Sarcoid is characterized by well-formed, usually non-necrotizing, granulomas in many organs. In the lung, it has a range of appearances varying from individual granulomas to aggregated granulomas associated with nodular or occasionally linear scarring. At low power, sarcoid granulomas typically show a lymphangitic distribution, that is, concentration around bronchovascular bundles, interlobular septa, and pleura. Concentric onion-skin fibrosis around the granulomas is very characteristic of sarcoid and rare to nonexistent in infectious granulomas. Overall, the prognosis of sarcoid is good, but patients with extensive pulmonary fibrosis, cardiac involvement, or neurosarcoid may progress to fatal disease.