Round cell tumours overwhelming majority of malignancies seen in children. These tumors are composed histologically of small round cells with scanty basophilic cytoplasm and include a variety of tumors such as malignant lymphoma, Ewing‘s sarcoma, neuroblastoma, rhabdomyosarcoma, Wilms‘ tumor,retinoblastoma and malignant small round cell tumor of thoracopulmonary region. The differential diagnosis of these tumors may be difficult at light microscopic level, but is helped considerably by electron microscopic evaluation.‘Fine–needle aspiration biopsy (FNAB) is now being used with increasing frequency for the diagnosis of various benign and malignant neoplasms from a variety of location However, this technique has not been applied extensively in the diagnosis of round cell tumors in children because of difficulty in making a precise diagnosis at the light microscopic level