Findings: PA chest radiograph shows a rounded opacity in the right lower lung (A, arrow, located posteriorly in the lateral view (B, arrow). It has a sharp convex border, typical of an extrapulmonary lesion. In my opinion, none of the three diagnosis offered can be excluded.

Enhanced sagittal CT shows a gap in the posterior part of the right hemidiaphragm (C, arrow) through with retroperitoneal fat and an upper pole renal cyst have herniated (D, arrow).

Final diagnosis: right Bochdalek hernia with herniated renal cyst.

Congratulations to all participants. I wish you all a very happy holidays!

Teaching point: I admit this case is bizarre, but interesting enough to be shown as the last case of the year. And remember that any lesion close to the diaphragm may arise from below.