Underdiagnosis of umbilical hernias in CT scans in a multicenter study - the radiologically neglected pathology and its surgical implications.

Purpose: Umbilical hernias (UH) have a higher prevalence than previously considered. With the high workload radiologists must endure, UH can be missed when interpreting a computed tomography scan (CT). The clinical implications of its misdiagnosis are yet to be determined. Unreporting could lead to content lesions in surgical approaches and other potential complications. The aim was to determine the prevalence of UH using CT scans, and the incidence of radiological reporting.

Methods: A multicenter, cross-sectional study was performed in four tertiary-level hospitals. CT scans were reviewed for abdominal wall defects at the umbilicus, and radiological reports were examined to compare findings. In the case of UH, transversal, anteroposterior, and craniocaudal lengths were obtained.

Results: A total of 1557 CTs were included, from which 971 (62.4%, 95% CI 0.59-0.64) had UH. Out of those, 629 (64.8%, 95% CI 0.61-0.67) of the defects were not included in the radiological report. Smaller UH (x̄: 7.7 × 6.0 mm) were more frequently missed. Of the reported UH, 187 (54.7%) included at least one axis measurement, 289 (84.5%) content description, and 146 (42.7%) whether or not there were complication signs.

Conclusion: There is a high prevalence of UH, and a high incidence of under-reporting. This raises the question of whether this is a population-based finding or the norm worldwide. The reason of under-reporting and the clinical implications of these must be addressed in further studies.