Forbes Jonathan A, Mobley Bret C, O'Lynnger Thomas M, Cooper Calvin M, Ghiassi Mahan, Hanif Rimal, Pearson Matthew M
Department of Neurosurgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
J Neurosurg Pediatr. 2011 Jul;8(1):90-6. doi: 10.3171/2011.4.PEDS1115.
Pediatric cerebellar astrocytomas with pilomyxoid features include classic pilomyxoid astrocytomas (PMAs) and intermediate pilomyxoid tumors (IPTs). Since the original description of PMA in 1999, most reports in the literature have described PMAs arising from the hypothalamic/chiasmatic region. To the authors' knowledge, PMAs arising from the posterior fossa have not been discussed in the neurosurgical literature. Intermediate pilomyxoid tumors, or tumors with pathological features of both pilocytic astrocytoma (PA) and PMA, have only recently been described. In this article, the authors present 2 cases that fall within the spectrum of pediatric cerebellar PMA-including a classic PMA and an intermediate pilomyxoid tumor. The authors compare the radiological presentation, surgical results, and postoperative course to findings in a cohort of 15 patients with cerebellar PAs.
Between 2003 and 2010, 2 patients with pilomyxoid-spectrum astrocytomas underwent treatment at Vanderbilt Children's Hospital. One was a 22-month-old girl who presented with progressive gait disturbance and falls. The other was a 4-year-old girl who presented with ataxia and generalized weakness. In a retrospective review of pediatric cerebellar neoplasms resected by the senior author during this period, these tumors comprised 4% of cerebellar neoplasms and approximately 10% of cerebellar glial neoplasms.
Both patients were treated with midline suboccipital craniotomy for resection. In both cases, tumor invasion anteriorly into the brainstem prevented gross-total resection. the patient in Case 1 was placed on chemotherapy following pathological diagnosis and later developed definitive evidence of leptomeningeal dissemination (LD) 3 years after the operation. The patient in Case 2 was placed on chemotherapy after exhibiting progressive evidence of local recurrence (findings were negative for LD) 12 months following resection.
Pediatric patients with cerebellar pilomyxoid-spectrum astrocytomas appear to suffer higher rates of local recurrence and LD than pediatric patients with cerebellar PAs.
具有毛细胞黏液样特征的小儿小脑星形细胞瘤包括经典毛细胞黏液样星形细胞瘤（PMA）和中间型毛细胞黏液样肿瘤（IPT）。自1999年首次描述PMA以来，文献中的大多数报道描述的是起源于下丘脑/视交叉区域的PMA。据作者所知，神经外科文献中尚未讨论起源于后颅窝的PMA。中间型毛细胞黏液样肿瘤，即具有毛细胞型星形细胞瘤（PA）和PMA两种病理特征的肿瘤，直到最近才被描述。在本文中，作者介绍了2例属于小儿小脑PMA范畴的病例——包括1例经典PMA和1例中间型毛细胞黏液样肿瘤。作者将这2例病例的影像学表现、手术结果及术后病程与15例小脑PA患者的研究结果进行了比较。
2003年至2010年间，范德比尔特儿童医院收治了2例具有毛细胞黏液样特征的星形细胞瘤患者。1例为22个月大的女童，表现为进行性步态障碍和跌倒。另1例为4岁女童，表现为共济失调和全身无力。在对资深作者在此期间切除的小儿小脑肿瘤进行回顾性研究时发现，这些肿瘤占小脑肿瘤的4%，约占小脑神经胶质肿瘤的10%。
2例患者均接受了枕下中线开颅切除术。2例病例中，肿瘤向前侵犯脑干均导致无法全切。病例1的患者在病理诊断后接受了化疗，术后3年出现明确的软脑膜播散（LD）证据。病例2的患者在切除术后12个月出现局部复发进展证据（LD检查结果为阴性）后接受了化疗。
与小儿小脑PA患者相比，小儿小脑毛细胞黏液样特征星形细胞瘤患者似乎有更高的局部复发率和LD发生率。
