IgG4-related disease (IgG4-RD) is a multisystem fibroinflammatory condition; this can be a challenging diagnosis that requires clinico-pathologic correlation. We report a young woman, presenting with cranial nerve palsy. The work-up revealed pachymeningitis, cerebral venous thrombosis (CVT), and a destructive lesion in the mastoid. We diagnosed IgG4-RD through mastoidectomy. Thus, a biopsy of asymptomatic, infrequently affected organs, like the mastoid, can meet all histopathological criteria. In neuro-meningeal presentations, CVT may be secondary to the local inflammatory environment of pachymeningitis. Since our patient had a deep vein thrombosis one year prior, we discuss a possible higher risk of thrombosis in IgG4-RD patients.

IgG4 相关疾病 (IgG4-RD) 是一种多系统纤维炎症性疾病；这可能是一个具有挑战性的诊断，需要临床病理学相关性。我们报告了一名患有颅神经麻痹的年轻女性。检查显示硬脑膜炎、脑静脉血栓形成 (CVT) 和乳突中的破坏性病变。我们通过乳突切除术诊断出 IgG4-RD。因此，对无症状、不常受累的器官（如乳突）进行活检可以满足所有组织病理学标准。在神经脑膜表现中，CVT 可能继发于硬脑膜炎的局部炎症环境。由于我们的患者一年前有深静脉血栓形成，我们讨论了 IgG4-RD 患者血栓形成的可能更高风险。