Medullary thyroid carcinoma in a 6-year-old boy with previous Langerhans cell histiocytosis presenting high level of pro-calcitonin - Gerdi Tuli; Jessica Munarin; Francesco Quaglino; Giulia Carbonaro; Veronica Barat; Luisa de Sanctis; Franca Fagioli (Pediatric Endocrinology, Diabetes and Metabolism)