(DIAGNOSTIC IMAGING) – Awareness of variable imaging characteristics and behavior of thymic cysts over time should help guide clinical management.

Over more than five years of follow-up, thin-walled unilocular thymic cysts, as initially defined by magnetic resonance imaging (MRI), never developed irregular wall thickening, mural nodularity or septations, according to a study recently published in Radiology. The cysts, however, did show mural calcification, along with change in size, computed tomography (CT) attenuation and MR signal intensity over the same period.

“Our investigation highlights the intrinsic and longitudinal characteristics of unilocular thymic cysts that contribute to their misinterpretation as thymic neoplasms and lymphadenopathy at CT,” wrote Wariya Chintanapakdee, M.D., Chulalongkorn University in Bangkok, Thailand, and colleagues.

In this retrospective study, the researchers evaluated the imaging characteristics and longitudinal change of unilocular thymic cysts on CT and MRI over time. All chest MRI studies showing thymic cysts between July 2008 and December 2019 were included. If initial CT showed a thymic lesion, the patient was referred for MRI for characterization and the baseline MRI indicated a cystic lesion. To read more, visit Diagnostic Imaging.