A Case of Pancreatic Adenosquamous Carcinoma Obstructing the Common Bile and Pancreatic Ducts, Duodenum, and Gastric Outlet

Abstract

A 76-year old Caucasian female was admitted for a 6 week-history of nausea, vomiting, abdominal pain, and a 20-pound weight loss. No tobacco or alcohol consumption and no previous history of pancreatic disease or familial pancreatic cancer were reported. Vital signs were within normal. Physical exam was notable for epigastric tenderness. Serum lipase, alkaline phosphatase, and cancer antigen 19-9 were elevated. Other routine laboratory test results were non-contributory. Contrast-enhanced computed tomography (CECT) of the abdomen and pelvis showed a 2.7 by 3.5 cm heterogeneously enhancing mass in the head of the pancreas causing obstruction of the common bile duct (CBD) and stomach and nearly occluding the portal vein at the confluence. EUS identified an irregular, hypo-echoic mass in the pancreatic head measuring 40 by 35 mm in maximal cross-sectional diameter with intact interference between the mass and the adjacent structures suggesting lack of invasion. Several peritumoral malignant, appearing lymph nodes were also identified by EUS. The pancreatic duct and CBD were dilated at 4 and 20 mm in diameter respectively. EUS-FNA biopsy was performed using a 22-gauge Wilson-Cook EchoTip biopsy needle via a transduodenal approach. Cytological and immunohistochemistry (IHC) staining showed the presence of two components of cells; adenocarcinoma and squamous carcinoma. Based on clinical exam, CECT, EUS-FNA biopsy, and IHC staining, a diagnosis of locoregional PASC was made. Pancreatic cancer is the fourth leading cause of cancer deaths in the USA. PASC is rare, more aggressive, and makes only 0.5 % of pancreatic cancer. This is a rare case of PASC obstructing multiple gastrointestinal and hepatobiliary sites and presenting without jaundice or significant elevation in bilirubin. The combination of CECT with EUS seems to produce the highest accuracy for staging and diagnosing pancreatic neoplasm and for assessing the respectability of the tumor. Cytology and IHC staining of collected EUS-FNA biopsies showed a dual population of malignant glandular cells with intracellular mucin production as well as pleomorphic squamous cells making greater than 30 % of malignant cells; meeting histological criteria of PASC. The application of the CECT/EUS-FNA modality helped characterize the tumor resectability in our patient. In a locoregional PASC, tumor resectability is the strongest independent predictor of to survival. The patient underwent surgical tumor resection successfully and will be followed up.Figure 1Figure 2Figure 3