Traumatic pulmonary pseudocysts mimicking a congenital malformation of the lung

Traumatic Pulmonary Pseudocysts (TPPs) are a rare consequence of thoracic trauma that is seen disproportionately in young adults and paediatric populations. In this case report, we detail a case of a TPP initially misdiagnosed on imaging as a Congenital Cystic Adenomatoid Malformation (CCAM). Conservative management and monitoring for resolution of TPP is highly effective as in most cases it self-resolves without issue or need for intervention. This contrasts with the surgical treatment often indicated for symptomatic CCAMs. Clearly, failure to recognize TPP as a rare but important differential of pulmonary cystic lesions in the context of trauma can lead to significant distress for the patient's family, over investigation and unnecessary or harmful interventions. We also review in this article the literature surrounding the radiological appearances, clinical features and management of both conditions.