Frontal mucocele

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A frontal mucocele is a paranasal sinus mucocele in a frontal sinus and is the most common location of all the paranasal sinus mucoceles.

Clinical presentation

Mucocoeles in the frontal sinus may be asymptomatic with insidious onset or present with headaches and facial pain. Forehead (supraorbital) swelling and orbital cellulitis may also be present.

If there is orbital invasion, patients may have proptosis and diplopia.

Radiographic features

CT
  • homogeneously low attenuating expansile lesion involving one of the ethmoid air cells
  • does not enhance with contrast
  • may demonstrate bony erosion of the sinus walls. Sinus contents tend to have a homogenous appearance.
  • used for surgical planning
MRI
  • useful for defining intracranial extension or obstructing malignancy
  • contents of the mucocele produce different signal intesities depending on the amount of dessicated
  • T1
    • water-rich content: low signal (most common)
    • protein-rich content: high signal
  • T2
    • water-rich content: high signal (most common)
    • protein-rich content: low signal
    • may look like an air-filled sinus in advanced disease
  • T1 C+ (Gd): enhancement, if present, only occurs at the periphery
  • DWI: variable

Differential diagnosis  

Possible considerations include