Adult hypertrophic pyloric stenosis in the form of focal pyloric hypertrophy is an uncommon but a well-established lesion. In most cases, clinical findings suggest malignancy, and despite advances in imaging techniques, preoperative diagnosis is difficult. Herein, an example of focal pyloric hypertrophy is presented with a review of the literature to emphasize the clinicopathological characteristics of this lesion. In a 43-year-old man with abdominal discomfort, endoscopy showed a 1.5 cm nodular lesion near the pylorus that necessitated surgery to exclude malignancy. Pathological examination allowed the diagnosis of focal pyloric hypertrophy. The present case and the review revealed that focal pyloric hypertrophy is a male dominant lesion in middle-aged patients. The clinical diagnosis is problematic, and its initial diagnosis depends on a high clinical suspicion in patients with upper gastrointestinal system complaints irrespective of the duration of the symptoms. It is not known whether it is a separate entity from the diffuse form. Although both are similar in a clinical point of view, etiopathogenetic studies are required to clarify their differences completely. Moreover, the rare occurrence of focal pyloric hypertrophy and the lack of diagnostic clinical findings do not exclude its consideration in the differential diagnosis, especially in patients with gastric outlet obstruction.
Keywords: Adult hypertrophic pyloric stenosis; Focal pyloric hypertrophy; Gastric outlet obstruction.