Round cell tumour

Round cell tumour encompasses a wide variety of undifferentiated primitive neoplasm which have in common the ability, with varying frequency, to present as a nondescript proliferation of round cells with high nuclear cytoplasmic and hyperchromatic nuclei by light microscopy. The neoplastic elements include undifferentiated, uniform, small round to oval closely packed cells with a solitary hyperchromatic nucleus and a high nuclear cytoplasmic ratio. The nucleoli may or may not be prominent. These round cells tumors have several histological pattern, immunohistochemical & electron microscopic features that can help in differential diagnosis