Department of Biomedicine, Careggi Hospital, Florence, Italy.
Neuropathology. 2011 Feb;31(1):59-65. doi: 10.1111/j.1440-1789.2010.01113.x.
Rhabdoid meningioma is an uncommon meningioma variant categorized as WHO grade III. The majority of cases occur in adulthood. Herein, we describe a right fronto-temporal rhabdoid meningioma affecting a 3-year-old boy. The lesion measured approximately 4 cm in diameter and incorporated the ipsilateral middle cerebral artery. Sub-total surgical excision of the mass was performed. Histologically, the tumor was mainly composed of globoid plump cells with inclusion-like eosinophilic cytoplasm, peripheral nuclei, prominent nucleoli and occasional intra-nuclear cytoplasmic pseudo-inclusion. The cells appeared in many areas loosely arranged and focally disclosed a papillary architecture. At immunohistochemistry, the tumor cells were EMA, vimentin, HHF35, PgR, INI-1 and p53 positive. The proliferative index (Mib-1) was 15% in the most positive areas. Ultrastructurally, tumoral cells showed an abundant cytoplasm, which was filled with numerous intermediate filaments. Desmosomal junctions were seen. RT-PCR revealed the presence of NF2 gene expression. Molecular study did not indicate alterations of the INI-1 gene, whereas it showed the presence of Pro72Arg in exon 4 at heterozygous state in the TP53 gene. Morphologic features along with immunohistochemical, ultrastructural and molecular results were consistent with the diagnosis of rhabdoid meningioma. The patient was treated with chemotherapy. The lesion remained stable after 33 months of follow-up. Rhabdoid meningiomas rarely occur in children. Owing to its rarity, each new case should be recorded to produce a better clinical, pathological, molecular, prognostic and therapeutic characterization of this lesion.
横纹肌样脑膜瘤是一种罕见的脑膜瘤变体，归类为 WHO 分级 III。大多数病例发生在成年期。在此，我们描述了一例影响 3 岁男孩右侧额颞部横纹肌样脑膜瘤。病变直径约 4 厘米，包含同侧大脑中动脉。对肿块进行了部分切除。组织学上，肿瘤主要由类圆形的胖细胞组成，具有包涵体样嗜酸性细胞质、周围细胞核、显著核仁以及偶尔的核内细胞质假包涵体。这些细胞在许多区域松散排列，局灶性显示出乳头状结构。免疫组织化学染色显示肿瘤细胞表达 EMA、波形蛋白、HHF35、PgR、INI-1 和 p53。增殖指数（Mib-1）在最阳性区域为 15%。超微结构显示，肿瘤细胞具有丰富的细胞质，充满大量中间丝。可见桥粒连接。RT-PCR 显示 NF2 基因表达存在。分子研究未显示 INI-1 基因改变，但在 TP53 基因的外显子 4 中显示存在杂合状态的 Pro72Arg。形态特征、免疫组织化学、超微结构和分子结果与横纹肌样脑膜瘤的诊断一致。患者接受了化疗。在 33 个月的随访中，病变保持稳定。横纹肌样脑膜瘤在儿童中很少见。由于其罕见性，每个新病例都应记录下来，以便更好地对该病变进行临床、病理、分子、预后和治疗特征的描述。
