Wegener granulomatosis


Key points

  • Definition: Wegener granulomatosis (WG) is a systemic vasculitis causing necrosis and granulomatous inflammation, often presenting with a “runny nose.” Without modern treatment, most patients would quickly progress to death within a few short months.

  • Synonym: granulomatosis with polyangiitis.

  • Classic clue: Middle-aged Caucasian, sent for sinus examination for a “runny nose,” is found to have a medial orbital mass in addition to adjacent ethmoid sinus disease.

Imaging

Computed tomography features

  • Computed tomography (CT) is good for demonstrating destruction of bony orbital wall.

  • See magnetic resonance imaging (MRI) findings later.

Magnetic resonance imaging features

  • Intraorbital WG involvement is usually accompanied by paranasal sinus involvement.

  • Decreased T2 signal (relative to orbital fat) is helpful in suggesting the diagnosis.

  • 86% unilateral, 14% bilateral.

  • Two thirds have coexistent orbital and sinus disease with bony erosion.

  • One third have orbital disease without sinus disease.

  • 41% solely extraconal, 44% combined intraconal and extraconal, 6% primarily orbital apex, and 6% intraconal with muscular involvement.

  • T1 hyperintense to orbital fat (see Figure 48-2 , A, C, and E ).

    FIGURE 48-1 ■, A, Coronal nonenhanced computed tomography (NECT) through orbits reveals irregular mass medially destroying adjacent orbital wall with concomitant soft tissue density in ethmoid sinus. B, Axial contrasted CT shows soft tissue mass in medial orbit isointense with EOM, with abnormality involving adjacent ethmoid sinus. The orbital component is predominantly extraconal but also involves muscles.

    FIGURE 48-2 ■, A, T1 coronal shows conspicuous mass in upper outer portion of right orbit and abnormal signal in both ethmoids. Loss of medial orbital cortex OU. Extensive prior maxillary surgery bilaterally. B, Coronal T1 Gd fat saturation shows abnormal enhancement of right orbital mass and ethmoid sinuses. Extensive sinus surgery with bilateral antral windows and air/fluid levels. Absent nasal septum and portions of turbinates. Breech of medial orbital walls OU with loss of cortical bone. C, Axial T1 through orbit shows abnormal signal in ethmoids and lateral right orbit. D, Axial T1 Gd fat saturation shows abnormal enhancement of right orbital mass and ethmoid sinuses. E, Axial T1 at higher level showing mass in lateral right orbit. F, Axial T1 Gd shows heterogeneous enhancement of right orbital mass involving LG with multiple tiny internal areas of decreased signal.

  • T1 gadolinium (Gd) shows heterogeneous enhancement with multiple tiny internal areas of decreased signal (see Figure 48-2 , B, D, and F ).

Clinical issues

Signs and symptoms

  • Signs and symptoms are nonspecific and extremely variable, frequently delaying diagnosis.

  • Most patients first show symptoms of rhinitis.

Epidemiology

  • Incidence is ten cases per million per year.

  • Mainly occurs in middle-aged persons, but has been reported in younger and older patients.

  • 90% of patients are Caucasian.

Prognosis

  • 40% encounter exacerbations but most react tolerably to treatment.

  • May require surgical intervention for sinusitis or tracheal stenosis.

  • Relapses may be prolonged and problematic.

  • More than 85% have long-term complications including chronic renal failure and hearing loss.

  • 1-year mortality rate before steroids was 90%.

  • With the availability of cyclophosphamide in the 1970s, 5-year survival improved to 87%.

  • Requires long-term immunosuppressive therapy.

You're Reading a Preview

Become a Clinical Tree membership for Full access and enjoy Unlimited articles

Become membership

If you are a member. Log in here