Department of Medicine, Medical College, 88 College Street, Kolkata 700073, West Bengal, India.
Singapore Med J. 2011 Jun;52(6):e138-40.
Primitive neuroectodermal tumours (PNETs) are rare tumours that originate from primitive neural crest cells. They are usually found in children below ten years of age. Peripheral PNETs (pPNETs) occur in soft tissues of the body, but have the same genetic changes as Ewing's sarcoma of the bone (now called soft tissue Ewing's sarcoma). They commonly present in the thoracopulmonary region, abdomen, pelvis and the extremities. The head and neck regions may also be involved. Our case demonstrates a PNET in the peripheral tissue arising from the left orbital floor and spreading locally to involve the left maxillofacial region, cheek and gum. The incidence of pPNETs is likely to be under-reported in the literature. Recent diagnostic advances, including cytogenetic and immunohistochemical analysis, have allowed these tumours to be distinguished from other small, poorly differentiated round cell tumours such as rhabdomyosarcoma, lymphoma and poorly differentiated synovial sarcoma.
原始神经外胚层肿瘤（PNETs）是一种罕见的肿瘤，起源于原始神经嵴细胞。它们通常发生在十岁以下的儿童中。外周性原始神经外胚层肿瘤（pPNETs）发生在身体的软组织中，但具有与骨尤文肉瘤（现在称为软组织尤文肉瘤）相同的遗传变化。它们常见于胸肺区域、腹部、骨盆和四肢。头部和颈部也可能受到影响。我们的病例展示了一个起源于左眶底并局部扩散至左颌面区域、脸颊和牙龈的外周组织中的 PNET。pPNET 在文献中的报告发病率可能较低。最近的诊断进展，包括细胞遗传学和免疫组织化学分析，使得这些肿瘤能够与其他小的、低分化的圆形细胞肿瘤区分开来，如横纹肌肉瘤、淋巴瘤和低分化滑膜肉瘤。
