accp-seek board review question of the month A 51-Year-Old Man With a Complicated Medical History and Abnormal Chest Radiographic Finding* Marvin I. Schwarz, MD, FCCP
(CHEST 2001; 119:1948 –1950)
51-year-old man is referred for evaluation of an A abnormal chest radiograph finding showing a chest mass. The patient has no chest complaints. He has a diagnosis of COPD (FEV1, 2.0 L; 55% of predicted) and gave up smoking 7 years ago when he received a diagnosis of multiple sclerosis. This was followed by a diagnosis of Parkinson’s disease 3 years later. Soon after that, he developed an atrioventricular block requiring a permanent pacemaker. He developed spondylosis of the cervical spine with torticollis, and 1 year ago, he underwent a C2-T4 spinal fusion. This was complicated by postoperative bilateral aspiration pneumonia, from which he recovered. His vital signs are normal, and he has an arterial oxygen saturation of 94% while breathing ambient air. His lung examination reveals expiratory wheezes, and he has mild lower-extremity edema bilaterally, but there is no evidence of clubbing. Complete blood count and electrolyte levels are normal. His chest radiograph and high-resolution CT are shown in Figures 1– 4. Prior films are unavailable. What is the most likely cause of the radiographic abnormalities? A. B. C. D. E.
Peripheral adenocarcinoma Hamartoma Rounded atelectasis Acute pulmonary infarction Pulmonary arteriovenous fistula
*From the ACCP-SEEK program, reprinted with permission. Items are selected by Department Editors Richard S. Irwin, MD, FCCP, and John G. Weg, MD, FCCP. For additional information about the ACCP-SEEK program, phone 1-847-498-1400. Correspondence to: Marvin Schwarz, MD, FCCP, Pulmonary Sciences and Critical Care Medicine, University of Colorado Health Sciences Center, 4200 E. 9th Ave, Box C272, Denver, CO 80262; e-mail:
[email protected]. 1948
Figure 1. Chest radiograph of 51-year-old patient.
Figure 2. Chest radiograph, lateral view. ACCP-SEEK Board Review Question of the Month
Figure 3. High-resolution CT scan of lung.
Figure 4. Another view from high-resolution CT scan of lung.
CHEST / 119 / 6 / JUNE, 2001
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Answer: C. Rounded atelectasis Rounded atelectasis or “folded lung” is a benign asymptomatic condition that simulates a lung tumor. This is a localized form of lung collapse associated with pleural inflammation and fibrosis. It can follow any inflammatory pleural effusion that leads to fibrosis. Most frequently, it occurs with asbestos exposure, tuberculosis, parapneumonic effusions, a pulmonary infarction, uremic pleuritis, and nonspecific pleuritis. It is thought that pleuritis is the primary event that leads to fibrosis over a limited portion of the lung. As the fibrosis matures, it contracts, causing wrinkling and folding of the pleura. Since the elastic framework of the alveolar septae is connected to the visceral pleural internal elastic lamina, the folding of this pleural surface leads to collapse of the underlying lung. The chest radiograph, as was the case here, demonstrates a focal lung mass in the subpleural space, most often seen in the lower lobes. There are specific high-resolution CT criteria for diagnosing rounded atelectasis. These include a peripheral lung mass adjacent to the pleura that creates an acute angle with the thickened pleura. A curved appearance of vessels and bronchi as they enter the
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mass, at least two distinct margins of the mass, and blurring of the centrally directed margin caused by entering blood vessels. These features are evident in Figures 3 and 4. Rounded atelectasis does not enlarge with time and actually may resolve in weeks to a year. However, because many cases of rounded atelectasis are associated with lung cancer, follow-up is necessary. With respect to the other diagnostic choices, peripheral adenocarcinoma is often spiculated on the CT scan, and an arteriovenous fistula has definable entrance and exit blood vessels often found in the lower lobes, but is rarely if ever in a subpleural location. A hamartoma appears as a solitary intraparenchymal coin lesion, which may show “popcorn” calcification. Suggested Readings Batra P, Brown K, Hayashi K, et al. Rounded atelectasis. J Thorac Imaging 1996; 11:187–197 Hillerdal G. Rounded atelectasis: clinical experience with 74 patients. Chest 1989; 95:836 – 841 Voisin C, Fisekci F, Voisin-Saltiel S, et al. Asbestos-related rounded atelectasis: radiologic and mineralogic data in 23 cases. Chest 1995; 107:477– 481
ACCP-SEEK Board Review Question of the Month