Simple and complicated hypertrophic pyloric stenosis in the adult.

Simple, primary, or idiopathic hypertrophy of the pyloric muscle in the adult resembles the congenital pyloric hypertrophy of infants, and no associated lesion, such as a peptic ulcer, is apparent. The hypertrophy, which narrows and elongates the pyloric canal, is limited to the muscle of the pyloric sphincter and, most commonly, mainly involves the circular muscle; sometimes it is focal. The condition is benign and may be treated by simple splitting of the muscle as in the congenital variety. Its recognition may, however, be difficult and it may be mistaken for a pyloric carcinoma radiologically, or at operation, so that an unnecessarily wide resection is performed. Similar muscle hypertrophy limited to the pyloric canal has been more commonly observed in association with both benign and malignant peptic ulceration not necessarily in the pyloric region (Kirklin and Harris, 1933; Desmond and Swynnerton, 1957), and it has also been noted with gastric polyposis (Prinz, 1939) and with hypertrophy of the mucosal rugae (Zacho, 1948). Such pyloric muscle hypertrophy has usually been called 'secondary', though a better term is 'complicated', since secondary implies that the associated lesion is the known cause of the hypertrophy. A recent review of simple hypertrophic pyloric stenosis in the adult (Christiansen and Grantham, 1962) commented on its rarity. With the 64 records collected from, or added to, the literature by North and Johnson (1950), these authors reviewed a further 56 reported since 1950, as well as adding two new case histories. Three further examples recorded by McNaught (1957), five by Feraru, Rosemond, Irons, and Zaino (1961), one by Woo-Ming, (1961), and one by McLaughlin and Madding (1962) bring the total so far described to 132. A personal experience of four adult patients with pyloric muscle hypertrophy in a year led to a search through just over 200 records at St. Bartholomew's Hospital listed from 1950 to 1959 under the heading 'pyloric stenosis', and seven more were traced. A further record was obtained from the Royal Masonic Hospital. In this paper we describe the clinical, radiological, and pathological findings in these 12 patients, six of whom had peptic ulcers (three duodenal, two gastric, and one pyloric). The six with simple hypertrophic pyloric stenosis can be added to the 132 previously recorded. Although uncommon we do not believe that adult pyloric hypertrophy is as rare as the literature seems to suggest.