BACKGROUND
Groove pancreatitis (GP) is a rare and poorly studied form of chronic pancreatitis involving inflammation of the area bounded by the head of the pancreas, the common bile duct, and the adjacent loop of the duodenum. There is significant symptomatic and diagnostic overlap between GP and pancreatic adenocarcinoma, which can complicate the diagnosis of both conditions.
CASE REPORT
A 65-year-old man with a history of alcohol dependence presented with 4 weeks of post-prandial nausea, bloating, and abdominal discomfort that was initially believed to be due to GP based on symptoms and imaging findings. The initial computed tomography (CT) scan showed loss of the fat plane between the pancreatic head and the duodenum, consistent with GP. The patient’s clinical course continued to deteriorate despite conservative management. A subsequent CT scan showed a 1.9×1.5×1.6 cm pancreatic head mass, which was confirmed as adenocarcinoma on endoscopic ultrasound guided biopsy with IMP3 positivity and retained SMAD-4 expression on immunohistochemical staining, with T1N0M1 tumor staging (with metastatic disease due to peritoneal carcinomatosis) and markedly elevated tumor marker CA-19-9. His clinical course was complicated by malignant pyloric stenosis contributing to anorexia and malnutrition. He died 3 months after diagnosis.
CONCLUSIONS
This case illustrates how patients presenting with signs of chronic pancreatitis may instead have pancreatic adenocarcinoma. This case further illustrates how diagnostic re-evaluation is needed in patients with chronic pancreatitis who have progression of disease despite conservative management, with failure to thrive being a significant motivation for diagnostic re-evaluation in this example.

Keywords: Abdominal Neoplasms; Abdominal Pain; Cancer Pain; Failure to Thrive; Pancreatic Diseases; Pancreatic Neoplasms; Pancreatitis, Chronic