急性淋巴细胞白血病/淋巴瘤（ALL）是一种主要累及骨髓或淋巴器官的全身性疾病。 ALL 的结外表现并不常见，并且 ALL 表现为硬脑膜肿块的情况极为罕见。在此，我们介绍一例原发性硬脑膜 B 细胞 ALL 病例，该病例在术前根据临床放射学诊断为脑膜瘤。一名 27 岁女性患者出现持续一个月的左半侧头痛，伴有双眼视力进行性丧失和行为改变。对比增强磁共振成像 (CE-MRI) 提示硬脑膜肿块伴硬脑膜尾征。切除标本的组织病理学检查显示 B 细胞 ALL。进一步的系统检查未发现任何外周血、骨髓或淋巴结受累。据我们所知，迄今为止文献中仅报道了两例原发性硬脑膜 ALL 病例。本报告强调了髓外前体淋巴肿瘤的诊断困难。

Acute lymphoblastic leukaemia/lymphoma (ALL) is a systemic disease which primarily involves bone marrow or lymphoid organs. Extranodal presentation of ALL is uncommon, and ALL presenting as a dural mass is exceedingly rare. Here we present a case of primary dural B-cell ALL which was preoperatively diagnosed as meningioma on clinico-radiological grounds. A 27-year-old female patient presented with left hemicranial headache for one month's duration along with progressive vision loss of in both eye and altered behaviour. Contrast enhanced magnetic resonance imaging (CE-MRI) suggest dural based mass with dural tail sign. Histopathological examination of the resected specimen revealed B-cell ALL. Further systemic investigations didn't suggest any peripheral blood, bone marrow or lymph node involvement. To the best of our knowledge, only two cases of primary dural ALL have been reported in the literature so far. This report highlights the diagnostic difficulty in extramedullary precursor lymphoid neoplasm.