Extracranial, Extraspinal Meningiomas of the Head and Neck

Abstract

The head and neck is the most frequent location for extraneuraxial meningiomas, be they wholly extracranial or extraspinal or extensions of central nervous system meningiomas. Regardless of anatomic site of origin, nearly all meningiomas arise from meningocytes of arachnoid granulations. Ectopic arachnoid cell clusters have a predilection for areas of dural penetration of cranial nerves, and it is in these areas that most extracranial meningiomas are found. Surgical excision is the mainstay of treatment and must be planned by radiologic studies to determine the extent of the tumor and the presence or absence of a companion central nervous system meningioma. The often locally invasive and aggressive behavior of the meningiomas belies their benign histologic appearance.

Primary intrathoracic meningioma: histopathological, immunohistochemical and ultrastructural study of two cases

“…They have usually been found to arise in cephalic and paravertebral soft tissues and skin but also in the lung and mediastinum [1,2,5,6,7,8,10,11,12,13,15,17,20]. Different theories have been proposed on their pathogenesis and cell of origin [1,7,9,20].…”

“…They have been usually found in the head and neck region (orbit of the eye, temporal bone, nose, paranasal sinuses, mandible and ear) or paraspinal soft tissues [1,2,5,6,10,11,19]. Their etiology is still uncertain, and several mechanisms have been described [1,5,7,9,10,11,19].…”

A parapharyngeal meningioma presenting as a neck mass and multiple cranial nerve palsies

“…In some rare circumstances, it can be found extracranially mainly in the structures adjacent to the cranial cavity. Extracranial meningiomas represent 2% of all meningiomas [1]. The lesion can be primary in nature or extension from an intracranial origin.…”

Meningioma Presenting as a Parapharyngeal Tumor

“…6,8,11,16,20 Since these foramina normally admit the respective cranial and spinal nerves and since their perineuria are direct extensions of the arachnoid membrane, it is not surprising that a meningioma extending along one of these pathways would also become intimately associated with the cotransiting peripheral nerve or nerves. 6 In this case the meningioma had emerged through the jugular foramen, thereby following the course of the 9th-11th cranial nerves into the carotid sheath to involve the parapharyngeal space, copositioning itself with the deep lobe of the ipsilateral parotid gland so as to clinically mimic a primary salivary gland tumor.…”

“…This is a drastic procedure, usually reserved for attempted curative eradication of unequivocally malignant tumors. Although a paper by Larson et al alludes to the potential biologic significance of perineural infiltration, 14 too few cases associated with peripheral nerves, 6,8,11,16,20 let alone those showing perineural infiltration, have been studied in comparison to meningiomas without this feature for any firm conclusions to be drawn. In addition, the generally long duration of symptoms in meningiomas involving cranial nerves appears to speak against biologic aggressiveness, reaching a maximum of 11 years in Nichols' review, with the most common symptom, hoarseness, lasting a maximum of 6 years.…”