A Recurrent Suprapituitary Ependymal Cyst Managed by Endoscopy-Assisted Transsphenoidal Surgery in a Canine: A Case Report

Abstract

A 9-years-old spayed female mixed-breed dog was referred for the evaluation of intermittent head tremors, obtundation, long-standing blindness, and a tendency to seek confined spaces. The dog lost its vision 6 months before the current presentation. A menace response was absent on ophthalmological examination. Neurological examination did not show any abnormalities. A cyst measuring 16 × 18 × 14 mm was observed above the pituitary gland on magnetic resonance imaging. It extended toward the frontal area and compressed the optic chiasm and hypothalamic regions. A minimum preoperative database, including the findings of other required blood tests, was prepared. No abnormal laboratory findings were observed. Endoscopy-assisted transsphenoidal hypophysectomy was performed to remove the pituitary gland, drain the cyst, and partially excise the cyst wall. Normal pituitary gland tissue was observed on histopathology, and the mass was found to have a neuroendocrine or ependymal origin on cytology. Strict post-operative laboratory tests were performed at 1-h intervals for 24 h. An empty sella turcica region, and a collapsed and empty cyst wall was observed on follow-up magnetic resonance imaging. After 3 days of observation, the dog was discharged with a prescription of substitution therapy. However, the dog presented with the same signs and symptoms 73 days after the surgery. Cyst recurrence was apparent on magnetic resonance imaging. The owner requested euthanasia, and an ependymal cyst was observed on necropsy. To the best of our knowledge, we present the first case of an intra- and suprasellar ependymal cyst, and its surgical management in a canine. The findings from this case suggest that endoscopic transsphenoidal drainage and hypophysectomy could be a good surgical approach in cases where involvement of the pituitary gland is confirmed or strongly suspected on the basis of cytological and imaging findings.

Transorbital postcaruncular endoscopic surgery as an alternative to orbital exploratory surgery: A cadaveric study and case report in a dog with an orbital sarcoma

“…An endoscope‐assisted approach provides several advantages to the surgeon, such as increased light intensity, magnification at the operating site, and excellent visualization and access to poorly accessible sites 12 . Endoscope‐assisted approaches are gaining traction in veterinary medicine and are more frequently being used in novel locations to improve outcome 19 . Complications from the use of the orbital endoscopy in people are extremely rare 12 .…”

Symptomatic lateral ventricular cystic lesion in a young cat

“…22 The osmotic gradient between the intra-and extracystic medium, and fluid hypersecretion by the lining cells of the cyst wall, were suggested. 23 Finally, no description of feline ependymal cysts has been published previously and only two cases are reported in dogs, 25,26 including one cerebellar, in the fourth ventricle, 25 and one suprapituitary in the third ventricle for the more recent case. 26 In humans, they are rare and often located deep within brain parenchyma, in the central white matter, or are juxtaventricular.…”

“…23 Finally, no description of feline ependymal cysts has been published previously and only two cases are reported in dogs, 25,26 including one cerebellar, in the fourth ventricle, 25 and one suprapituitary in the third ventricle for the more recent case. 26 In humans, they are rare and often located deep within brain parenchyma, in the central white matter, or are juxtaventricular. 8 The origin of these cysts is also controversial, but an embryological abnormality is suspected subsequent to sequestration of developing neuroectoderm.…”

“…In veterinary medicine, two feline quadrigeminal cysts have been successfully treated with cystoperitoneal shunt. 4,5 In dogs, surgical resection has been described for intracranial cystic lesions, 14,17,22,[25][26][27] but a cystoperitoneal shunt also appears to be an effective treatment method. 28 Among canine cases of intracranial cystic lesions, two cases of choroid plexus cysts have been surgically treated, with no recurrence documented after follow-ups of 3 and 18 months, follow-up.…”

“…15,22 However, local recurrence of ependymal or neuroendodermal cysts were reported after incomplete surgical excision. 15,26 Therapeutic decisions must be based on cystic location or accessibility, but permanent procedures should be promoted.…”