ABSTRACT:The patient is a 57-year old Caucasian female who presented with right upper quadrant pain and obstructive jaundice and was diagnosed with resectable pancreatic cancer. She underwent pancreaticoduodenectomy (PD) after preoperative biliary stenting. She subsequently presented to the clinic, where it was noticed that she had an elevated CA 19-9. CT C/A/P revealed multiple new liver lesions.
Case Presentation
DR. ARVIND DASARI: The patient initially presented to the ER at our hospital with right upper quadrant pain and obstructive jaundice. Radiographic evaluation showed a 2.7-cm mass in the head of the pancreas.
Subsequent work-up including EGD/EUS with FNA and CT scans revealed cT3N0M0 pancreatic head adenocarcinoma invading the duodenum. The patient also underwent dilatation of a malignant common bile duct stricture with placement of a plastic stent. Given that the patient did not have any evidence of metastatic or locally advanced unresectable disease, she underwent pancreaticoduodenectomy (PD) six weeks after initial diagnosis. Pathology revealed a 3.1-cm, poorly differentiated adenocarcinoma invading the duodenum with extensive lymph node involvement consistent with pT3 N1 disease. She was seen in the oncology clinic four weeks after her resection for a discussion about adjuvant therapy.
The patient had no other medical problems and was working full time prior to her diagnosis. Her father died of an unknown lymphoma and her mother was a laryngeal cancer survivor. Complete physical exam was unremarkable except for her surgical scar, which was healing well. Lab work revealed normal blood counts, electrolyte panel, and renal function. Liver tests that were elevated at the time of presentation had also normalized. CA19-9 was 387 U/ml (normal range 0-35 U/ml) at time of initial diagnosis and 483 U/ml at the time of the clinic visit. Repeat staging scans were done a week after her initial clinic vist and showed new hypodense liver lesions.
FIGURE 1A 2.7 cm hypodense, hypovascular mass (arrows) demonstrated in pancreatic head by portal venous phase dynamic CT scan consistent with pancreatic ductal adenocarcinoma. FIGURE 1B  The double duct sign of pancreatic ductal andenocarcinoma. A more superior scan through the pancreatic bed demonstrates dilation of the intrapancreatic common bile duct (long arrow). The main pancreatic duct (short arrow) is also dilated with associated postobstructive atrophy of the pancreatic body. FIGURE 1C  At the hepatic hilum, there is marked dilation of the common hepatic duct (long arrow) above the cystic duct insertion (short arrow). FIGURE 1D  Intrahepatic bile duct dilation is demonstrated in the liver as serpiginous hypodense tubular structures running parallel to the intrahepatic portal vein branches (arrows). FIGURE 2  Followup scan after pancreaticoduodenectomy, demonstrates new focal hypodense lesion (arrow) in the liver during the arterial phase of dynamic CT consistent with metastasis of pancreatic ductal adenocarcinoma. Note pneumobilia associated with bilioenteric anastomosis. |
Radiographic Evaluation/Pre-operative staging
DR. ARVIND DASARI: Dr. Russ, Could you describe the radiographic findings in this patient?
DR. PAUL RUSS: The initial CT scan of the abdomen with intravenous and oral contrast revealed a 2.7-cm, hypodense, hypovascular, solid mass in the head of the pancreas and also involving the uncinate process. In addition, there was dilatation of the pancreatic, intrahepatic and extrahepatic ducts without any evidence of distant metastatic or lymph node involvement. However, the second CT scan done, at the time of her clinic visit, showed post-surgical changes with an ill-defined soft tissue mass in the operative bed. There were also five new hypodense lesions in the liver, with the largest lesion in the anterior segment measuring 1.3 × 1.5 cm. There were two lesions in the dome, measuring 1.1 cm and 8 mm, along with two additional subcentimeter lesions in the right lobe (Figures 1A-1D, 2).
DR. ARVIND DASARI: Are these findings typical of metastatic pancreatic cancer?
DR. PAUL RUSS: Because pancreatic adenocarcinoma is typically hypovascular compared to background pancreas and liver, the primary neoplasm is depicted as hypodense to the pancreas, and metastases as hypodense to the liver. However, some pancreatic adenocarcinomas remain occult, even with the use of advanced CT techniques, and in those cases the diagnosis can sometimes be surmised by using indirect, secondary signs like pancreatic and/or bile duct dilatation, and post-obstructive pancreatic atrophy. In this case, we see one of the typical hypodense lesions consistent with metastatic pancreatic cancer.
DR. ARVIND DASARI: What is the sensitivity and specificity of CT scans in staging pancreatic cancer?
DR. PAUL RUSS: CT scans can be > 90% sensitive for diagnosing primary pancreatic lesions greater than 2 cm, but their sensitivity is less for smaller lesions. [1] CT scans also have a high sensitivity (> 90%) and specificity (>80%) in demonstrating vascular invasion.[2] CT scans are also invaluable in staging and are sensitive in diagnosing macroscopic vascular invasion and liver metastases, but are not as useful in assessing lymph node and peritoneal metastases.[3] CT scans are also very sensitive in detecting liver metastases larger than 1 cm, but lesions smaller than 1 cm can be problematic since small, incidental, benign hepatic lesions are commonly depicted by CT.[4] Given the multiple lesions, the typical radiographic appearance of the liver lesions in the setting of an elevated CA19-9, these findings are most consistent with recurrent metastatic pancreatic cancer.
DR. ARVIND DASARI: There was significant discrepancy between the pre-operative clinical staging and the final pathological lymph node staging. Would the patient have benefited from additional staging work up?
DR. PAUL RUSS: MR and PET are two radiographic modalities that can be considered, but which are less commonly used in detecting and staging pancreatic cancer. A meta-analysis showed that the sensitivity of MR for diagnosing pancreatic adenocarcinoma was somewhat inferior to spiral CT (84% vs 91%), but that for determining resectability, the two modalities were equivalent.[5] It is reported that MR has an accuracy of 91% in correctly diagnosing sub-centimeter hepatic lesions as benign vs malignant.[6] Magnetic resonance cholangiopancreatography (MRCP) has been shown to have a sensitivity and specificity of 85% and 96%, respectively, in differentiating an inflammatory pancreatic mass from a conventional pancreatic carcinoma.[7] Thus, MR and MRCP can be used as an adjunct to multidetector CT (MDCT) in selected cases.[4] Given its low spatial resolution, PET scan alone is not useful in locoregional staging, but it could have a role in diagnosing metastatic disease. However, fused PET/CT scan, which combines the functional and anatomical information of both modalities, shows promise in imaging patients with pancreatic adenocarcinoma.[4]
DR. ARVIND DASARI: Dr. McCarter, what is the utility of laparoscopy in staging patients with pancreatic cancer?
DR. MARTIN McCARTER: Laparoscopy is a staging modality on which there is no clear consensus. Opinions range from recommending its use in all patients prior to laparotomy to recommending not performing it at all. Overall, I believe that staging laparoscopy is a useful tool to diagnose advanced disease not detected by imaging or EUS studies in a selected sub-group of patients at high risk of advanced disease including (a) large (> 3cm) primary tumors (b) tumors of the neck, body or tail of pancreas (c) high CA 19-9, weight loss, hypoalbuminemia (d) and in patients with equivocal findings of metastatic disease upon imaging.[8] Our patient clearly had resectable disease, per intra-operative staging and did not meet any of the criteria above. She would not have benefited from either additional scans or laparoscopy.
