The commonest pancreatic tumour is –
**Core Concept**
Pancreatic tumors are a heterogeneous group of neoplasms with varying clinical behavior and prognosis. The most common type of pancreatic tumor can be distinguished based on its histological characteristics and clinical presentation.
**Why the Correct Answer is Right**
The most common pancreatic tumor is the pancreatic neuroendocrine tumor (PNET), also known as an islet cell tumor. These tumors arise from the pancreatic islets and are often functional, producing excess hormones such as gastrin, insulin, or vasoactive intestinal peptide (VIP). PNETs can be benign or malignant and may present with symptoms related to hormone hypersecretion or as an incidentally discovered mass.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because PNETs are more common than pancreatic adenocarcinomas, which are often cited as the most common type of pancreatic cancer. However, PNETs are still a minority compared to adenocarcinomas.
**Option B:** This option is incorrect because pancreatic lymphoma is a rare type of pancreatic tumor, accounting for less than 5% of all pancreatic malignancies.
**Option C:** This option is incorrect because pancreatic metastases are more common than primary pancreatic tumors, but they are not the most common type of pancreatic tumor.
**Clinical Pearl / High-Yield Fact**
Pancreatic neuroendocrine tumors can produce a wide range of clinical syndromes due to hormone hypersecretion, making them a classic example of a tumor with multiple endocrine manifestations.
**Correct Answer: C. Pancreatic neuroendocrine tumor (PNET)**