[An unusual cervical tumor: meningioma. Apropos of a case of petrous origin. Review of the literature of meningioma presenting as cervical mass].

Primary ectopic meningiomas are uncommon. The authors report a case of a 12-year-old boy with a meningioma presenting as a neck mass. The conclusion of the initial biopsy was chemodectoma, but on surgical resection, the tumour was found to have invaded the petrous bone. Post-operative follow-up was uneventful but magnetic resonance imagery revealed extension to the cerebello-pontine angle, the cavernous sinus, the tentorium and the falx. The authors discuss the main pathogenic hypotheses and the classification of ectopic meningiomas. Based on 62 similar cases reported in the literature, primary ectopic meningiomas are found most often in young subjects, with no female predominance, neurofibromatosis is often observed and angioblastic or malignant features are frequent. These tumours can be divided into 6 localizations (jugulo-carotid space, lymph nodes, parotid gland, thyroid gland, soft paravertebral tissues, skin) and into 3 pathogenic groups (solitary ectopic tumour of the neck, tumour of the neck connected to a cranial or spinal meningioma, metastasis). Meningioma of the jugulo-carotid space with connection to the skull base is the most frequent entity. Solitary ectopic meningiomas of the neck occur in only 1 out of 5 cases. In 2 out of 3 cases, the neck localization involves a connection to a cranial or spinal meningioma. In a few cases the neck mass is a metastasis. These findings suggest that a complete neuroradiological work-up is required. Prognosis depends on the completeness of the surgical resection and the histologic aggressiveness frequently encountered.