The predominate pattern described include patchy ground glass opacity with superimposed perilypmhatic nodules which form coalesce to from mass in some regions. 

Microscopic description: Transbronchial biopsy and washing from the anterior segment of the right upper lobe showed numerous non-necrotizing, sharply circumscribed granulomas with paucity of inflammatory cells. The granuloma is also seen within the alveolar interstitium. The intervening alveolar space is normal with no evidence of fibrosis. 

The imaging and histology findings are consistent with the diagnosis of sarcoidosis. The case demonstrate an example of ground glass pattern of sarcoidosis on CT. Microscopically this is due to extensive granuloma infiltration of the pulmonary interstitium rather than an alveolar disease process.