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.