Can We Differentiate Between Primary Sjögren Syndrome and Idiopathic Multicentric Castleman Disease Based on the Characteristics of Pulmonary Cysts?

Although regular and smooth-walled cysts were common in the 2 diseases, irregular and non-smooth-walled cysts were more often associated with iMCD than pSS. Nodules in iMCD tended to be larger and more numerous, and a close positional relationship between nodules and cysts was only observed in iMCD.