目的探讨毛细胞粘液样型星形 细胞瘤(PMA)的影像学表现。方法 对3 例PMA临床、病理和CT、MRI表现回顾分 析，结合文献报道，提高对PMA的影像学 认识。结果 3例PMA均为女性儿童或青少 年，分别位于丘脑、颞叶基底节和视交叉 下丘脑区，1例为囊性，2例为囊实性，均 见出血。CT上表现为等或略低密度。T1WI 为等或略低信号，T2WI为高信号，DWI为 高或低信号，ADC值增高；增强扫描表现 为不均匀明显强化。3例中2例有轻微瘤周 水肿，1例无瘤周水肿。结论 PMA为好发 于儿童及婴幼儿的鞍区、视交叉下丘脑区 域的侵袭性肿瘤，其影像学表现与毛细胞 型星形细胞瘤(PA)略有差异，认识PMA的 影像学特点，有助于PMA的影像诊断。

Objective To analyze CT ang MRI appearance of brain pilomyxoid astrocytomas (PMA). Methods The clinical history, pathological findings, CT and MRI appearance of three PMA patients were analyzed retrospectively. Combining literature review, the imaging feature of PMA were discussed. Results Three PMA were female children or adolescent, and the tumor located in the right thalamus, left temporal lobe/ basal ganglia and hypothalamic/chiasmatic region. One is soild and anothers are cystic, and all with intratumoral hemorrhage. On CT demonstrate as isodensity to mild hypodensity. On T1-Weighted imaging showed iso- to hypointense, and showed heterogeneous hyperintensity on T2WI. On DWI showed isointense or hyperintense and ADC value were increase. On contranst enhancement imaging the tumor showed heterogeneous enhancement or rim enhancement, perilesional edema were seen in two cases, another not. Conclusion Pilomyxoid astrocytoma is a recently identified invasion tumor type characteristically located in the hypothalamic/chiasmatic/third ventricular region and occurring in young children, with little difference imaging findings compared with PA. It is valuable for the diagnosis, therapy and prognosis study to recognition the imaging and pathology feature of PMA.