Pott's puffy tumour: the usefulness of MRI in complicated sinusitis

Abstract

The sinuses are common sites of infection in children, and if clinical presentation is delayed, there is a high risk of complications including intracranial spread. We present a case of a 5-year-old boy who presented with non-specific symptoms of sinusitis. He went on to develop osteomyelitis of the frontal bone and a subperiosteal abscess known as Pott's puffy tumour. Whilst computed tomography provides an excellent initial imaging, this case report emphasizes the advantages of magnetic resonance imaging, especially when there is extensive involvement of the sinuses with an absence of ionizing radiation. Prompt surgical treatment is imperative as there is a potential for significant morbidity if not quickly diagnosed and treated.

Figure 1:

Post-contrast axial CT (A) shows opacified paranasal sinuses keeping with sinusitis. Right orbital subperiosteal abscess (arrowhead) and scalp subperiosteal abscess (arrow) consistent with Pott's puffy tumour seen on CT (B and C).

Figure 2:

Post-drainage of right maxillary sinus and right orbital subperiosteal abscess MRI was performed. MRI shows abnormal signals (arrow) from the anterior frontal bone suggesting osteomyelitis (A). Post-contrast MRI demonstrates the scalp Pott's puffy tumour (circle) with surrounding scalp enhancement. MRI (B) also shows reactive dural enhancement and an epidural abscess that is better seen (arrowhead) on sagittal sequence (C) compressing the superior sagittal sinus (arrow) which is not thrombosed. Diffusion images (D–F) confirm pus in left maxillary sinus (D), scalp subperiosteal abscess (E) and intracranial extra-axial (F) epidural abscess (arrows).