Peter, a 67-year-old patient, presents to the GP with jaundice and a non-tender palpable mass in the right upper quadrant. The doctor suspects malignancy.

From the clinical findings, which location is the most likely source of cancer?

Options:
explanation: This is not the correct answer. The body of the pancreas is in the midline of the human body, posterior to the stomach and the left of the superior mesenteric vessels. Given its anatomical relations, a tumour in this part of the pancreas is more likely to cause abdominal and/or back pain and would not result in a gradual painless distension of the gall bladder over time. As such, it is not consistent with the presentation in the question which describes the Courvoisier's sign.
name: Body of the pancreas
label: e
answer: no
explanation: This is the correct answer. A painlessly enlarged gall bladder resulting in a palpable mass in the right upper quadrant with associated jaundice is known as Courvoisier's sign. This is unlikely to be caused by cholelithiasis and normally due to a chronic obstruction, such as a pancreatic head cancer or a cholangiocarcinoma, which causes raised biliary back pressure and results in gradual distension of the gall bladder over time without pain as there is no acute damage. This is distinct from a palpable gall bladder with no jaundice, seen in Mirizzi's syndrome, and non palpable painless gall bladder with jaundice, seen in shrunken fibrotic and calcified gall bladder secondary to repeated acute inflammation ("porcelain gall bladder).
name: Head of the pancreas
label: a
answer: yes
explanation: This is not the correct answer. The neck of the pancreas is located superior to the superior mesenteric vessels. Given its anatomical relation, a tumour in this part of the pancreas would not result in a gradual distension of the gall bladder over time, as such, it is not consistent with the presentation in the question which describes the Courvoisier's sign.
name: Neck of the pancreas
label: d
answer: no
explanation: This is not the correct answer. The pancreatic tail lies within close proximity to the spleen hilum and is contained within the splenorenal ligament with the splenic vessels. It is also the only part of the pancreas that is not retroperitoneal, therefore intraperitoneal. Abdominal pain and weight loss are more likely with pancreatic tail cancer. As such, a tumour in this part of the pancreas would not result in a gradual painless distension of the gall bladder over time and is not consistent with the presentation in the question which describes the Courvoisier's sign.
name: Tail of pancreas
label: b
answer: no
explanation: This is not the correct answer. The uncinate process of the pancreas is a projection arising from the inferior aspect of the pancreatic head and lies posterior to the superior mesenteric vessels and close in proximity to the third part of the duodenum. A tumour here is less likely to cause jaundice and more likely to obstruct the third part of the duodenum. Given its anatomical relation, a tumour in this part of the pancreas would not result in a gradual distension of the gall bladder over time without pain, as such, it is not consistent with the presentation in the question which describes the Courvoisier's sign.
name: Uncinate process
label: c
answer: no

Correct answer: a