Pineal cysts - a benign consequence of mild hypoxia in a near-term brain?

BACKGROUND Pineal cysts are benign glial uniloculated or multiloculated fluid-filled sacs located in the pineal gland region. Small pineal cysts are often found incidentally in healthy adults in 1.5-10.8%. Large cysts may cause neurological problems due to pressure exertion on adjacent structures. METHODS We have used prospective, observational study of an inception cohort of 16 adolescents of mean age 21.69 years (SD=±0.87) with mild (68.7%) to moderate (31.3%) HIE: 7 girls (43.8%) and 9 (56.3%) boys, born with mean gestational age of 35.75 weeks (SD=±3.80) and mean birthweight of 2 644 g (SD=±815). HIE was confirmed by presence of abnormal CTG and/or meconium and/or Apgar scores less than 7 at 5 minutes and/or need for resuscitation and/or cord pH less than 7.2 and /or BE more than -15. The clinical assessment of HIE was done according to the Sarnat-Sarnat scoring. Neonatal data, including EEG and imaging data, were collected. Adolescents were scanned with 3T Magnetom Trio Tim, Siemens, head coil 12 channels, regular sequences and sagittal 3D magnetization-prepared rapid acquisition gradient echo (MPRAGE) sequence with voxel size 1 mm3. Neurological outcome was determined. RESULTS In 1 patient we found cortical dysplasia and 1 had a panic attack hence their data were omitted. In the group of 14 we have incidentally found in 5 patients a larger, asymptomatic pineal cysts with the overall incidence of 36%. Other MR findings in the group were in 50% white matter injury, in 50% thinner corpus callosum. No statistically significant difference between neonatal cUS and late follow-up MRI (p=0.881) was found. Correlation was not significant with Spearman correlation coefficient 0.201. Presence of pineal cysts was linked to thinner corpus callosum (p=0.005). CONCLUSIONS We propose that larger pineal cyst, in the absence of other imaging findings except for thinner corpus callosum, is a benign consequence of mild hypoxia in a near-term brain. Our findings warrant a larger study.