<prompt> About Langerhans cell histiocytosis, true are all except:Peak incidence less than 3 years of ageRadiosensitiveDiffuse form is known as Letterer-Siwe-diseaseGonadal involvement occurs  <response>: d. Gonadal involvement occursRef: Nelsons 20e p 2484-2489; Ghai 8e p 620-623a. Peak incidence less than 3 years of age: True; More common and more severe in younger childrenb. Radiosensitive: True, as Bone lesions and Pituitary lesions, causing DI, respond well to radiotherapyc. Diffuse form is known as Letterer-Siwe disease: Trued. Gonadal involvement occurs: FALSE; Gonadal involvement is usually not seen in LCH. 