Pulmonary mucosa-associated lymphoid tissue lymphoma forming a reversed halo sign from ground-glass opacity

The reversed halo sign (RHS) has been associated with various pulmonary diseases. We report a rare case of pulmonary mucosa-associated lymphoid tissue lymphoma forming a RHS from a ground-glass opacity (GGO). A 73-year-old man was followed-up for the GGO on his computed tomography images, which gradually extended peripherally. During the fourth year of follow-up, the GGO significantly evolved into a well-demarcated, oval lesion, with interlobular and intralobular septal thickenings, and multiple air spaces were surrounded by a well-defined thin consolidative rim, called the RHS. A pathologic study of the specimen via transbronchoscopic biopsy revealed pulmonary mucosa-associated lymphoid tissue lymphoma.