A wide variety of rare tumors can occur in childhood and adolescence. Tumors can be rare in any age group; common tumors of adults can appear in childhood and adolescence, and many rare tumors and tumor-like lesions show a predilection for younger age groups. Comparatively frequent tumors can present with rare histologic features or can occur in rare atypical locations, and, finally, seemingly common but, in fact, rare tumors have to be distinguished from truly common but rarely recognized tumors. Thus, the spectrum of rare tumors is broad, reflecting the fluent reality of life.