Round atelectasis as a complication of Legionnella pneumonia

Round Atelectasis: A Peculiar Pseudotumor Seen on Echocardiogram

Round atelectasis (RA) is a rare disorder most commonly occurring in the presence of chronic pleural effusions due to the formation of adhesions and resultant pulmonary collapse. The most common culprit to this disease is asbestosis, but other causes of pleural effusions such as congestive heart failure and pneumonia are reported in the literature. RA can occasionally mimic pulmonary cancers and should be identified to prevent the associated morbidity of tumor workup. We present a case of RA seen on echocardiogram, and then later on computed tomography mimicking a pleural tumor in a 58-year-old female with preexisting heart failure and recurrent pleural effusions. Consultation with radiology and recognition of RA prevented the unnecessary potential morbidity and mortality of further workup.

Causative factors, imaging findings, and CT course of round atelectasis

OBJECTIVE

To assess causative factors, associated imaging findings, and CT course of round atelectasis (RA).

MATERIALS AND METHODS

We retrospectively reviewed CT reports for "round" or "rounded atelectasis" over a 5-year time frame. Patients with at least 2 CT scans a minimum of 6 months apart were included. Electronic medical records and clinical and imaging follow-up was reviewed for all cases.

RESULTS

Study population included 50 individuals with mean age of 63 years, and 59 unique instances of RA. The most commonly associated etiologies were hepatic hydrothorax (26%, n = 13) and asbestos exposure (26%), followed by post-infectious pleural inflammation (22%), congestive heart failure (12%), and end stage renal disease (8%). RA was found in the right lower lobe in over half of cases (n = 30). Association with one or more pleural abnormality was identified in all cases, including thickening (88%), fluid (60%), or calcification (40%). Nearly one third (n = 19) demonstrated intra-lesional calcification. In those who underwent PET/CT (20%), lesions demonstrated an average SUV of 2.2 (range 0-7.8). CT course over mean follow up of 32 months (range 6-126 months), demonstrated RA to remain stable (n = 26) or decrease (n = 26) in size in the majority (88%) of cases.

CONCLUSION

Round atelectasis may arise from diverse etiologies beyond asbestos, and will most often decrease or remain stable in size over serial exams. Accurate identification may obviate the need for added diagnostic interventions.

Rounded atelectasis associated with pulmonary lymphangioleiomyomatosis

Rounded atelectasis is an unusual form of lung collapse that develops as a consequence of pleural diseases. Among a variety of conditions, asbestos inhalation has been attributed in most cases, but many other causes have also been implicated. Here, we describe the first case of rounded atelectasis and pneumothorax associated with pulmonary lymphagioleiomyomatosis.

Rounded atelectasis of the lung

Rounded atelectasis of the lung (RA) is a lesion well described in the medical literature, yet often very difficult to diagnose. In recent years, the widespread use of high-resolution imaging modalities employed in the struggle against cancer, coinciding with the peak of the asbestos epidemic, have boosted the detection frequency of RA. However, its differential diagnosis still poses a challenge to the pulmonary specialist and the radiologist, as little is known about its pathogenesis. Furthermore, the multifactorial etiology of RA and its occasional coexistence with lung cancer make the task of confidently ruling out malignancy sometimes daunting. This article attempts to provide an update on RA's etiology, radiological evaluation, clinical management, and prognosis based on recent advances in broadly available diagnostic modalities and minimally invasive interventional procedures. An exemplary case of post-tuberculous RA is illustrated, as RA often presents as an unusual finding of a fairly common disease.