Parapharyngeal space meningioma

Parapharyngeal space (PPS) meningiomas are rare extracranial tumors that can mimic more common PPS lesions. We report a case of a 23-year-old female who presented with a painless, progressive neck swelling and intraoral bulge. Imaging revealed a well-defined, homogeneously enhancing mass in the left PPS with encasement of the internal carotid artery, compression of the internal jugular vein, and widening of the hypoglossal canal with adjacent dural enhancement. Core biopsy showed meningothelial whorls and psammoma bodies. Immunohistochemistry was positive for EMA and progesterone receptor, negative for S-100, with a low MIB-1 index, consistent with a WHO Grade I meningioma expressing somatostatin receptors. The tumor was deemed unresectable due to complete vascular encasement, and the patient was treated with peptide receptor radionuclide therapy (PRRT), resulting in tumor regression. This case underscores the importance of including meningioma in the differential diagnosis of PPS masses and highlights PRRT as a viable option in select unresectable, receptor-positive cases.