Differential Diagnosis for Enlarged Cavum Septum Pellucidum in a Fetus
Single Most Likely Diagnosis
- Normal Variant: An enlarged cavum septum pellucidum can be a normal variant in fetal development. The cavum septum pellucidum is a fluid-filled space that is present in the midline of the brain, and its size can vary among fetuses.
Other Likely Diagnoses
- Agenesis of the Corpus Callosum: This condition involves the partial or complete absence of the corpus callosum, which is the major connecting structure between the two hemispheres of the brain. An enlarged cavum septum pellucidum can be associated with this condition.
- Holoprosencephaly: A disorder characterized by the failure of the brain to properly divide during fetal development, which can lead to an enlarged cavum septum pellucidum among other brain abnormalities.
- Arachnoid Cysts: These are fluid-filled sacs that can occur in the brain and may cause an enlargement of the cavum septum pellucidum if they are located in this area.
Do Not Miss Diagnoses
- Dandy-Walker Malformation: A condition characterized by an enlargement of the fourth ventricle and hypoplasia of the cerebellar vermis. While it primarily affects the posterior fossa, it can have associated midline abnormalities, including an enlarged cavum septum pellucidum.
- Hydrocephalus: An accumulation of cerebrospinal fluid within the brain, leading to increased intracranial pressure. It can cause various degrees of ventricular enlargement, including the cavum septum pellucidum.
Rare Diagnoses
- Septo-Optic Dysplasia: A rare congenital disorder involving underdevelopment of the optic disk, pituitary gland, and parts of the brain, including the septum pellucidum.
- Schizencephaly: A rare congenital disorder characterized by abnormal slits or clefts in the cerebral hemispheres, which can be associated with an enlarged cavum septum pellucidum in some cases.