It’s been reported (including on this blog) that Apple founder Steve Jobs died of pancreatic cancer, but some experts and readers point out that he did not have the common form. He had a neuroendocrine tumor.

Dr. Mansur Shomali, from Union Memorial Hospital’s Diabetes & Endocrine Center, explains that the pancreas is divided into two parts: the “exocrine” pancreas and the “endocrine” pancreas. The common form of pancreatic cancer arises from the exocrine pancreas, the part that makes digestive enzymes.

Job’s reported cancer came from the endocrine pancreas, which is made cells that produce hormones like insulin. They cluster and are called islets. Sometimes they produce tumors, which aren’t always cancerous.

Shomali said they are called neuroendocrine because they originate from neurologic tissue during embryologic development.

He said he’s seen only one patient in the last 12 months with such a tumor.

And while he did not treat Jobs and doesn’t know the detail of his case, he said when caught early, the tumors are treatable. While some tumors are very aggressive, many are benign and don’t spread.

The National Cancer Institute reports that 80 percent of patients survive the first year and 22 percent survive 10 years – many times the survival rates for more common pancreatic cancer.

It’s unclear what sort of treatment Jobs had and why, for example, he had a liver transplant – Shomali said he’s not had a patient that needed one.

For more information, go to http://www.cancer.gov/cancertopics/pdq/treatment/isletcell/Patient.