Objective and importance: Endodermal cysts are rare lesions that primarily affect the spinal cord. Only a few reports have been published that describe intracranial endodermal cysts, and, in most of the cases, the cysts were located in the posterior fossa. To our knowledge, there have been no reports of endodermal cysts of the third ventricle.
Clinical presentation: A symptomatic endodermal cyst of the third ventricle in a 28-year-old man is presented. The patient demonstrated signs of increased intracranial pressure and reported a progressive loss of vision in his right eye. Neuroradiological imaging revealed obstructive hydrocephalus and a lesion inside the third ventricle measuring 1.2 cm in diameter and occluding the interventricular foramen.
Intervention: The cyst was successfully removed via a transcallosal-transforaminal approach. Postoperatively, the patient developed bifrontal effusions for some days. Hydrocephalus was diminished, but his vision had only slightly improved.
Conclusion: To our knowledge, this is the first published report of an endodermal cyst occurring in the third ventricle, and represents a further example of the broad spectrum of lesions affecting that location.