This study presents a congenital cranial epidermoid cyst with an unprecedented 70-year latency period, elucidating its distinct clinicoradiological features. A 72-year-old woman presented with a slowly enlarging, painless mass in the left frontoparietal region. Imaging revealed skull erosion, restricted diffusion on diffusion-weighted imaging, and hypoperfusion on perfusion-weighted imaging. Cinematic rendering was innovatively applied, providing three-dimensional visualization of intracystic cholesterol deposits and calcifications, which guided precise surgical excision (pathologically confirmed keratin debris). Key takeaways include identification of exceptionally prolonged latency (longest documented), advocating lifelong surveillance
demonstration of superiority of cinematic rendering in resolving complex internal architecture (e.g., solid-cystic interfaces, heterogeneous components), revolutionizing preoperative evaluation protocols
and establishment of a multimodal imaging signature (restricted diffusion + hypoperfusion + computed tomography density heterogeneity) strongly correlated with histologic constituents (keratin/calcifications), enhancing diagnostic specificity. This study provides novel evidence for personalized management and advanced imaging assessment of cranial epidermoid cysts.