This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S., Subject name: Pediatrics
About Langerhans cell histiocytosis, true are all except: 
Select and explain. 
A. Peak incidence less than 3 years of age, B. Radiosensitive, C. Diffuse form is known as Letterer-Siwe-disease, D. Gonadal involvement occurs
D: Gonadal involvement occurs
Answer: D: Gonadal involvement occurs 
Explanation: d. Gonadal involvement occurs(Ref: Nelson's 20/e p 2484-2489; Ghai 8/e p 620-623)a. 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.