Unverified postoperative imaging clouds gross-total resection claims in pediatric dermoids

A letter published in the Egyptian Journal of Neurosurgery on 20 October 2026 raises a methodological challenge to a recently published systematic review of pediatric posterior fossa dermoid cysts. Author Turan Yildiz, writing with Ercan Yilmaz, argues that the review’s central conclusion favoring gross-total resection rests on an outcome measure that was never consistently defined or objectively verified across the studies it pooled.

The review in question, by Ayamba and colleagues and published on 18 August 2026, synthesized 96 cases of pediatric posterior fossa dermoid cysts and concluded that gross-total resection, abbreviated GTR, is the preferred approach for symptomatic lesions. The letter writers acknowledge that this recommendation carries direct surgical weight, because complete removal of the cyst capsule can endanger the brainstem, cranial nerves, or nearby blood vessels in this delicate region.

The core concern centers on one illustrative operation described in the review. That operation was classified as a gross-total resection, yet the contrast-enhanced CT scan performed on the second day after surgery was described as showing two small residual cystic enhancing lesions near the superior vermis. The original authors acknowledged that follow-up MRI was unavailable for this patient, but the letter argues they never reconciled those immediate CT findings with the GTR label.

Yildiz and Yilmaz lay out the interpretive problem in technical terms. Histopathology can establish what the lesion was, but it cannot establish that no lesion remained after surgery. The immediate postoperative foci could represent residual dermoid tissue, ordinary postoperative change, or something indeterminate. Without later imaging to resolve the question, the letter contends, those findings must remain unresolved, and the validity of the reported extent-of-resection outcome is directly affected.

The letter stresses that this is not merely a complaint about missing long-term surveillance data. It is a concern about how the resection outcome itself was measured. The review’s methods, according to the letter, do not define gross-total resection or subtotal resection, and they do not specify whether those categories were assigned based on the surgeon’s operative impression, early postoperative imaging, or later surveillance scans.

This definitional gap matters because the pooled case reports span different imaging eras and different modalities. An operation judged complete by visual inspection may still leave radiographically detectable residual disease, while early postoperative enhancement may not represent persistent cyst tissue at all. The letter also notes that pediatric reports have described surgeons intentionally leaving adherent capsule in place to protect vital structures, with any residual disease then followed radiologically over time.

The practical consequence, as the letter frames it, involves how the review’s headline figure is used. The review relies on a high proportion of gross-total resections to support complete excision as the preferred strategy. If GTR means surgeon-assessed removal in some reports and imaging-confirmed clearance in others, the pooled proportion may overstate how often anatomical clearance was actually verified. Readers could then misinterpret that figure as justification for pursuing radical capsule dissection, precisely the maneuver that risks neurological injury.

The letter points out that the appropriate surgical decision should balance the risk of residual growth or recurrence against the risk of neurological damage, and it observes that recurrence after apparently complete resection has been reported in the broader intracranial dermoid literature.

As a remedy, the authors propose what a clinically interpretable synthesis would require: separating operative assessment from radiographic extent of resection, stating the postoperative imaging modality and its timing for each case, and linking each resection category to neurological morbidity, recurrence, and reoperation rates.

The letter closes with a restrained but pointed conclusion. Until extent-of-resection criteria are clarified, the pooled gross-total resection proportion should be treated as descriptive only, and it cannot establish complete excision as the preferred clinical endpoint for pediatric posterior fossa dermoid cysts.

Subject of Research: Methodological critique of how gross-total resection is defined and verified in systematic review evidence on pediatric posterior fossa dermoid cysts.

Article Title: Unreconciled postoperative imaging limits interpretation of gross-total resection in pediatric posterior fossa dermoids

Article References: Yildiz, T., & Yilmaz, E. (2026). Unreconciled postoperative imaging limits interpretation of gross-total resection in pediatric posterior fossa dermoids. Egyptian Journal of Neurosurgery, 41(1), Article 177. https://doi.org/10.1186/s41984-026-00687-8

Image Credits: AI Generated

DOI: 10.1186/s41984-026-00687-8

Keywords: pediatric neurosurgery, posterior fossa, dermoid cyst, gross-total resection, postoperative imaging, systematic review, extent of resection, brainstem, surgical outcomes, letter to the editor, Unreconciled, postoperative