Meningioma with cervical extension masquerading as cervical paraganglioma

Abstract

Carotid body paragangliomas are the most common extra-adrenal paraganglioma and arise from the carotid body at the bifurcation of the internal carotid artery and external carotid artery. The differential diagnosis for a cervical mass in this region includes vagal paraganglioma, jugulotympanic paraganglioma, middle ear adenoma, meningioma, schwannoma, and thyroid malignancy. This case describes an otherwise healthy 23 year old female who presented with right neck pain, swelling, difficulty swallowing, and intermittent left arm weakness and numbness. Multiple imaging studies demonstrated an 8 cm enhancing soft tissue mass encasing the internal carotid artery and extending from the carotid bifurcation to the skull base, with intracranial involvement of the posterior fossa. Due to the tumor location as well as involvement of the carotid artery, a multi-disciplinary team consisting of oral and maxillofacial surgery and vascular surgery performed resection of the tumor utilizing exposure of the skull base with a double mandibular osteotomy technique. Though the presumptive diagnosis of the tumor was paraganglioma, the pathology report revealed the tumor was a psammomatous meningioma.Extracranial meningioma is a rare disease process. In this case there were several findings atypical for carotid body tumor or paraganglioma. Despite the enhancing features of the tumor on CT scan there was no splaying of the internal and external carotid arteries that would be typical for a carotid body tumor. Moreover, though the majority of the tumor mass was extracranial, there was intracranial extension which is rare for cervical paragangliomas. With imaging showing tumor encasement of the carotid artery, preoperative planning was assisted by a ‘halo sign’ that demonstrated a tissue plane between the mass and the internal carotid artery (Figure). This case demonstrates the importance of establishing a wide differential diagnosis for a cervical mass and highlights that an extracranial meningioma can mimic a cervical paraganglioma. The creation of a multidisciplinary team proved essential for effective access to tumor removal and patient safety.