A Rare Case Of Bladder Cancer Metastasis To Pancreas
Bladder cancer is newly diagnosed in roughly 80,000 people annually while causing death in 17,000 people with urothelial carcinoma being the most prominent subtype. (1) Bladder cancer usually metastasizes to lymph node, bone, and liver but metastasis to pancreas is very rare. We present a rare case of metastatic bladder carcinoma to Pancreas which was successfully managed with biliary stent placement.
Our patient is a 77 years old female with a past medical history of hypertension and dyslipidemia who was diagnosed with T2 N0 high grade muscle invasive urothelial carcinoma status post transurethral resection of bladder tumour. During her oncology appointment she complained of nausea and vomiting with suprapubic pain. For the pain she was taking almost 4-5 grams of acetaminophen per day. She was suspected to have acetaminophen toxicity and was sent to the emergency room. Her vitals signs were stable and she was afebrile. Labs showed ALT: 849 U/L, AST: 503 U/L, ALP: 1116 U/L, Total Bilirubin: 4.4 mg/dl, Direct Bilirubin: 3.8 md/dl, Acetaminophen: < 2 ug/ml, Lipase: 376 U/L, WBC: 8.5 K/mm3.
CT of the abdomen showed severe intrahepatic biliary ductal dilatation. The common bile duct was dilated up to 1.1 cm, gallbladder was dilated up to 4.4cm with small amount of pericholecystic fluid and adjacent fat stranding with mild wall thickening. There was mild fat stranding and oedema in the pancreaticoduodenal groove and around the pancreatic head with atrophy of the pancreatic tail.
MRCP that day showed moderate to severe intra and extrahepatic biliary ductal dilatation. The distal common duct tapers significantly within the pancreatic head with no evidence of cholelithiasis or choledocholithiasis. The pancreatic body and tail parenchyma is atrophic with main ductal dilatation. The pancreatic head parenchyma is relatively preserved. No main pancreatic ductal dilatation within the pancreatic head and neck.
Her tumour makers showed significant elevation in CA19-9 (4163 u/ml). She was transferred to a tertiary centre for EUS/FNA. An upper endoscopy was done and duodenal obstruction was treated with a metallic stent placement following which EUS evaluation was performed. EUS revealed a pancreatic head lesion that was causing CBD and main pancreatic duct narrowing, FNA of pancreatic head lesion was preformed and uncovered metallic stents were placed in CBD and main pancreatic duct. Immunohistology of the pancreatic head lesion came back positive for GATA-3 and p63 which was consistent with the diagnosis of metastatic carcinoma of the bladder. After placement of the biliary stents her ALT/AST/ALP/Tbili trended down to normal. She was eventually discharged with normalization of her liver related tests.
Pancreatic metastasis is an uncommon site for bladder cancers. Most common sites of metastasis for bladder cancers are lymph node, bone, urinary tract, lung and liver but the metastasis to pancreas is very rare. (2) There have been very few cases regarding metastasis of urothelial cancer to pancreas with majority of them being diagnosed post-autopsy. (3-5) Our patient was diagnosed with muscle invasive bladder cancer and underwent transurethral resection on 2/13/19 and was diagnosed 7 months later with metastatic bladder carcinoma to pancreas. Muscle invasive bladder cancer typically treated with radical cystectomy and neoadjuvant chemotherapy as compared to non-muscle invasive disease which is treated with transurethral resection and intravesical chemotherapy. Our patient developed metastasis despite receiving cisplatin based neoadjuvant chemotherapy which has shown to improve survival.(6) Metastasis to pancreas is rare with most common primary sites of tumour being Lung, GI tract and Kidney.(5) In our patient it caused compression of the CBD and main pancreatic duct and was successfully treated with the biliary stent placement and patient discharged home.
This is the one of the few cases which reports metastasis of bladder carcinoma to pancreas. This case should make us consider bladder tumour metastasis as one of the differentials in a patient with pancreatic head mass with a history of a bladder cancer.