Tumor Spread into the Retropharyngeal Space

Epidemiology

Compared with benign lesions, the retropharyngeal space (RPS) is much more commonly affected by malignancy either by direct invasion or through metastasis to the retropharyngeal nodes. Squamous cell carcinoma of the upper aerodigestive tract may extend into the RPS. However, progressive extension through the prevertebral fascia and into the prevertebral space is unusual.

Clinical Findings

Invasion of the RPS is often overshadowed by symptoms related to the primary tumor in the upper aerodigestive tract. Superior extension with subsequent erosion of the skull base may be associated with deep pain. The pharyngeal mucosa may be displaced anteriorly by the retropharyngeal mass. However, retropharyngeal tumor spread is usually a radiological diagnosis made during tumor mapping.

Pathology

Tumors can spread both inferiorly and superiorly along the RPS. Tumors spreading superiorly are impeded by the attachment of the fascia defining the RPS to the skull base. This may result in extensive erosion of the clivus. It is possible that tumor spread along the RPS originates from metastatic retropharyngeal lymphadenopathy with extracapsular extension.