Case of the Month - January

Symptoms

Symptoms include unwell and right cervical lymphadenopathy.

Diagnosis

Retropharyngeal space abscess.

Investigation

Left Image: Axial CECT demonstrating a right-sided focal round unilateral cystic mass (suppurative node) and retropharyngeal rim enhancing abscess situated between the pharyngeal mucosal space anteriorly, and the prevertebral muscles posteriorly.

Right Image: Sagittal CECT of the same patient reveals the abscess mildly displacing the pharynx and oesophagus anteriorly and extending inferiorly towards the superior mediastinum.

Discussion

Retropharngeal space abscess typically occurs when head and neck infection (tonsillitis, pharyngitis) seeds an retropharyngeal space (RPS) lymph node --> reactive node --> suppurative node (intranodal abscess).
Nodal rupture --> RPS abcess.

The most common organisms are Staphylococcus aureus, Haemophilus, Streptococcus.

Ventral spread of discitis / osteomyelitis is a more frequent cause of RPS abscess in adults.

Complications include:

• airway compromise
• inferior spread via danger space to mediastinum, resulting in mediastinitis.
• Carotid space involvement leading to Jugular vein thrombosis, ICA narrowing, rarely ICA pseudoaneurysm/rupture.
• Perivertebral space involvement may lead to epidural abscess.

CT is the radiological investigation of choice, allowing differentiation between suppurative RPS node with oedema, and RPS abscess.

Prognosis is generally excellent if early diagnosis with aggressive management instituted.