Chordoma and meningioma arising as a collision tumor in the petroclival region: Case report and literature review

Introduction: The co-existence of two independent brain tumors at the same anatomical site is rare and occurs as a "collision tumor" or "tumor-to-tumor metastasis." In intracranial location, meningioma is the most common neoplasm in such coincidences. Case description: We present a case involving a 31-year-old woman with a complex tumor consisting of chordoma and meningioma in the petroclival region. The patient presented with left facial numbness, ataxia, and left-sided hemiparesis. Computed tomography and magnetic resonance imaging showed a well-demarcated, intradural, extra-axial tumor mass in the petroclival region. After complete total resection, histopathological examination revealed two different parts of the tumor, consisting of chordoma and meningioma. Therefore, additional radiation therapy and adjuvant chemotherapy were given. Discussion: To the best of our knowledge, this is the first description of the simultaneous occurrence of chordoma and meningioma in the same anatomical location. In such a scenario, differential diagnosis of choroid meningioma and chordoma is required. The correct recognition of both components is important for treating this complex tumor, and its separate elements may require independent approaches.