Galaxy Sign

, Joungho Han², Man Pyo Chung³ and Yeon Joo Jeong⁴

(1)

Department of Radiology Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, Republic of (South Korea)

(2)

Department of Pathology Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, Republic of (South Korea)

(3)

Department of Medicine Division of Pulmonary and Critical Care Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, Republic of (South Korea)

(4)

Department of Radiology, Pusan National University Hospital, Busan, Korea, Republic of (South Korea)

Abstract

A large pulmonary nodule composed of multiple small nodules and surrounded by many very smaller satellite nodules is called a galaxy sign [1] (Fig. 7.1).

Definition

A large pulmonary nodule composed of multiple small nodules and surrounded by many very smaller satellite nodules is called a galaxy sign [1] (Fig. 7.1).

Fig. 7.1

CT galaxy sign in a 23-year-old man with pulmonary sarcoidosis. (a, b) Consecutive thin-section (2.5-mm section thickness) CT scans obtained at levels of the right upper lobar bronchi show multifocal areas of CT galaxy sign (arrows) that are comprised of multiple small nodules and surrounded by many very small satellite nodules, particularly in the right upper lobe. Mediastinal window images (not shown here) demonstrated enlarged lymph nodes in the mediastinum and hilum, bilaterally

Diseases Causing the Sign

The nodule(s) with CT galaxy sign is (are) observed in patients with pulmonary sarcoidosis and active pulmonary tuberculosis [2] (Table 7.1) (Figs. 7.2 and 7.3).

Table 7.1

Common diseases manifesting as galaxy sign