European Journal of Radiology. 11 (1990) 156-158 Elsevier
156
EURRAD
00085
A rare acute pulmonary lesion after blunt chest trauma: a case report R.J. Versteylen’
and P.A.M. Van Leeuwen2
Departments of ‘Radiology and ‘Surgery, UniversityHospital Maastricht, The Netherlands (Received
12 January
1990; accepted
after revision 17 May 1990)
Key words: Chest, radiography;
Chest, Trauma
Case report A 52-year-old man was hit in a car accident. After admission to the hospital he proved to have a flail chest on the right side. There were no signs of respiratory distress. Chest X-rays revealed a fracture of the right scapula, nine fractured ribs on the right and two on the left side. Due to abdominal distress and positive peritoneal tap, laparotomy was performed in which a small laceration of the liver was found. Because of his serious chest trauma the patient was monitored and ventilated by PEEP. After 6 days, a large oval cavity measuring 8 by
Fig. 2. The pseudocyst has been drained (curved arrows) and diminished in volume. Drain in right pleural space to evacuate a considerable hematothorax (arrows). A persistent air leak on the right side was treated with a double-lumen ventilation tube (open arrows).
Fig. 1. Large oval cavity in the right lower lung (arrows). Note the hematothorax and multiple rib fractures on the right.
Address for reprints: R.J. Versteylen. Department of Radiology Academic Hospital Maastricht, Postbox 1918,620l BX Maastricht, The Netherlands. 0720-048X/90/$03.50
0 1990 Elsevier Science Publishers
10 cm was seen on the chest radiographs (Fig. 1). After drainage of the hematothorax, transthoracic puncture of the pseudocyst had to be performed due to the considerable tension which occurred and which interfered with the gas exchange. The high air leak in the remnant pseudocyst made separate ventilation of the lungs necessary, which was performed by double-lumen tube (Fig. 2). The air leak closed spontaneously and normal ventilation was possible again. The remnant pseudocyst with air fluid level and thick walls is seen on the CT-scan (Fig. 3). After 4 weeks, an abcess developed in the right lung and a small productive tistula was seen and injected with contrast medium. A CT scan confirmed the con-
B.V. (Biomedical
Division)
157
Fig. 3. Residual cavity of pseudocyst after 2 weeks. The drain had been removed. Note the thick walls (arrows). Later a fistula developed from this cavity to the anterior thoracic wall.
nection between fistula and abcess, and showed the abcess to be located in the former pseudocyst cavity (Fig. 4). Drainage and antibiotic treatment were performed for 6 weeks. This resulted in complete resolution of the cavity. The patient was finally discharged in a good condition. Discussion
Acute pulmonary lesions associated with blunt chest trauma are common and can easily be recognized [ 11.
Fig. 4. Draining of the infected residual cavity (arrow). Contrast in cavity after fistulography.
Immediate pulmonary pneumatocele or pseudocyst formation is rare and mostly described in case reports. Minor clinical symptoms, but obvious radiological signs, are characteristic for this type of injury. The symptoms are mostly mild and can include chest pain, cough and a slightly increased temperature. Fever and leucocytosis may be present. Treatment with antibiotics is indicated only in case of superinfection. Hemoptysis can be seen at an early stage and is related to evacuation of cyst fluid. The treatment is conservative. Occasionally surgical intervention takes place, when there is any doubt with regard to the nature of the lesion but this often proves unnecessary afterwards. The obvious history of trauma should prevent such action [ 21. In our case, a puncture was performed to relieve the tension in the cyst, causing restrictive failure of the lung. The characteristic pseudocyst appears early after trauma and the diagnosis is established by plain chest radiography. The lesion appears as an oval or circular lucency which can contain air or fluid. Sometimes associated surrounding pulmonary contusion can completely obscure the pseudocyst, becoming visible only after resolution of the contusion [ 31. If a pseudocyst is located adjacent to the inferior pulmonary ligament, air can escape between the two layers of this ligament, causing a traumatic paramediastinal cyst [4]. The pseudocyst is formed due to laceration within the lung parenchyma. The etiology is explained by the concussive forces applied to the chest, which can create sheering stress that exceeds the elastic properties of the lung. As a result, cavities can develop within the lung parenchyma. The walls of these pseudocysts are usually very thin containing only remnants of alveoli. After several days the wall may thicken as a result of surrounding pseudomembranes [ 51. This is shown in the CT scan made 2 weeks after the initial trauma. As yet, the use of CT in the diagnosis of traumatic pulmonary pseudocysts has seldom been reported [ 61. The differential diagnoses in adults include: lung abcess, cavitating carcinoma or tuberculosis. In children, postinflammatory pneumatocele, bronchial cyst or sequestration may be alternative diagnoses [7]. Most of the time the radiologist will be the first to spot a lucency on radiographs made in the intensive care unit, and he should be aware of the possibility that the lesion is a pulmonary pseudocyst. This may prevent unnecessary diagnostic procedures. Extreme caution and a reluctant attitude towards intervention of any kind should be taken. In our case puncture became necessary; however, it resulted in abcess formation several weeks later.
158
References 1 Fraser RG, Pare JAP. Diagnosis of diseases of the chest, Vol. 3, 1979; 1572-1576. 2 Shirakusa T, Araki Y, Tsutsui M, Motonaga R, Iwanaga M, Ogami H, Matsuba K. Traumatic lung pseudocyst. Thorax 1987; 42: 516-519. 3 Santos GH, Mahendra T. Traumatic pulmonary pseudocysts. Ann Thorac Surg 1979; 27: 359-362. 4 Ravin CE, Walker Smith G, Lester PD, Mcloud TC, Putman CE.
Posttraumatic pneumatocele in the inferior pulmonary ligament. Radiology 1976; 121: 39-41. 5 Fagan JF, Swischuk LE. Traumatic lung and paramediastinal pneumatoceles. Radiology 1976; 120: 11-18. 6 Black WC, Gouse JC, Williamson BRJ, Newman BM. Computed tomography of traumatic lung cyst: case report. J Comp Assist Tomogr 1986; 10: 33-35. 7 Sorsdahl OA, Powell JW. Cavitary pulmonary lesions following non-penetrating chest trauma in children. AJR 1965; 90: 872-875.
156
EURRAD
00085
A rare acute pulmonary lesion after blunt chest trauma: a case report R.J. Versteylen’
and P.A.M. Van Leeuwen2
Departments of ‘Radiology and ‘Surgery, UniversityHospital Maastricht, The Netherlands (Received
12 January
1990; accepted
after revision 17 May 1990)
Key words: Chest, radiography;
Chest, Trauma
Case report A 52-year-old man was hit in a car accident. After admission to the hospital he proved to have a flail chest on the right side. There were no signs of respiratory distress. Chest X-rays revealed a fracture of the right scapula, nine fractured ribs on the right and two on the left side. Due to abdominal distress and positive peritoneal tap, laparotomy was performed in which a small laceration of the liver was found. Because of his serious chest trauma the patient was monitored and ventilated by PEEP. After 6 days, a large oval cavity measuring 8 by
Fig. 2. The pseudocyst has been drained (curved arrows) and diminished in volume. Drain in right pleural space to evacuate a considerable hematothorax (arrows). A persistent air leak on the right side was treated with a double-lumen ventilation tube (open arrows).
Fig. 1. Large oval cavity in the right lower lung (arrows). Note the hematothorax and multiple rib fractures on the right.
Address for reprints: R.J. Versteylen. Department of Radiology Academic Hospital Maastricht, Postbox 1918,620l BX Maastricht, The Netherlands. 0720-048X/90/$03.50
0 1990 Elsevier Science Publishers
10 cm was seen on the chest radiographs (Fig. 1). After drainage of the hematothorax, transthoracic puncture of the pseudocyst had to be performed due to the considerable tension which occurred and which interfered with the gas exchange. The high air leak in the remnant pseudocyst made separate ventilation of the lungs necessary, which was performed by double-lumen tube (Fig. 2). The air leak closed spontaneously and normal ventilation was possible again. The remnant pseudocyst with air fluid level and thick walls is seen on the CT-scan (Fig. 3). After 4 weeks, an abcess developed in the right lung and a small productive tistula was seen and injected with contrast medium. A CT scan confirmed the con-
B.V. (Biomedical
Division)
157
Fig. 3. Residual cavity of pseudocyst after 2 weeks. The drain had been removed. Note the thick walls (arrows). Later a fistula developed from this cavity to the anterior thoracic wall.
nection between fistula and abcess, and showed the abcess to be located in the former pseudocyst cavity (Fig. 4). Drainage and antibiotic treatment were performed for 6 weeks. This resulted in complete resolution of the cavity. The patient was finally discharged in a good condition. Discussion
Acute pulmonary lesions associated with blunt chest trauma are common and can easily be recognized [ 11.
Fig. 4. Draining of the infected residual cavity (arrow). Contrast in cavity after fistulography.
Immediate pulmonary pneumatocele or pseudocyst formation is rare and mostly described in case reports. Minor clinical symptoms, but obvious radiological signs, are characteristic for this type of injury. The symptoms are mostly mild and can include chest pain, cough and a slightly increased temperature. Fever and leucocytosis may be present. Treatment with antibiotics is indicated only in case of superinfection. Hemoptysis can be seen at an early stage and is related to evacuation of cyst fluid. The treatment is conservative. Occasionally surgical intervention takes place, when there is any doubt with regard to the nature of the lesion but this often proves unnecessary afterwards. The obvious history of trauma should prevent such action [ 21. In our case, a puncture was performed to relieve the tension in the cyst, causing restrictive failure of the lung. The characteristic pseudocyst appears early after trauma and the diagnosis is established by plain chest radiography. The lesion appears as an oval or circular lucency which can contain air or fluid. Sometimes associated surrounding pulmonary contusion can completely obscure the pseudocyst, becoming visible only after resolution of the contusion [ 31. If a pseudocyst is located adjacent to the inferior pulmonary ligament, air can escape between the two layers of this ligament, causing a traumatic paramediastinal cyst [4]. The pseudocyst is formed due to laceration within the lung parenchyma. The etiology is explained by the concussive forces applied to the chest, which can create sheering stress that exceeds the elastic properties of the lung. As a result, cavities can develop within the lung parenchyma. The walls of these pseudocysts are usually very thin containing only remnants of alveoli. After several days the wall may thicken as a result of surrounding pseudomembranes [ 51. This is shown in the CT scan made 2 weeks after the initial trauma. As yet, the use of CT in the diagnosis of traumatic pulmonary pseudocysts has seldom been reported [ 61. The differential diagnoses in adults include: lung abcess, cavitating carcinoma or tuberculosis. In children, postinflammatory pneumatocele, bronchial cyst or sequestration may be alternative diagnoses [7]. Most of the time the radiologist will be the first to spot a lucency on radiographs made in the intensive care unit, and he should be aware of the possibility that the lesion is a pulmonary pseudocyst. This may prevent unnecessary diagnostic procedures. Extreme caution and a reluctant attitude towards intervention of any kind should be taken. In our case puncture became necessary; however, it resulted in abcess formation several weeks later.
158
References 1 Fraser RG, Pare JAP. Diagnosis of diseases of the chest, Vol. 3, 1979; 1572-1576. 2 Shirakusa T, Araki Y, Tsutsui M, Motonaga R, Iwanaga M, Ogami H, Matsuba K. Traumatic lung pseudocyst. Thorax 1987; 42: 516-519. 3 Santos GH, Mahendra T. Traumatic pulmonary pseudocysts. Ann Thorac Surg 1979; 27: 359-362. 4 Ravin CE, Walker Smith G, Lester PD, Mcloud TC, Putman CE.
Posttraumatic pneumatocele in the inferior pulmonary ligament. Radiology 1976; 121: 39-41. 5 Fagan JF, Swischuk LE. Traumatic lung and paramediastinal pneumatoceles. Radiology 1976; 120: 11-18. 6 Black WC, Gouse JC, Williamson BRJ, Newman BM. Computed tomography of traumatic lung cyst: case report. J Comp Assist Tomogr 1986; 10: 33-35. 7 Sorsdahl OA, Powell JW. Cavitary pulmonary lesions following non-penetrating chest trauma in children. AJR 1965; 90: 872-875.
