Finger-like protrusions (FPs) extending into the hypothalamus in adamantinomatous craniopharyngiomas (ACPs) pose surgical challenges and their link to tumor recurrence and patient prognosis following gross total resection (GTR) is unclear. This study aims to determine the association between FPs, tumor recurrence, and prognosis after GTR, while identifying predictors for the presence of FPs. A total of 149 ACP patients undergoing GTR at our institution between January 2015 and December 2023 were retrospectively analyzed and were categorized into FP and non-FP groups based on the histology of the interface between ACP and the hypothalamus. Various parameters were compared, and logistic regression analyses were conducted to identify predictors for the presence of FPs in ACPs. The FP group (n = 50) had higher rates of meningitis (p = 0.020), postoperative hydrocephalus (p = 0.014), pneumonia (p <
0.001), perioperative mortality (p = 0.036), radiological hypothalamic injury (p <
0.001), and hypothalamic dysfunction (p <
0.001) during follow-up. They also showed inferior recurrence-free survival (p = 0.012) and overall survival (p = 0.023). Predictors for FPs in ACPs included solid tumor (OR 5.28, 95% CI 1.81-15.40
p = 0.002) and preoperative MRI without an upward eagle sign (OR 27.65, 95% CI 8.93-85.65
p <
0.001). FPs in ACPs pose challenges for achieving safe radical tumor resection and are linked to higher recurrence rates and unfavorable patient outcomes after GTR. Solid tumor consistency and preoperative MRI without an upward eagle sign could predict the presence of FPs in ACPs involving the hypothalamus. For ACPs demonstrating these characteristics, a more conservative resection should be considered. Additionally, rigorous postoperative monitoring for tumor recurrence is essential for ACPs with FPs, even after GTR.