Delayed CSF Leak with Encephalocele after Rathke’s Cleft Cyst Fenestration

Background: The standard surgical option for symptomatic Rathke’s cleft cysts involves an endoscopic endonasal approach for cyst fenestration and drainage. In the absence of an intraoperative CSF leak, the dural defect is often not repaired. The reported rates of postoperative CSF leaks range from 0 to 21%, and the majority of patients who developed these leaks presented within 3 months of surgery. There has been only one case of a delayed CSF leak reported in the literature; however, there have been no cases of delayed CSF leak with associated encephalocele through the dural defect after Rathke’s cleft cyst fenestration.

Method: Here, we present a patient who presented with a CSF leak with associated encephalocele 16 months after Rathke’s cleft cyst fenestration.

Case Report: A 28-year-old female initially presented in 2016 with primary amenorrhea. She was noted to have hypothyroidism and Mullerian agenesis, but further workup revealed a 2.4-cm cystic sellar mass on MR imaging ([Fig. 1]). At that time, she was otherwise asymptomatic and was planned to undergo observation with serial imaging. Surveillance imaging 4 years later revealed the mass had grown in size to 4.9 cm, causing a mass effect on the optic chiasm ([Fig. 2]). She ultimately underwent endoscopic endonasal approach to fenestrate and drain the cyst in 2022. Biopsy of the cyst wall was consistent with Rathke’s cleft cyst. Since there was no intraoperative CSF leak, the dural defect to the sphenoid sinus was left open to reduce the likelihood of re-accumulation. She had no evidence of CSF leak at 6 weeks postoperatively but was lost to follow-up. However, 16 months later, she presented with persistent clear rhinorrhea and headache. MR images revealed herniation of basal brain structures through the sellar defect at the prior surgical site ([Fig. 1]). She underwent an expanded endoscopic endonasal approach to reduce the encephalocele and repair the defect with an abdominal fat graft and a nasal septal flap. At her first postoperative visit 3 weeks later, the nasal cavity was debrided without evidence of CSF leak. She continued to do well at her 3-month postoperative visit.

Fig. 1 Sagittal MRI demonstrating 2.6 cm sellar/suprasellar cystic mass in 2016.

Fig. 2 Sagittal MRI demonstrating a Rathke’s cleft cyst that grew to be 4.9 cm in size in February 2022.

Fig. 3 Sagittal MRI demonstrating CSF leak with basal brain herniation through the sella.

Conclusion: A postoperative CSF leak is an uncommon complication of endoscopic transsphenoidal surgery for Rathke’s cleft cysts. Although not previously reported, clinicians must also be aware of the risk of development of an encephalocele through the unrepaired dural defect to better counsel patients preoperatively and advocate for close postoperative surveillance. Abdominal fat and a nasoseptal flap are reasonable repair options in these cases.

 

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No conflict of interest has been declared by the author(s).

Publication History

Article published online:
07 February 2025