foramen of Monro

Axial non-contrast CT scan revealed bilateral subependymal calcific nodules around the foramen of Monro and lateral ventricles

On rare occasion, they can cause sudden neurological deterioration, coma and subsequent death as a result of herniation due to complete and irreversible obstruction of foramen of Monro. Their removal poses a formidable challenge due to its deep location and intimate relationships with neural and vascular structures as well as hypothalamic-pituitary axis.

Nodular lesion in the region of foramen of Monro on the left suggestive of Subependymal giant cell astrocytoma.

Precontrast images demonstrated a well-defined, rounded, hyperdense lesion at the level of the foramen of Monro causing moderate dilatation of the lateral ventricles.

Any of these phenomena can cause rapid increase in the size of a colloid cyst resulting in acute obstruction of CSF flow at the foramen of Monro. Haemorrhage into a colloid cyst is another extremely rare phenomenon.

This World Health Organization (WHO) grade II neoplasm usually presents with signs of increased intracranial pressure secondary to obstructive hydrocephalus in young adults, since the tumor is typically located within the lateral ventricles in the region of the foramen of Monro. (2) Intratumoral hemorrhage has been described with the initial presentation.

A location in the foramen of Monro disturbs cerebrospinal fluid circulation.

A non-contrast computed tomography (CT) head exam demonstrated a hyperdense midline intraventricular lesion located along the septum pellucidum, extending into the frontal horns of both lateral ventricles and to the level of the foramen of Monro (Figure 1).

(6) We present a rare case report of a subependymoma at the foramen of Monro presenting with intermittent hydrocephalus.