We report the case of a 67-year-old patient initially referred to our cardiothoracic surgery department for resection of a stage I (cT2N0M0) non-small cell lung carcinoma. At surgery, frozen sections following a right lower lobectomy revealed in situ squamous cell carcinoma, leading to an additional middle lobectomy. Postoperative chest radiographs showed a paracardiac opacity of moderate size, interpreted as postoperative loculated collection (Fig 1
) and, in the context of his excellent recovery, thought to be clinically irrelevant. The patient was discharged on postoperative day 8. Two days later, the patient consulted his primary care physician for persisting shoulder pain. Clinical examination was only remarkable for moderate right-sided subcutaneuous emphysema. A chest radiograph revealed the same opacity of moderate size. All laboratory values were normal. To further characterize that finding, a chest CT scan was performed, revealing a homogeneous mass (50 × 35 × 18 mm) occupying the right paracardiac costodiaphragmatic angle within which a 10-cm long, thin, linear structure of high density could be seen (Fig 2
). He was thus readmitted in our university hospital for further care management.