Gastroenterology clinical image challenge: A 45-year-old man presented to the emergency department with a 10-day history of persistent dull right lower quadrant abdominal pain. This pain is on a background of a recent gastroscopy and colonoscopy performed six months ago for investigation of nausea, vomiting and rectal bleeding. Gastroscopy and colonoscopy findings include a medium sized hiatal hernia with reflux esophagitis and three small colonic polyps (<5 mm). He also suffers from seasonal sinusitis and mild chronic back pain. He smokes five cigarettes per day. His gastroesophageal reflux is managed by esomeprazole. On examination, he was afebrile, normocardic and normotensive (91 bpm and 125/85 mm Hg, respectively). Gastrointestinal examination revealed a soft abdomen with right lower quadrant tenderness and focal rebound and percussion tenderness. There was a palpable mass. Blood tests revealed a white blood cell count of 12.9 × 109/L and C-reactive protein of 302 mg/L.
What are the causes of a tender right lower abdomen with a palpable mass in the setting of a relatively unremarkable gastroscopy and colonoscopy?
To find out the diagnosis, read the full case in Gastroenterology.