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Complex Mass at Right Lung Base
roentgenogram 01 the month Complex Mass at Right Lung Base* RobertA. Lee, M.D. ; and Albert A. Nemce k ]« , M.D .
A 43-year-old nonsmoking man
was admitted for evaluation of two mass es at th e right lung base . A mass was first noted on a routine chest radiograph 14 years previously (Fig 1). The patient underwent bronchoscopic examination at that time, which was reported as unremarkable. In view of the patients age and lack of symptoms, it was decided to follow the lesion with ann ual chest radiographs. The right lower lobe mass remained stable in size and appearance for nine years. No interval films had been performed between 1983 and 1987, at which time a follow-up film showed a second mass superior to the previous mass (Fig 2). The original mass appeared unchanged. The patient remaine d asymptomatic. Noncontrast CT and transthoracic needle aspiration biopsy of the new mass were performed on an outpatient basis for further evaluation . Purule nt material was aspirated, which subseque ntly grew Pseudomonas aeruginosa . Following the biop sy, the patient developed fever, 'chills, and pleuritic right-sided chest pain which prompted adm ission to the hospital. A chest radiograph done at that time revealed a new, large right pleural effusion. Whi te blood cell count on admission was 12.8K with 80 percent segs, 8 percent lymphocytes, and 8 percent monocytes. A chest tube was placed and 1,700 ml of bloody fluid was withdrawn. Cultures of the pleural fluid were negative.
FIG URE
1
FIGURE
2
*From the Department of Radiology, Northweste rn University Medical School, Chicago. Reprin t requests : Dr: Lee, Radiology, Olson Pavilion, 710 North Fairban ks Court, Chicago 60611
CHEST I 94 I 2 I AUGUST, 1988
397
Diagnosis: Infected intralobar bronchopulmonary sequestration Due to the location of the lesions, the chronic nature of the original mass, and th e positive cultures, an infected sequestration was considered. A descending thoracic and upper abdominal aortogram was performed for further evaluation (F ig 3). An anomalous artery arising from the lower thoracic aorta was found to supply the lesions in the right lower lobe. Venous drainage was via pulmonary veins (not shown). Preoperative diagnosis of an intralobar bronchopulmonary sequestration was made. At surgery, the aberrant artery was identified and a right lower lobectomy was performed. Postoperative recovery was uneventful. Bronchopulmonary sequestration is a congenital mass of dysplastic pulmonary tissue that has no normal connections with the bronchial tree or pulmonary arteries. The isolation of the sequestration from the airway explains the nondiagnostic outcome of bronchoscopy 14 years previously. An aberrant artery arising from the aorta or one of its branches usually perfuses the sequestered lung. Sequestrations are classified as intralobar or extralobar depending on their pleural investments. Intralobar sequestrations lie contiguous to normal lung parenchyma and within the same visceral pleura. ' Venous drainage is usually via the pulmonary veins. There is a slight left-sided predominance with the posterior basal segments most often involved. Most patients with intralobar sequestration present with recurrent respiratory infections. In about 15 percent of the patients, other congenital abnormalities are identified. These include esophagobronchial diverticulum , diaphragmatic hernia, skeletal deformities, and cardiac abnormalities. 2 Extralobar sequestrations are enveloped by a separate pleural covering and usually have systemic venous drainage. They are related to the left hemidiaphragm in 80 percent of the cases. In 75 percent of cases, the sequestration is located between the diaphragm and the lower lobe . It may also be within or below the diaphragm. It is frequently (about 50 percent) associated with congenital abnormalities. The most common of these include diaphragmatic hernias, diaphragmatic defects, and other lung anomalies. 2 The diagnosis of bronchopulmonary sequestration should be considered with persistent or recurrent lower lobe infiltrates or masses, especially if the posterior basal segment is involved." Intralobar sequestrations are more likely to appear round or oval. Infections are more common in intralobar sequestrations and may result in communication with the airway resulting in an air-containing cystic mass. ' Infection may also cause enlargement or propagation of the sequestration due to the accumulation of purulent material, as was probably the case in our patient. 398
FIGURE
3
Extralobar sequestration is usually a pyramidalshaped homogenous mass at th e left lung base . Infection is less likely b ecaus e of th e pleural lining separating it from adjacent lung. Extralobar sequestrations are more likely to be discover ed in a child, occasionally as an asymptomatic mass associated with other congenital malformations. 2 Aortography is frequently performed preoperatively to establish the diagnosis and to plan surgery. Fatal exsanguination has occurred when an anomalous vessel was not recognized at surgery. Alternative methods of demonstrating the anomalous arterial supply have been reported using computerized tomography, 4 ultrasound," and magnetic resonance imaging. 6 The differential diagnosis of this chest film would include lung abscesses, metastatic neoplasm, Bochdalek hernia, bronchiectasis, and intrapulmonary bronchogenic cysts. Given the posterior basal location of the lesions, the chronic nature (14 years ), the patients lack of symptoms, and the positive cultures on aspiration, a diagnosis of infected bronchopulmonary sequestration is the most likely consideration. The patients post-aspiration biopsy symptoms of fever and pleuritic chest pain were in part due to hemorrhage into the pleural space. In addition, aspiration biopsy may have allowed some of the previously wellcontained purulent material within the sequestered lung to leak into adjacent lung parenchyma causing acute pneumonia. Aortography was performed to confirm the diagnosis and to plan surgery. Roentgenogram of the Mont h (Lee. Nemcek)
REFERENCES 1 Fraser RG, Pare JAE Pulmonary anomalies of developmental origin. In: Fraser RG, Pare JA:P, eds. Diagnosis of diseases of the chest, vol I, Philadelphia: Saunders, 1977; 602-55 2 Savic B, Birtel FJ, Tholen \tV; Funke HD, Knoche R. Lung sequestration: report of seven cases and review of 540 published cases. Thorax 1979; 34:96-101 3 Felson B. The many faces of pulmonary sequestration. Sem
Roentgenol i972; 7:3-16 4 Miller PA, Williamson BRJ, Minor GR, Buschi AJ. Pulmonary sequestration: visualization of the feeding artery by CT: J Computer Assist Tomog 1982; 6:828..;30 5 Thind CR, Pilling DW Case report. pulmonary sequestration: the value of ultrasound. Clin Radiol1985; 36:437-39 6 Oliphant L, McFadden RG, Carr TJ, Mackenzie DA. Magnetic resonance imaging to diagnose intralobar pulmonary sequestration. Chest 1987; 91:500-02
CHEST / 94 / 2 / AUGUST; 1988
399
A 43-year-old nonsmoking man
was admitted for evaluation of two mass es at th e right lung base . A mass was first noted on a routine chest radiograph 14 years previously (Fig 1). The patient underwent bronchoscopic examination at that time, which was reported as unremarkable. In view of the patients age and lack of symptoms, it was decided to follow the lesion with ann ual chest radiographs. The right lower lobe mass remained stable in size and appearance for nine years. No interval films had been performed between 1983 and 1987, at which time a follow-up film showed a second mass superior to the previous mass (Fig 2). The original mass appeared unchanged. The patient remaine d asymptomatic. Noncontrast CT and transthoracic needle aspiration biopsy of the new mass were performed on an outpatient basis for further evaluation . Purule nt material was aspirated, which subseque ntly grew Pseudomonas aeruginosa . Following the biop sy, the patient developed fever, 'chills, and pleuritic right-sided chest pain which prompted adm ission to the hospital. A chest radiograph done at that time revealed a new, large right pleural effusion. Whi te blood cell count on admission was 12.8K with 80 percent segs, 8 percent lymphocytes, and 8 percent monocytes. A chest tube was placed and 1,700 ml of bloody fluid was withdrawn. Cultures of the pleural fluid were negative.
FIG URE
1
FIGURE
2
*From the Department of Radiology, Northweste rn University Medical School, Chicago. Reprin t requests : Dr: Lee, Radiology, Olson Pavilion, 710 North Fairban ks Court, Chicago 60611
CHEST I 94 I 2 I AUGUST, 1988
397
Diagnosis: Infected intralobar bronchopulmonary sequestration Due to the location of the lesions, the chronic nature of the original mass, and th e positive cultures, an infected sequestration was considered. A descending thoracic and upper abdominal aortogram was performed for further evaluation (F ig 3). An anomalous artery arising from the lower thoracic aorta was found to supply the lesions in the right lower lobe. Venous drainage was via pulmonary veins (not shown). Preoperative diagnosis of an intralobar bronchopulmonary sequestration was made. At surgery, the aberrant artery was identified and a right lower lobectomy was performed. Postoperative recovery was uneventful. Bronchopulmonary sequestration is a congenital mass of dysplastic pulmonary tissue that has no normal connections with the bronchial tree or pulmonary arteries. The isolation of the sequestration from the airway explains the nondiagnostic outcome of bronchoscopy 14 years previously. An aberrant artery arising from the aorta or one of its branches usually perfuses the sequestered lung. Sequestrations are classified as intralobar or extralobar depending on their pleural investments. Intralobar sequestrations lie contiguous to normal lung parenchyma and within the same visceral pleura. ' Venous drainage is usually via the pulmonary veins. There is a slight left-sided predominance with the posterior basal segments most often involved. Most patients with intralobar sequestration present with recurrent respiratory infections. In about 15 percent of the patients, other congenital abnormalities are identified. These include esophagobronchial diverticulum , diaphragmatic hernia, skeletal deformities, and cardiac abnormalities. 2 Extralobar sequestrations are enveloped by a separate pleural covering and usually have systemic venous drainage. They are related to the left hemidiaphragm in 80 percent of the cases. In 75 percent of cases, the sequestration is located between the diaphragm and the lower lobe . It may also be within or below the diaphragm. It is frequently (about 50 percent) associated with congenital abnormalities. The most common of these include diaphragmatic hernias, diaphragmatic defects, and other lung anomalies. 2 The diagnosis of bronchopulmonary sequestration should be considered with persistent or recurrent lower lobe infiltrates or masses, especially if the posterior basal segment is involved." Intralobar sequestrations are more likely to appear round or oval. Infections are more common in intralobar sequestrations and may result in communication with the airway resulting in an air-containing cystic mass. ' Infection may also cause enlargement or propagation of the sequestration due to the accumulation of purulent material, as was probably the case in our patient. 398
FIGURE
3
Extralobar sequestration is usually a pyramidalshaped homogenous mass at th e left lung base . Infection is less likely b ecaus e of th e pleural lining separating it from adjacent lung. Extralobar sequestrations are more likely to be discover ed in a child, occasionally as an asymptomatic mass associated with other congenital malformations. 2 Aortography is frequently performed preoperatively to establish the diagnosis and to plan surgery. Fatal exsanguination has occurred when an anomalous vessel was not recognized at surgery. Alternative methods of demonstrating the anomalous arterial supply have been reported using computerized tomography, 4 ultrasound," and magnetic resonance imaging. 6 The differential diagnosis of this chest film would include lung abscesses, metastatic neoplasm, Bochdalek hernia, bronchiectasis, and intrapulmonary bronchogenic cysts. Given the posterior basal location of the lesions, the chronic nature (14 years ), the patients lack of symptoms, and the positive cultures on aspiration, a diagnosis of infected bronchopulmonary sequestration is the most likely consideration. The patients post-aspiration biopsy symptoms of fever and pleuritic chest pain were in part due to hemorrhage into the pleural space. In addition, aspiration biopsy may have allowed some of the previously wellcontained purulent material within the sequestered lung to leak into adjacent lung parenchyma causing acute pneumonia. Aortography was performed to confirm the diagnosis and to plan surgery. Roentgenogram of the Mont h (Lee. Nemcek)
REFERENCES 1 Fraser RG, Pare JAE Pulmonary anomalies of developmental origin. In: Fraser RG, Pare JA:P, eds. Diagnosis of diseases of the chest, vol I, Philadelphia: Saunders, 1977; 602-55 2 Savic B, Birtel FJ, Tholen \tV; Funke HD, Knoche R. Lung sequestration: report of seven cases and review of 540 published cases. Thorax 1979; 34:96-101 3 Felson B. The many faces of pulmonary sequestration. Sem
Roentgenol i972; 7:3-16 4 Miller PA, Williamson BRJ, Minor GR, Buschi AJ. Pulmonary sequestration: visualization of the feeding artery by CT: J Computer Assist Tomog 1982; 6:828..;30 5 Thind CR, Pilling DW Case report. pulmonary sequestration: the value of ultrasound. Clin Radiol1985; 36:437-39 6 Oliphant L, McFadden RG, Carr TJ, Mackenzie DA. Magnetic resonance imaging to diagnose intralobar pulmonary sequestration. Chest 1987; 91:500-02
CHEST / 94 / 2 / AUGUST; 1988
399