Focal chronic pancreatitis mimicking pancreatic head carcinoma: are there suggestive features on ultrasound?

OBJECTIVE: Painless jaundice is one of the most common presentations of pancreatic head cancer. Chronic pancreatitis can also occasionally present with a mass or mass-like process in the pancreatic head, with the subsequent development of jaundice. In this retrospective review, we evaluate the clinical and imaging features of 22 patients presenting with painless jaundice, initially thought to have pancreatic head cancer and ultimately proven to have chronic focal pancreatitis, to determine whether there are any features on cross-sectional imaging to suggest the correct diagnosis. METHODS: Patients (n = 22) were identified from the medical and imaging records of more than 400 patients with an original diagnosis of pancreatic cancer who were seen at our institution from 1995 to 2003. Of the patients, 17 were men and 5 were women (age range 25 to 82 years, mean age 54 years). RESULTS: Initial ultrasound showed a large, hypoechoic, well-defined mass in the pancreatic head, varying in size from 3 to 7.5 cm; 14 of 22 masses were > 5 cm in maximal diameter. Diagnosis of focal pancreatitis was proven by surgical pathology in 14 cases and suggested by percutaneous biopsy in 3 cases; for all patients, prolonged imaging follow-up (at least 1 year) showed no disease progression or evidence of malignancy. The mean follow-up in our study group was 31 months (range 12 to 72 months). CONCLUSION: Male sex, large size of the pancreatic head mass (mean diameter 5.5 cm), and lack of atrophy of the pancreatic body and tail were the only features associated with chronic inflammation rather than neoplasm as an explanation for a pancreatic head mass. Chronic pancreatitis should be considered in the differential diagnosis of focal pancreatic masses, even in the absence of supporting clinical evidence.