Contributed by Humberto Trejo Bittar, MD. Sheldon Bastacky, MD and Aatur D. Singhi, MD, PhD.
75 year-old male with past medical history significant for prostate cancer status-post radical prostatectomy 15 years ago, who presented with complaints of approximately diarrhea, dark urine, light stools, pruritus and 15 lb weight loss over the last month. He also admits to fevers and chills. He had a few episodes of abdominal cramps over the last couple weeks but denied persistent abdominal pain, nausea or vomiting. Laboratory tests demonstrated the following values: total bilirubin 10.3 mg/dl, direct bilirubin 6.9 mg/dl, ALT 121 IU/L, AST 64 IU/L, alkaline phosphatase 435 IU/L, amylase 57 IU/L and lipase 238 U/L. A CT scan of the abdomen and pelvis with contrast revealed a vague area of architectural distortion and perhaps diminished enhancement within the pancreatic head that measured between 1.5 to 2.0 cm. In addition, multiple clustered, slightly enlarged celiac-gastrohepatic ligament lymph nodes were identified together with a conglomerate peripancreatic nodal mass measures approximately 3.0 x 2.4 cm. Biliary dilatation with possible distal common bile duct stricture and dilatation of the gallbladder were also identified.
ENDOSCOPIC RETROGRADE CHOLANGIOPANCREATOGRAPHY (ERCP) AND ENDOSCOPIC ULTRASOUND (EUS)
An ERCP revealed small major papilla, pancreatic duct stricture, severe biliary stricture, and moderately dilated middle and third main bile duct. A mucosal biopsy of the bile duct was submitted to surgical pathology. An EUS showed a 2.1 cm ill-defined solid hypoechoic mass in the pancreatic head (Figure 1), irregularly contoured and ectatic pancreatic duct (up to 4 mm in diameter), few abnormal peripancreatic head regional lymphs, and suggestion of a stricture in the lower third of the main bile duct and dilation in the gallbladder. Fine needle aspiration of the pancreatic head mass and peripancreatic lymph nodes was performed.
Cytological preparations and cell block from the pancreatic head mass and enlarged lymph nodes consisted of hypercellular sheets and clusters of pleomorphic and cohesive atypical cells with abundant granular cytoplasm, and an enlarged nucleus with a prominent eosinophilic nucleolus. Occasional architectural, rosette or acinar formation was also seen. (Figures 2, 3, 4 and 5).
The bile duct biopsy was mostly crushed and consisted of a strips of biliary-type epithelium, admixed blood and few cluster and single cells with marked cytologic atypia, characterized by a scant cytoplasm and a hyperchromatic nucleus. Although crushed, these histologic findings were highly concerning for a poorly-differentiated neoplasm (Figures 6, 7, 8, 9, 10 and11).
Immunohistochemical stains on the bile duct biopsy demonstrated the atypical cells were positive for cytokeratin AE1/AE3 (Figure 12), CAM 5.2 (Figure 13), CK19 (Figure 14, note the weakly positive neoplastic cells and strongly positive biliary-type epithelium), and Nkx3.1 (Figures 15 and 16, note the diffuse nuclear positivity of the neoplastic cells and the negative staining of the biliary-type epithelium); while negative for synaptophysin, S-100 protein, tyrosinase, trypsin, CD45, CD43, PSA, PSMA and P501S.
Immunohistochemical stains performed on the cell block preparations from the pancreatic head fine needle aspirate showed immunohistochemical positivity for CK19 (Figure 17), Ber-EP4 (Figure 18), monoclonal CEA (focal), PSA (focal, Figure 19), androgen receptor (Figure 20) and Nkx3.1 (Figure 21); while negative for synaptophysin and trypsin.