9.3% of cases showed no observable changes (S0). Mean PMI increased with the severity of cytoplasmic changes (S0: 8.5 h; S1: 14.1 h; S2: 10.5 h; S4: 15.0 h), although some overlap was seen, especially at S2, likely reflecting biological and environmental variability. The overall correlation was not statistically significant (p > 0.05).

Cytoplasmic autolysis in bone marrow appears to follow a progressive pattern, from early vacuolation to complete dissolution with increasing PMI. Although not statistically significant, observed trends suggest cytoplasmic scoring may aid early PMI estimation when combined with other markers.