Foramen magnum meningioma with excessive calcification and no dura tail sign: A case report.

RATIONALE: Foramen magnum meningiomas are very rare lesions. They frequently originate from the arachnoid cells at the dura matter of the craniocervical junction. Foramen magnum meningiomas are challenging for neurosurgeons because of the complex anatomy of foramen magnum. We present a rare case of FMM with excessive calcification and without the dura tail sign which made the lesion mimic a teratoma.

PATIENTS CONCERNS: A 63 years old woman presented with progressive numbness and hyperesthesia of the shoulders and upper limbs for 2 and half years. She also experienced occasional headaches and dizziness with no nausea, vomiting or fever.

DIAGNOSES: Computed tomography scan, and magnetic resonance imaging revealed a calcified mass at occipital cistern. The lesion did not show the usual "dura tail sign" which made it mimic a teratoma on magnetic resonance imaging. Histopathology established meningioma.

INTERVENTION: The tumor was completely resected via suboccipital approach.

OUTCOMES: Two years follow-up revealed no recurrence of the lesion and no neurological deficits.

LESSONS: We advocate the use of electromyographic and auditory brainstem responses to monitor the inferior cranial nerves because the tumor often adheres to these nerves.