2025 Poster Presentations
P051: PURELY TRANSORBITAL ENDOSCOPIC RESECTION OF GASTROINTESTINAL STROMAL TUMOR METASTASIS EXTENDING FROM TEMPORAL FOSSA TO THE MASTICATOR SPACE
Hazan Basak, MD, PhD; Arjin Oksuz, MD; Eyup Bayatli, MD; Ihsan Dogan; Suha Beton; Ankara University
Introduction: Gastrointestinal stromal tumors (GISTs) are the most common malignant subepithelial lesions (SELs) of the gastrointestinal tract in the daily clinical setting. To the best of our knowledge, this is the first case purely transorbital endoscopic removal of a GIST metastasis from orbit and masticator space.
Case: A 58-year-old woman presented with a history of right eyelid swelling and orbital pain. She had a history of a prior stomach gastrointestinal stromal tumor (GIST) with a large metastasis to the frontotemporal lobe; brain tumor removed but intraorbital and masticator part was left untouched for 18 months. On examination eye motility restrictions to lateral and superior with no relative afferent pupillary reflex and 4 mm of right-side proptosis were detected. On CT and MRI there is a heterogeneous contrasting solid mass lesion in size of 55x40 mm in the temporal bone squamous part on the right sphenoid greater wing, which reaches the masticator space, destroys the pterygoid plates that cause pressure from the posterolateral to the orbit and causes proptosis on the right. The right bulbus oculi is anterior to the interzygomatic line. It was pushed medially by the right lateral rectus muscle mass. The squamous portion of the right temporal bone and the right orbital lateral wall are destroyed. Total tumor resection were achieved with purely Transorbital endoscopic approach. Patient discharged 1 day after surgery. In postoperative 6 months eye movements are completely normal no sign of recurrence were detected by oncological follow ups.
Conclusion: In suitable cases transorbital approaches can be use to remove tumors extending from skull base to masticator space in minimally invasive way.