Clinicopathologic characteristics of pulmonary acinar sarcoidosis

In 101 patients with histopathologic and clinical features compatible with sarcoidosis, a radiologic acinar pattern occurred in about 20% and was always accompanied by bilateral hilar lymphadenopathy. The radiologically acinar pattern histopathologically revealed noncaseating epithelioid granulomas and accumulations of macrophages in the alveolar spaces. Blood vessels were usually not affected by granulomas. On the other hand, a reticulonodular pattern histopathologically showed granulomas with centrally situated veins. The acinar form seems to represent the early stage of pulmonary sarcoldosis, producing primarily intra-alveolar lesions.