Galaxy sign of sarcoidosis


The galaxy sign refers to a pulmonary nodule formed by the confluence of several small nodules. The center of the nodule is dense, and the periphery is less concentrated resulting in an irregular border.

The galaxy sign is most commonly described in sarcoidosis, but is also seen in other conditions such as tuberculosis, progressive massive fibrosis and even tumors. However, the identification of the galaxy sign favors a benign etiology.