INTRODUCTION: Traumatic pulmonary pseudocyst (TPP) is an uncommon manifestation of blunt chest trauma in young adults. This should be considered in the differential diagnosis in patients sustaining blunt chest trauma.
CASE PRESENTATION: A healthy 27 year old man was seen after blunt trauma to his right chest while playing rugby. He was complaining of right lower chest pain and some streaky hemoptysis. There was no history of dyspnea, fever, chills, nightsweats. He had no prior pulmonary disease. He was not on any medication and denied alcohol abuse or use of recreational drugs. On examination he was comfortable at rest with normal vital signs. There was no lymphadenopathy or clubbing of fingers. There was mild chest wall tenderness on the lateral lower right chest. Chest was clear to auscultation. A chest radiograph was unremarkable and did not show rib fractures. A chest CT scan was obtained. Figure 1 shows areas of pulmonary contusion on the affected side of the right chest. Figure 2 shows a pulmonary pseudocyst on the right lower lung.
DISCUSSIONS: TPP manifests within the first 24 hours after blunt chest trauma in the majority of cases or up to fourteen days post-injury. Symptoms are non-specific and include cough, chest pain, hemoptysis, and shortness of breath. Physical examination findings are unremarkable and are usually restricted to crackles on the affected chest. Most reported cases of TPPs have concurrent lung injuries such as pulmonary contusion, hematoma, hemopneumothorax, and pneumothorax.1 Chest radiographs have a diagnostic yield ranging from 24–50% whereas chest CT scans can have a yield of 100%. TPPs, which may be uni- or bilateral, are usually subpleural lesions commonly affecting the lower lobes. Contused pulmonary parenchyma surrounds these thin, irregularly walled lesions, which lack epithelial lining. TPPs may contain air-fluid levels that result from bleeding from the surrounding vessels.1TPP can occur at almost any age group but majority of cases are 30 years old or younger. When a young adult gets involved in a blunt trauma, compression of an elastic thorax with resultant negative intrathoracic pressure on chest recoil causes parenchymal laceration, and because of the normal elastic recoil of the lung, air and fluid escape into the contusion-induced cavities. In younger patients, the greater compliance of the chest wall allows better transmission of the force of impact to the lung, and presumably is responsible for the higher frequency of this lesion in young adults.2 TPPs usually follow a benign course. Pseudocysts change in size and shape and may become larger during the first two weeks of observation. They eventually get smaller until complete resolution in 1–6 months.2 For the most part, pseudocyts are treated conservatively. For uncomplicated cases, serial chest X-rays are sufficient until resolution of the cysts, unless the patient has persistent fever or leukocytosis suggesting super-infection. Small infected cysts may respond to antibiotics alone or may require CT–guided percutaneous drainage if with clinical deterioration. Surgical resection is recommended if the infected cysts are more than 6 cm or if with massive pulmonary hemorrhage.1 TPPs usually have an excellent prognosis since majority of the cases are uncomplicated.
CONCLUSION: TPP is an uncommon manifestation seen in young adults after blunt chest trauma. It generally follows a benign clinical course but complications necessitating antibiotics and surgical drainage may arise.
DISCLOSURE: Jose Angelo De Dios, No Financial Disclosure Information; No Product/Research Disclosure Information