This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Head & Neck, Subject name: Pathology
Cambium layer is seen in: 
Select and explain. 
A. Embryonal rhabdomyosarcoma, B. Pleomorphic rhabdomyosarcoma, C. Alveolar rhabdomyosarcoma, D. Undifferentiated rhabdomyosarcoma
A: Embryonal rhabdomyosarcoma
Answer: A: Embryonal rhabdomyosarcoma 
Explanation: Ans. (a) Embryonal rhabdomyosarcoma(Ref: Robbins 9th/pg 1253)In Sarcoma botryoides, a variant of embryonal rhabdomyosarcoma, histology shows a cambium layer where the tumors about the mucosa of an organ, they form a submucosal zone of hypercellularity.