Mesoblastic nephroma, also known as congenital mesoblastic nephroma or fetal renal hamartoma, is a rare renal mesenchymal tumor with low malignant potential, occurring most commonly in infants. A case is presented which could be diagnosed on fine needle aspiration cytology complemented with cell‐block immunocytochemistry. The cytopathologists need to be aware of the cytologic and immunocytochemical features of this entity, to accurately diagnose these cases pre‐operatively, so as to avoid unnecessary administration of chemotherapy to these infants.

中文翻译：

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有腹部肿块的婴儿。

中胚层肾瘤，也称为先天性中胚层肾瘤或胎儿肾错构瘤，是一种少见的恶性潜能低的肾间充质肿瘤，最常见于婴儿。介绍了一个病例，可以通过细针抽吸细胞学和细胞块免疫细胞化学进行诊断。细胞病理学家需要了解该实体的细胞学和免疫细胞化学特征，以便在术前准确诊断这些病例，以避免对这些婴儿进行不必要的化疗。