Diagnosing hypertrophic pyloric stenosis: does size matter?

This retrospective study examines the size of the pyloric tumour at the time of surgery in 100 patients (76 boys, 24 girls) operated over a 2.75 years period from June 1993 to March 1996. The size of the pyloric tumour was classified into one of three categories (short, moderate or large) by the operating consultant and documented in the operation note. This study supports the view that the pyloric tumour increases in size with the progressing age of a baby. Nowadays the diagnosis of hypertrophic pyloric stenosis (HPS) is made on average 2 weeks earlier than in a similar study 4 decades ago. Two thirds of the patients in the subgroup with short- and moderate-size pyloric tumours did not require any imaging technique to arrive at the diagnosis. Unexpectedly a more frequent use of imaging techniques was required in the subgroup of large pyloric tumours; large tumours tend to present as an ill-defined fullness in the right upper quadrant rather than a distinct olive.