Incidental Cystic Tumor in the Pancreas: Observe or Operate?

Abstract

Question: A 27-year-old woman of Asian descent was referred to our department for resection of an incidentally diagnosed cystic pancreatic head tumor. The patient reported episodic back and epigastric pain as well as fatigue for 2 months, which led to the diagnostic workup. There was no history of pancreatitis, jaundice, vomiting, weight loss, fever, or night sweats. Physical examination and laboratory tests were unremarkable. She had last visited her home country, Thailand, >1 year ago. Magnetic resonance imaging (MRI; Figure A) showed a mass of the pancreatic head (encircled) with solid (blunt arrow) and cystic (arrow) areas. The mass was irregularly enhanced in the solid portion and the cystic wall when gadolinium was used. Heterogeneous iso- and hypointensity associated with high signal intensity corresponding to hemorrhage were observed. The portal vein was severely compressed and possibly infiltrated by the tumor (short arrow). Magnetic resonance cholangiopancreatography (MRCP; Figure B) disclosed a discrete compression and extrahepatic dilatation (long arrow) of the distal bile duct. The pancreatic duct did not show signs of obstruction (short arrow). There was evidence of enlarged peripancreatic and hepatic hilar lymph nodes on MRI and endosonography. Chest x-ray was normal. What is the diagnosis in this case? Should a Whipple procedure be performed? See the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI. At laparotomy, frozen section examination of lymph nodes of the hepatoduodenal ligament disclosed caseating granulomas. There was destructive infiltration of the portal vein by the pancreatic head mass, so a pylorus-preserving pancreatoduodenectomy with en bloc portal venous resection was performed (Figure C; square, pancreatic head; triangle, duodenum; encircled, area of massive caseating granulomatous inflammation; *, portal venous resection margin; long arrow, compressed bile duct; short arrow, pancreatic duct; blunt arrow, enlarged peripancreatic lymph node). Histopathologic workup disclosed massive granulomatous inflammation (Figure D, E, triangle mark) and caseating necrosis (Figure E, square mark). DNA specific for Mycobacterium tuberculosis was detected in the pancreatic lesion. Computed tomography of the chest showed diffuse, micronodular, parenchymal lesions reminiscent of miliary tuberculosis. Tuberculostatic therapy was started. Three months after the operation, the patient is free of complaints. Pancreatic tuberculosis is a very rare finding, even in the setting of miliary tuberculosis, which represents the most common cause.1Evans J.D. Hamanaka Y. Olliff S.P. et al.Tuberculosis of the pancreas presenting as metastatic pancreatic carcinoma A case report and review of the literature.Dig Surg. 2000; 17: 183-187Crossref PubMed Scopus (23) Google Scholar The typical patient is a young woman from a region with a high prevalence of tuberculosis, presenting with a short history of abdominal pain and a cystic pancreatic head mass. Unlike malignancy or chronic pancreatitis, tuberculotic lesions usually do not cause irregularities of the pancreatic duct seen on endoscopic retrograde cholangiopancreatography or MRCP.1Evans J.D. Hamanaka Y. Olliff S.P. et al.Tuberculosis of the pancreas presenting as metastatic pancreatic carcinoma A case report and review of the literature.Dig Surg. 2000; 17: 183-187Crossref PubMed Scopus (23) Google Scholar Vascular complications of pancreatic tuberculosis have only been reported in three cases as stenosis of the portal vein, encasement of the splenic vein,2De Backer A.I. Mortele K.J. De Keulenaer B.L. et al.Vascular involvement secondary to tuberculosis of the abdomen.Abdom Imaging. 2005; 30: 714-718Crossref PubMed Scopus (14) Google Scholar and massive gastrointestinal bleeding from a peripancreatic artery.1Evans J.D. Hamanaka Y. Olliff S.P. et al.Tuberculosis of the pancreas presenting as metastatic pancreatic carcinoma A case report and review of the literature.Dig Surg. 2000; 17: 183-187Crossref PubMed Scopus (23) Google Scholar Because of the life-threatening complications of vascular involvement, we advocated for a Whipple procedure with en bloc portal venous resection in this case.