Imaging Case of the Week 171 Answer

The erect chest x-ray shows a crescent of air under the left hemi-diaphragm, suggestive of pneumoperitoneum.

There is also a tooth-like calcific density in the left adnexal region. This is likely to represent a left ovarian dermoid.

Erect chest x-ray, pneumoperitoneum

Left ovarian dermoid

This patient went on to have a CT scan of the abdomen, which confirmed pneumoperitoneum arising from a perforated peptic ulcer. The CT also showed a 6cm left ovarian dermoid cyst.

coronal CT pneumoperitoneum

sagittal CT pneumoperitoneum