The amount of calcifications in pseudoxanthoma elasticum patients is underestimated in computed tomographic imaging; a post-mortem correlation of histological and computed tomographic findings in two cases.

Objectives: Pseudoxanthoma elasticum (PXE) is a rare genetic disorder, characterised by elastic fibre degeneration and calcifications in multiple organ systems. Computed tomography (CT) imaging is a potential method to monitor disease progression in PXE patients; however, this method has not been validated. The aim of this study was to correlate histological and computed tomographic findings in PXE patients to investigate the ability of CT scanning to detect these alterations.

Methods: Post mortem total body CT scans were obtained from two PXE patients (a 69-year-old male and 77-year-old female). Autopsy was performed, and 38 tissue samples of the first and 45 tissue samples of the second patient were extensively investigated histologically. The findings were compared with the CT scans.

Results: Degenerated and calcified elastic fibres and calcifications were histologically found in the skin, subcutaneous fat, heart, arteries and pleura and around the oesophagus. On CT imaging only the intradermal alterations of the skin and the larger vascular calcifications were detected. The smaller PXE-related abnormalities were not visible on CT.

Conclusions: With CT imaging vascular calcifications and skin alterations can be monitored in PXE patients. However, many of the subtle PXE-related abnormalities found in other organ systems during the autopsy were not visualised by CT scans. Furthermore, we extended the current knowledge on the disease location of PXE with subcutaneous, oesophageal and pleural lesions.

Teaching Points: • CT can be used to monitor gross vascular calcifications in PXE patients. • Many subtle PXE-related abnormalities are not visualised by CT scans. • PXE-related alterations can also be found in oesophagus, pleura and subcutaneous fat.