2025 Proffered Presentations
S316: APPLICATION OF INTRAOPERATIVE ULTRASOUND IN ENDOSCOPIC ENDONASAL RESECTION OF CRANIOPHARYNGIOMAS.
Chandrima Biswas, MD; Moataz D Abouammo, MD; Ludovica Pasquini, MD; Guilherme Mansur, MD; Mohammad Bilal Alsavaf, MD; Kyle C Wu, MD; Daniel M Prevedello, MD, MBA; Ricardo L Carrau, MD, MBA; The Ohio State University Wexner Medical Center
Introduction: Intraoperative ultrasound (IOUS) is an invaluable tool in neurosurgery. Each intracranial structure and lesion has a unique sonographic characteristics which can aid in identification of pathology and guide resection. Craniopharyngiomas (CPs) are surgically challenging tumors consisting of two separate entities- papillary and adamantinomatous. The prevalence of the BRAF V600E mutation in papillary craniopharyngiomas (PCP) has aligned surgical goals from complete resection to pathological confirmation and implementation of targeted therapy. Gross total resection is still targeted for adamantinomatous craniopharyngioma (ACP). This study aims to identify the characteristic features of each variant of CP based on IOUS characteristics and its utility in assisting endoscopic resection of CPs.
Methods: IOUS images of five (three PCP and two ACP) patients who underwent endoscopic endonasal transsphenoidal resection for CPs were retrospectively evaluated. The following IOUS features were studied- echogenicity, internal heterogeneity, margins, cysts, and calcific shadows. The clinical utility of IOUS was illustrated using two case studies.
Results: PCPs showed more homogenous hyperechogenicity with a characteristic ‘frond-like’ appearance. They may be associated with large cysts and do not show calcific shadows.
ACPs on the other hand had higher internal heterogenic echotexture with hyperechoic calcific foci giving it a ‘salt and pepper’ appearance.
Case illustrations:
Case 1: A 40-year-old gentleman presented with blurred vision, headaches and weight gain. Examination demonstrated bilateral visual field defects. A brain magnetic resonance imaging (MRI) showed a large cystic lesion in suprasellar location with a small nodular enhancing component antero-superiorly; on CT scan there were no calcifications seen. The preoperative impression was of a suprasellar craniopharyngioma, possibly PCP. He underwent resection of the lesion via an endoscopic endonasal trans-tubercular approach. IOUS showed characteristic features of PCP. Cyst was decompressed and majority of the nodular component and cyst wall was resected, leaving behind a portion of the solid component adherent to the pituitary stalk and the optic chiasm. The histopathology was suggestive of a BRAF V600E mutant PCP and the patient is doing well on BRAF/MEK inhibitor treatment.
Case 2: A 48-year-old gentleman presented to us with blurred vision. Examination showed right temporal hemianopia and left inferior altitudinal field defect. A brain MRI showed a predominantly solid lesion in the suprasellar space involving the pituitary stalk and compressing the optic chiasm. No calcification was noted on the CT scan. A preoperative impression of PCP was made, and the patient underwent endoscopic endonasal trans-tubercular resection of the tumor. IOUS showed calcific foci and dural exposure was widened. Intraoperatively, microcalcifications were noted within the tumor and gross total resection was performed preserving the optic apparatus and the pituitary stalk. The histopathology revealed an ACP and the patient had subjective improvement in vision with no endocrinological concerns.
Conclusion: IOUS is a tool that can help aid in the differentiation of the two variants of CPs and can assist in the surgical resection of these lesions making it an important instrument in the endoscopic resection of CPs.
