Skull-base Invasion of Nasopharyngeal Carcinoma

Abstract

The nasopharynx is situated just below the base of the skull. Nasopharyngeal carcinoma (NPC) has a great tendency to invade adjacent regions fairly early. Due to its deep and hidden anatomical location, the infiltrating ability of the tumour, and the non-specific nature of the symptoms, it is not diagnosed until it reaches an advanced stage. So, NPC may present with base of the skull erosion and/or cranial nerve involvement. Magnetic resonance imaging (MRI) could provide useful information about the position and quality of NPC because of its ideal soft tissue contrast and multi-planar imaging capacity. With gadolinium contrast and fat suppression sequences, it has greater sensitivity over clinical examination in detecting the base of the skull with bone erosion and/or perineural invasion. MRI is the choice of imaging modality for evaluating tumour extension. The aims of this article were to review the imaging studies of skull-base invasion and its impact on tumour staging and prognosis.