A midline prepontine cyst: Serial magnetic resonance imaging over 20 years shows very slow growth after its rapid shrinkage

Prepontine intracerebral cyst with spontaneous resolution

Background:

Intracranial cysts in the prepontine region are rare and can lead to various complications if not managed appropriately. Symptomatic prepontine cysts may require surgical intervention. However, spontaneous resolution of such cysts is rarely reported in literature.

Case Description:

We describe the case of a middle-aged lady who presented with headaches and imbalance, with no focal neurological deficits on examination. Magnetic resonance imaging (MRI) of the brain showed a prepontine cyst compressing the brainstem with craniocaudal extension through the foramen magnum. The patient was given symptomatic treatment and followed closely with repeat MRI scans. These scans showed regression and eventual disappearance of the lesion, with complete resolution of symptoms.

Conclusion:

In light of the few reported cases of spontaneous resolution of prepontine cysts, we highlight the possibility of these lesions to self-resolve.

Endodermal Cyst with a Non-enhancing Nodule in the Quadrigeminal Cistern Developed in an Octogenarian

BACKGROUND

Intracranial endodermal cysts are congenital lesions that generally develop in the cerebellopontine angle and ventral brainstem of the posterior fossa, whereas endodermal cysts in the quadrigeminal cistern are very rare. We report a rare case of an endodermal cyst in the quadrigeminal cistern with a non-enhancing nodule that developed in patient over 80 years of age.

CASE DESCRIPTION

An 85-year-old man presented to our hospital with progressing gait disturbance and urinary incontinence. Preoperative images showed a cystic mass lesion with a nodule in the quadrigeminal cistern and hydrocephalus. There was no enhanced portion in the lesion, and the intensity of the cyst on magnetic resonance imaging revealed a high protein concentration. Subtotal resection was performed due to the adhesion of the cyst to the brainstem. It was diagnosed as an endodermal cyst. The postoperative course was uneventful, and hydrocephalus improved.

CONCLUSIONS

This is a rare case of an intracranial endodermal cyst in terms of location and age of onset compared with previous reports. This case demonstrates that endodermal cysts should be considered as a differential diagnosis for lesions in the quadrigeminal cistern with high protein concentration in the cyst and nodule representing chronic inflammation, regardless of enhancing effects.