2025 Poster Presentations
P293: INTRA-INFUNDIBULAR EPIDERMOID CYSTS - A RARE AND DISTINCT ENTITY
Chandrima Biswas, MD; Ludovica Pasquini, MD; Guilherme Mansur, MD; Moataz D Abouammo, 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: Epidermoid cyst (EC) located within the pituitary infundibulum is a rare disease with only seven reported cases. They are anatomically and embryologically distinct from suprasellar ECs. Preoperatively, they are usually assumed to be craniopharyngiomas or Rathke’s cleft cyst. However, all these entities have different management strategies and postoperative concerns. In this study, we have described our experience with three cases of intra-infundibular epidermoid cysts (IEC) operated on at our institute and performed a systematic review of literature highlighting its distinguishing features on imaging, treatment nuances and morbidity profile.
Case illustration: A 69-year-old man presented after a subtotal endoscopic endonasal resection of a sellar-suprasellar mass at another institution. A definitive pathological diagnosis could not be achieved following an inadequate tissue sample leading to a presumptive diagnosis of craniopharyngioma. He was referred to our radiation oncology team with worsening visual symptoms and magnetic resonance imaging (MRI) brain suggesting disease recurrence. He underwent repeat resection of the mass through an extended endoscopic endonasal trans-tubercular approach by the senior authors. Immediately opening the sellar dura, flakes of pearly white semisolid material was encountered. The dural incision was extended, and an incision was made longitudinally along the infundibulum to visualize the cyst. The tumor was progressively dissected from the walls of the hypothalamus until a complete resection was achieved. The histopathology was suggestive of epidermoid cyst. The patient was well for ten months, when a routine surveillance MRI demonstrated reoccurrence of a cystic mass in the suprasellar cistern with avid diffusion restriction. The cyst was evacuated, and histopathological examination did not demonstrate evidence of keratin or epidermal cells. Cytology showed the presence of few inflammatory cells. Postoperatively patient had a mild transient left sided weakness and was continued on steroid and thyroid supplementation.
Results: A total of 10 cases (seven from the literature and three of our own) were analyzed. The median age at diagnosis was 53.5 years and six cases were male. Preoperatively, all patients had visual disturbance, 6 out of 8 patients (8 reports mentioned the hormonal profile) had a deficiency in pituitary hormones with 3 out of 8 having diabetes insipidus (DI). The average tumor size was 1.62 cm3 with 7 predominantly cystic lesions. On T1 weighted MRI most lesions had low or mixed signal intensity while one lesion was bright. Diffusion restriction was noted in 4 out of 5 cases. Adhesion of the cyst wall to the stalk and/or the hypothalamus was a common occurrence resulting in residual wall being left behind in 5 cases. Expanded endoscopic endonasal approach (EEA) was utilized in 9 cases and one case underwent fronto-temporal craniotomy with resection via pretemporal approach. All patients except one required postoperative hormonal supplementation. Postoperative chemical meningitis was demonstrated in two cases and a sterile abscess was noted in another case.
Conclusion: IECs have distinct radiological features, treatment strategies, and postoperative morbidity profiles compared to other cystic lesions in the infundibulum. Thus, it is important to recognize this distinct and rare entity.
