AANS Neurosurgeon : Gray Matters

Volume 24, Number 2, 2015

Gray Matters: Colloid Cyst

Vikram C. Prabhu, MD, MS, FAANS

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Bringing Polemic Issues with Inchoate Guidelines into Sharper Focus

Case Description
This 33-year-old, right-handed, Caucasian woman presented with headache and dizziness that started postpartum in 2006. An MRI revealed a colloid cyst without hydrocephalus. Surgical options were discussed but the patient did not want any surgical intervention. Hence, the lesion was followed with serial MRI scans and reported to be stable. A careful perusal of the images suggested a possible 1-2 mm growth over nine years. She reported anxiety and a recent increase in dizziness, blurry vision, floaters and subjective lower-extremity weakness/fatigue. She also reported mild-to-moderate headaches twice a week with occasional stabbing pain over the right temporal area and a pressure sensation in the frontal sinus region. She reported one episode of left forearm tingling a week ago that spontaneously resolved. Her neurological exam was normal (see Figure 1 below). How would you treat this patient? Take the survey to the right.


Figure 1: Coronal T2 (A) weighted images at presentation approximately eight years ago and (B) in November 2014 show an anterior third ventricular lesion with imaging characteristics of a colloid cyst. Normal ventricular size is noted.


The Experts Weigh In

Mark Souweidane, MD, FAANS; New York:
Click here to read this expert’s comments.

Douglas Anderson, MD, FAANS; Maywood, Ill.:
Click here to read this expert’s comments.

Colloid cysts are rare, benign, congenital lesions that are most commonly seen in the anterior third ventricle of adult patients. Hypothesized to arise from ectopic endodermal elements of the paraphysis in the diencephalic roof, they are lined by epithelial and goblet cells that secrete proteinaceous material that possibly contributes to their growth. However, their growth rate is variable, as is their presentation; they may remain indolent for years or be discovered incidentally in asymptomatic patients, or they may present with acute or chronic hydrocephalus with acute neurological deterioration or chronic headaches, respectively.

Symptomatic colloid cysts, whether or not they are associated with hydrocephalus, are surgically removed. Recent literature supports the removal of incidental asymptomatic colloid cysts as well. However, observation with serial imaging studies for incidental, asymptomatic colloid cysts with normal sized ventricles is still a valid option. This patient was followed for eight years with no significant change in her symptomatology; I discussed the option of removing the colloid cyst with her at each visit, but she was concerned about possible side effects of surgery and preferred a conservative approach. At her most recent visit, I was concerned that she reported more headaches and that the cyst had grown, albeit slightly and over many years. She agreed to surgery, and I discussed endoscopic and open craniotomy options with her.

Open Approach
She elected to go with the transcallosal interforniceal approach. This is a technically demanding surgery, and experience plays a role in outcome; I have not done this procedure for almost a decade and hence had her see Douglas Anderson, MD, FAANS, a colleague with significant experience and technical skill with this approach. She underwent a transcallosal interforniceal resection; the callosal incision was 15 mm; microscopic visualization was excellent; removal was en-bloc and complete; and she did very well following surgery.

Endoscopic Removal
With improved instrumentation and optics and increasing operative experience, endoscopic removal of colloid cysts has supplanted the transcallosal interforniceal approach. This is my own preferred approach. I had another patient with an incidental colloid cyst a few months ago who elected to go to New York for her surgery; Mark Souweidane, MD, FAANS, removed it endoscopically, and she did perfectly well.

My own experience: Colloid cysts associated with hydrocephalus are very amenable to endoscopic removal. However, with normal-sized ventricles, it is a technically demanding procedure; the working space is limited; removal is piecemeal; minor bleeding can obscure your field significantly; and I am always concerned about the use of continuous irrigation inducing acute intracranial hypertension in non-compliant ventricles. The choice of surgical approach under these circumstances needs to be carefully considered. I suggest that both the endoscopic and open microsurgical approaches are valuable options, and the final selection should rest on the training and experience of the operating surgeon and the individual patient’s preference.

Prabhu_VikramVikram C. Prabhu, MD, MS, FAANS, is professor and residency program director at Loyola University Medical Center in Maywood, Ill. His practice is focused on neurosurgical oncology and peripheral nerve surgery. He is a member of the AANS Neurosurgeon Editorial Board and has no conflict of interest to disclose. He may be reached at

Suggested Reading

1. Margetis K, Christos PJ, Souweidane M. Endoscopic resection of incidental colloid cysts. J Neurosurg. 2014 Jun;120(6):1259-67.

2. Sheikh AB, Mendelson ZS, Liu JK. Endoscopic versus microsurgical resection of colloid cysts: A Systematic Review and Meta-Analysis of 1278 Patients. World Neurosurg. 2014 Dec;82(6):1187-1197.

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