Thoracic sarcoidosis (staging)

PulmonaryThoracic sarcoidosis can be staged on a chest radiograph with implications for prognosis although HRCT and FDG-PET provide more information to help guide treatment.  

Usage

Chest radiographs have been the mainstay of staging pulmonarythoracic sarcoidosis for many decades with fair interobserver concordance ⁶. However, this system correlates poorly with symptom severity, extrapulmonary disease, pulmonary function tests and need for treatment ³. HRCT and FDG-PET can provide more information than chest x-ray to help guide treatment decisions ³.

Classification

Scadding criteria

On PA chest radiographs, sarcoidosis can be classified into five stages ^1,2,6:

• stage 0: normal chest radiograph
  • frequency at presentation: 5-15%
• stage I: hilar or mediastinal nodal enlargement only
  • frequency at presentation: 25-65%
  • spontaneous resolution: 60-90%
• stage II: nodal enlargement and parenchymal disease
  • frequency at presentation: 20-40%
  • spontaneous resolution: 40-70%
• stage III: parenchymal disease only
  • frequency at presentation: 10-15%
  • spontaneous resolution: 10-20%
• stage IV: end-stage lung disease (pulmonary fibrosis)
  • frequency at presentation: 5%
  • spontaneous resolution: 0%

Although in general patients progress from one stage to the next, this system does not correlate particularly well with clinical severity ^1,2. In fact, chest x-ray appearances are often more dramatic than functional impairment ².

History and etymology

In 1961, Scadding published a classification system adapted from one initially proposed by Karl Warm ⁴. Sometimes sarcoidosis is described as being staged with Siltzbach system ³, although this paper was not published until 1967 ⁵, and in turn, makes reference to classification systems already in place.