Orbital apex syndrome in a child with a dentigerous cyst: Case report

This is the first published case of a child with a dentigerous cyst involving the pterygopalatine fossa causing an orbital apex syndrome. This case is important for publication so the dentigerous cyst is included clinicians' differentials and given its description of a safe approach to management. An otherwise well 3-year-old girl presented with a 2-day history of right toothache and altered vision, followed by a 1-day history of a painful right eye turning outwards. On examination, there was reduced right eye visual acuity with adduction and vertical gaze deficit, partial lid ptosis and anisocoria. An MRI Brain with contrast demonstrated a lobulated T2/FLAIR hyperintense lesion involving the right pterygopalatine fossa without diffusion restriction or post-contrast enhancement. CT Head/Face + stealth protocol imaging was arranged which was correlated with the MRI to demonstrate the well-defined low-density lesion within the right cavernous sinus extending through the pterygopalatine fossa into the masticator space causing bony expansion without erosion and closely related to a tooth root. Multidisciplinary input was sought from ophthalmology, ENT, neurosurgery, radiology, pathology, paediatric medicine and paediatric oncology teams. The patient underwent an endoscopic excision of the lesion (with sublabial incision/anterior transmaxillary window) under image guidance. Macroscopic removal of the cyst was achieved. Histopathology confirmed a benign cyst and dental follicle tissue concluded to be in keeping with a dentigerous cyst. Postoperative recovery was uneventful. The child was well at the 2-week and 6-week follow up with ophthalmology review noting improved adduction. An MRI is planned for 4 months postoperatively.