All of the following are examples of a round cell tumor, except -
osteosarcoma is not a round cell tumour but all others are. the lace-like pattern of neoplastic bone produced by anaplastic tumour cells is seen here. Source robbins basic pathology 7tyh edition page no.1295. chapter bones, joints and soft tissue tumours.
Neuroblastoma
Ewing's sarcoma
Non Hodgkin's Lymphoma
Osteosarcoma
Pediatrics, environment and nutrition