Sarcoidosis, aka sarcoid (from the Greek 'sark' and 'oid' meaning "flesh-like") or Besnier-Boeck disease, is an immune system disorder characterised by non-caseating granulomas (small inflammatory nodules) that most commonly arises in young adults. The cause of the disease is still unknown. Virtually any organ can be affected; however, granulomas most often appear in the lungs or the lymph nodes.
Radiographic appearance in the lungs is that of upper lobe predominant perilymphatic nodules and/or bilateral hilar lymphadenopathy.
Late stage can develop fibrotic masses, emphysema, cysts, traction bronchiectasis, aspergillomas.
Differential includes silicosis, but history should help
- Stage 1 hilar lymphadenopathy
- Stage 2 hilar lymphadenopathy and reticulonodular infiltrates
- Stage 3 reticulonodular infiltrates
- Stage 4 fibrocystic sarcoidosis typically with upward hilar retraction, cystic & bullous changes