A Conundrum of Colliding Conditions: A Histopathological Case Report of Chiari Type III with Complete Spina Bifida Aperta.

Background and Clinical Significance: Spina bifida in the cervical region is closely associated with Chiari malformation, which is an amalgamation of terminology for separate conditions with similar pathophysiological mechanisms and progression from one another. Chiari malformations are associated with varying degrees of dilation of the foramen magnum or lack of fusion of the occipital bone with syringomyelia, herniation of the cerebellum, occipitocele and occipitomyelocele; Case Presentation: A previously healthy 23-year-old primigravida presented to our institution due to fetal demise in the third lunar month, established on routine outpatient maternal consultation. Point-of-care ultrasound revealed an amniotic sac measuring 3 cm in diameter and containing a single fetus, without cardiac function. Due to these, the patient was scheduled for pregnancy termination, during which the cervix was noted to be spontaneously dilated and abrasion accomplished complete evacuation of the amniotic sac, without its rupture. Upon sectioning of the amniotic sac, a fetus, measuring 2.5 cm in length, was noted, with a significant cuffing of the occipital and cervical paraspinal region. Histology revealed fetal structures with an adequate maturation index for its gestational age, but it presented with a pronounced meningoencephalomyelocele in the cervical and thoracic regions, characterized by the complete absence of vertebral arches and spinous processes from the atlanto-occipital to the sacral region; Conclusions: In the present case, not only is a significant and complex form of Chiari type III reported, but the condition is also associated with spina bifida aperta in all spinal regions, leading to meningoencephalomyelocele, incompatible with life.