Patel Shivam H, McKnight Kelly N, Vyas Parth A
School of Medicine and Health Sciences, University of North Dakota, Grand Forks, USA.
Orthopaedic Surgery, Sanford Health, Fargo, USA.
Cureus. 2022 Dec 16;14(12):e32590. doi: 10.7759/cureus.32590. eCollection 2022 Dec.
Meningiomas are the most common central nervous system tumor. They are typically benign neoplasms but may produce neurological symptoms due to mass effect. Meningiomas may also extend to extradural locations; however, these account for only a small percentage of all meningiomas. Most extradural meningiomas arise in intraosseous locations, usually within the cranial bones or vertebrae. However, this is a rare case of extradural extension of an asymptomatic intracranial meningioma to the proximal humerus in the absence of any musculoskeletal symptoms. To the best of our knowledge, this presentation of an extradural intraosseous meningioma has not previously been reported in the literature. We present a case of an incidental intraosseous meningioma in a 66-year-old man. This patient was initially being screened for metastasis of stage IA1 adenocarcinoma of the lung, and a positron emission tomography (PET) scan revealed a focus of activity in the proximal diaphysis of the right humerus suspicious for malignancy. The upper extremity magnetic resonance imaging (MRI) demonstrated an indeterminate lesion. Curettage of the humeral lesion revealed an intraosseous psammomatous meningioma without evidence of metastatic lung carcinoma. Our case report aims to illustrate the importance of considering alternative metastatic sources, such as intracranial meningioma, during the investigation of an indeterminate bony lesion. This is the first case to illustrate asymptomatic intraosseous meningioma in an appendicular skeletal location, highlighting the need for thorough source investigation.
脑膜瘤是最常见的中枢神经系统肿瘤。它们通常是良性肿瘤，但由于占位效应可能会产生神经症状。脑膜瘤也可能延伸至硬膜外部位；然而，这些仅占所有脑膜瘤的一小部分。大多数硬膜外脑膜瘤起源于骨内位置，通常在颅骨或椎骨内。然而，这是一例罕见的无症状颅内脑膜瘤向近端肱骨硬膜外延伸且无任何肌肉骨骼症状的病例。据我们所知，这种硬膜外骨内脑膜瘤的表现此前在文献中尚未有报道。我们报告一例66岁男性偶然发现的骨内脑膜瘤病例。该患者最初是为筛查IA1期肺腺癌转移情况而进行检查，正电子发射断层扫描（PET）显示右肱骨近端骨干有一个可疑为恶性的活性灶。上肢磁共振成像（MRI）显示为一个不确定的病变。对肱骨病变进行刮除术，结果显示为骨内砂粒体性脑膜瘤，未发现肺癌转移证据。我们的病例报告旨在说明在调查不确定的骨病变时考虑替代转移来源（如颅内脑膜瘤）的重要性。这是首例说明在附属骨骼部位出现无症状骨内脑膜瘤的病例，凸显了进行全面来源调查的必要性。
