小圓細胞腫瘤是病理學(xué)概念,，對于組織來源不易判斷的描述,，鏡下腫瘤細胞呈圓形，形態(tài)偏小,，類似于成熟的淋巴細胞,，不同于大圓細胞和梭形細胞，小圓細胞腫瘤見于多種腫瘤,，包括未分化的惡性腫瘤,，預(yù)后較差，常見于青少年,。

（Chronic Lymphocytic Leukemia (CLL) ）

Round cell tumors as the name suggest are comprised round cells with increased nuclear-cytoplasmic ratio. This group of tumor includes entities such as peripheral neuroectodermal tumor, rhabdomyosarcoma, synovial sarcoma, non-Hodgkin's lymphoma, neuroblastoma, hepatoblastoma, Wilms' tumor, and desmoplastic small round cell tumor. These round cells tumors are characterized by typical histological pattern, immunohistochemical, and electron microscopic features that can help in differential diagnosis.

（doi: 10.4103/ijmpo.ijmpo_84_16）Round cell tumors as the name suggest are comprised round cells with increased nuclear-cytoplasmic ratio. This group of tumor includes entities such as peripheral neuroectodermal tumor, rhabdomyosarcoma, synovial sarcoma, non-Hodgkin's lymphoma, neuroblastoma, hepatoblastoma, Wilms' tumor, and desmoplastic small round cell tumor. These round cells tumors are characterized by typical histological pattern, immunohistochemical, and electron microscopic features that can help in differential diagnosis. The present article describes the classification and explains the histopathology and immunohistochemistry of some important round cell tumors.

肉瘤,，Ewing肉瘤為原始的小圓細胞腫瘤，存在FET,，EWSR1,，CD99、NKX2.2陽性,，瘤細胞比淋巴細胞稍大（1-2倍）,，胞質(zhì)稀少。低分化滑膜肉瘤,。

原始神經(jīng)外胚層腫瘤,，Primitive neuroectodermal tumor (PNET)。