E5449. Black Holes in the Lung: A Constellation of Pulmonary Cystic Diseases
  1. Andressa Rosa; Hospital DF Star
  2. Leonardo Silva; Hospital DF Star
  3. Wagner de Paula; Hospital DF Star
  4. Lorena Varanda; Hospital DF Star
  5. Joalbo Andrade; Hospital DF Star
  6. Tiago Morato; Hospital DF Star
  7. Priscilla Neves; Hospital DF Star
True lung cysts are round, lucent, or low-attenuating spaces with a well-defined thin and regular wall (< 2–3 mm); they mostly contain air but can also be fluid-filled. Disperse cysts are usually found in near-normal aging lungs or are related to tobacco use, whereas multiple cysts should be of concern for cystic lung disease, a condition where cysts overrule normal lung parenchyma to some extent. However, not all lung lucencies are due to cystic conditions. Cavities are also lucent lesions that can be related to a myriad of diseases and should be differentiated from cysts by having a thicker (> 4 mm) and sometimes irregular wall. Besides, there are pitfalls that can mimic cystic lesions like emphysema, bronchiectasis, and honeycombing.

Educational Goals / Teaching Points
The purpose of this exhibit is to show a pictorial review of key imaging findings within pulmonary cystic disease and main differential diagnosis/mimickers, and provide an algorithm to simplify the evaluation of these lesions.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
To provide an better algorithm, we have divided the cystic conditions according to presence and absence of other findings and its mimickers: cystic disease without other lung findings; cystic disease with ground glass opacities; cystic disease with nodules associated; and mimickers of cystic conditions.

When approaching cystic lung disease one should first consider whether the finding is a ‘real cyst’ or an atypical manifestation of a common mimicker, e.g., metastasis or emphysema, then characterize its morphology and distribution. The aim of this education exhibit is to provide a brief review of the key imaging features of common cystic lung diseases and its confounders, supplying a framework for differential diagnosis.