Idiopathic muscular hypertrophy of the duodenum.

There have not been any cases published of idiopathic muscular hypertrophy of the gastrointestinal tract in the past 20 years, mainly because it is a very rare condition of unknown aetiology. It is usually asymptomatic and presents mostly in the oesophagus of adult men. Our case involves a 69 year old female that presented with a 6 week history of abdominal discomfort and weight loss. An upper endoscopy showed a blockage at the second portion of the duodenum and the upper gastrointestinal series demonstrated stenosis in the same location. An exploratory laparotomy discovered a mass involving 5 cm of the second portion of the duodenum with wall thickening measuring up to 1.3 cm in thickness. The histological report was muscular hypertrophy with mild eosinophils. This is the first case reported with such a distinctive isolated involvement of the second part of the duodenum.