Paraduodenal pancreatitis as diagnostic challenge: clinical and morphological features of patients with pancreatic pathology involving the pancreatic groove.

Background: Paraduodenal pancreatitis (PP) is an inflammation involving the groove zone, delimited by the duodenum lumen, bile duct, and the head of the pancreas. This area may also be involved during acute pancreatitis (AP). The differential diagnosis is clinically relevant, since PP generally persists, whereas AP resolves. Hence, we compared a cohort of patients with PP and AP involving the groove area. Methods: We retrospectively evaluated patients with pathology involving the groove area. The primary aim was to define the diagnostic features of PP compared to non-PP pancreatitis involving the groove area. PP was diagnosed by imaging, while AP was diagnosed according to the revised Atlanta classification and the clinical course, to exclude chronic pancreatitis. Results: The study population consisted of 37 patients (32 men, age 56.9±9.1 years), 25 with a diagnosis of PP (23 men, mean age 54.9±8.5 years), and 12 (9 men, mean age 61.2±9.2 years) with AP involving the groove. All 25 patients with PP and 4 (33.3%) with AP reported a history of alcohol abuse, 23 patients (92%) with PP, and 3 (25%) with AP had a history of smoking. On imaging, PP patients presented a significantly thicker duodenal wall compared to the AP group (P=0.010). Chronic pancreatitis in the body/tail and exocrine insufficiency was prevalent in PP (P<0.001 and P=0.02). The medial displacement of the gastroduodenal artery was more frequent in the PP group (P=0.011). Conclusion: PP has a different clinical and imaging profile compared to AP involving the groove area.