Pott's puffy tumour
Pott puffy tumor refers to a non-neoplastic complication of acute sinusitis. It is characterized by a primarily subgaleal collection, subperiosteal abscess, and osteomyelitis. It is usually related to the frontal sinus but is sometimes secondary to mastoid pathology.
Rarer etiologies include trauma, intranasal cocaine, and methamphetamine abuse, and craniotomy.
Although it may affect patients of any age, the incidence is higher in adolescence. It has become unusual since the availability of antibiotics.
The infection erodes through the wall of the obstructed infected sinus to form a subperiosteal abscess. As expected it can be associated with extension intracranially with epidural abscess, subdural empyema, meningitis, and cerebral abscess formation. Dural sinus thrombosis is another possible complication.
The causative agent usually reflects the type of bacterial species responsible for community-acquired chronic sinusitis. The most common infective agents implicated are:
- Streptococcus sp
- Haemophilus influenzae
- Staphylococcus sp
Other reported organisms include
- Pasteurella multocida
CT typically demonstrates an opacified frontal sinus with stranding and swelling of the overlying scalp. Bone algorithm will often demonstrate a defect in the anterior wall of the sinus.
Contrast may demonstrate a focal abscess, and may also allow intracranial complications to be better delineated.
Subtle intracranial involvement is more easily seen at MR imaging. With the injection of gadolinium-based contrast material, one may see early linear enhancement of the dura mater, an extra-axial fluid collection, or an area of cerebritis or focal cerebral abscess formation.
In the scalp, peripheral or rim contrast enhancement may be seen when an organized fluid collection is present.
Treatment and prognosis
Treatment is typically surgical with drainage of the abscess and at least 6 weeks of intravenous antibiotics.
History and etymology
It was first described by Sir Percivall Pott (see Pott disease) in 1760. The characteristic forehead swelling as a result of the subgaleal collection explains the "puffy tumor" part of the name.
Possible differential considerations on imaging grounds include:
- unilateral non-Hodgkin lymphoma
- destructive metastasis to frontal sinus