Collision lesions of the sella: co-existence of craniopharyngioma with gonadotroph adenoma and of Rathke's cleft cyst with corticotroph adenoma. - Karavitaki, N; Scheithauer, B; Watt, J; Ansorge, O; Moschopoulos, M; Llaguno, A; Wass, J (Pituitary, 2008)