Today’s case has been provided by my good friend Alberto Villanueva. PA radiograph of a 55-year-old male, taken during a workup for rectal carcinoma.
2. Pericardial cyst
3. Carcinoma of the lung
4. None of the above
More images will be shown next Wednesday. What do you see?
in my opinion it is difficult to determine in the plain film the origin of large masses adjacent to the mediastinum. I am showing today coronal and axial enhanced CTs.
What do you think?
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Findings: PA radiograph shows a rounded well-defined mass at the costophrenic angle in the lower left hemithorax (A, arrow). We can infer that the mass is anterior because is displacing the heart towards the right and it does not obliterate the para-aortic line.
In my opinion, when a large mass if adjacent to the midline it is difficult to determine whether it is mediastinal or pulmonary.
Coronal and axial enhanced CT show a solid mediastinal mass with areas of necrosis (B-C, arrows). The most common solid lesion in the cardiophrenic angle are enlarged lymph nodes, which usually are multiple and not very large. In big soft-tissue tumors of this area a thymic origin should be suspected. Although thymic tumors originate in the anterior superior mediastinum, they may slide down along the mediastinal planes and appear at the cardiophrenic angle in the lower mediastinum. Biopsy confirmed the diagnosis of thymoma.
Final diagnosis: mediastinal thymoma
Congratulations to Mohamed Abdulghaffarand MK who were the first to suggest the correct diagnosis
Teaching point: Remember that CT is very helpful in diagnosing cardiophrenic angle masses according to their radiographic density: fat (pericardial fat pad, Morgagni’s hernia); fluid (pericardial cyst) and soft-tissue ( lymphadenopahy and the occasional thymic tumour).