e-CASES: Chest X-ray classification
Chest X-ray changes are divided into four stages:
Stage 1: bihilar lymphadenopathy
Stage 2: bihilar lymphadenopathy and reticulonodular infiltrates
Stage 3: bilateral pulmonary infiltrates
Stage 4: fibrocystic sarcoidosis typically with upward hilar retraction, cystic and bullous changes
Although patients with type I X-rays tend to have the acute or subacute, reversible form of the disease while those with types II and III often have the chronic, progressive disease, these patterns do not represent consecutive "stages" of sarcoidosis. Thus, except for epidemiologic purposes, this X-ray categorization is mostly of historic interest.