EUS-guided trucut biopsy in establishing autoimmune pancreatitis as the cause of obstructive jaundice

The diagnosis of autoimmune pancreatitis can be difficult and often requires a larger specimen than can be provided by FNA alone to determine if the tissue sample obtained with EUS trucut biopsy (TCB) is sufficient to allow adequate histologic review to establish the diagnosis of autoimmune pancreatitis.

EUS TCB was performed in patients presenting with obstructive jaundice who were suspected of having autoimmune pancreatitis based on their clinical, laboratory and imaging studies. The charts were retrospectively reviewed to determine the feasibility of TCB.

Between August 2002 and June 2004, 3 patients with obstructive jaundice and suspected autoimmune pancreatitis (AIP) underwent EUS TCB. In each case, a diagnosis of pancreatic cancer also was considered, and surgical resection was the planned therapy before the patient underwent EUS TCB. Histologic review of the TCB specimens established the diagnosis of AIP in two patients and identified nonspecific changes of chronic pancreatitis in the third patient. EUS-guided FNA was performed in two of the 3 patients and failed to establish the diagnosis in either patient. Other than mild transient abdominal pain (n = 1), no complications were identified.

This preliminary study suggests that EUS TCB can safely establish the diagnosis of AIP. Doing so helps guide management and may help to avoid unnecessary surgery. Prospective studies are needed to verify these findings and to more clearly define the role of EUS TCB in these patients.