Serous Cystadenoma of the Pancreas: Understanding Your Pathology Report

by Jason Wasserman MD PhD FRCPC
June 16, 2026

A serous cystadenoma is a benign (non-cancerous) tumor of the pancreas. It is made up of many small, fluid-filled spaces called cysts, lined by cells that contain a natural sugar called glycogen. Most serous cystadenomas grow slowly, cause no symptoms, and are found by chance during imaging done for another reason. A serous cystadenoma is one of the few pancreatic tumors that is almost always harmless.

This article will help you understand the findings in your pathology report, what each term means, and why it matters for your care.

What causes serous cystadenoma?

The exact cause is not known. Most serous cystadenomas occur on their own, without an inherited cause. In some cases, they are linked to an inherited condition called von Hippel-Lindau syndrome, which increases the risk of several types of tumors. Most people with a serous cystadenoma do not have this condition, but if it is suspected, your doctor may suggest genetic counseling, which can also help relatives understand their own risk.

Where in the pancreas are serous cystadenomas found?

Serous cystadenomas can develop anywhere in the pancreas, but most are found in the body or tail. In rare cases, more than one tumor is present, especially in people with von Hippel-Lindau syndrome.

What are the symptoms of serous cystadenoma?

Most people with a serous cystadenoma have no symptoms, and the tumor is found by chance during an imaging test such as a CT scan or MRI. When symptoms do occur, they are usually caused by the tumor pressing on nearby organs and may include:

Abdominal or back pain.
Nausea or vomiting.
Feeling full quickly or bloated.
Weight loss.
Diabetes (in rare cases).

Rarely, a tumor in the head of the pancreas can block the bile duct, leading to jaundice (yellowing of the skin and eyes).

How is the diagnosis made?

Doctors often suspect a serous cystadenoma based on imaging studies that show a cystic tumor in the pancreas, since these tumors frequently have a characteristic appearance on CT or MRI. Even so, it can be difficult to tell a serous cystadenoma apart from other pancreatic cysts before surgery. A sample of fluid from the cyst may be taken during an endoscopic ultrasound and tested for specific proteins and genes; serous cystadenomas typically have low levels of the protein CEA, which helps distinguish them from mucinous cystic neoplasms and intraductal papillary mucinous neoplasms. A definitive diagnosis is made when a pathologist examines the tumor under the microscope.

Under the microscope, the tumor consists of small cysts lined by a single layer of uniform, cube-shaped cells. These cells have clear or pale cytoplasm because they contain glycogen. The nuclei (the part of the cell that holds DNA) are small and round, and there are no signs of cancer, such as mitotic figures (dividing cells) or nuclear atypia (irregularly shaped nuclei). A scar is often seen in the center of the tumor, and small blood vessels (capillaries) may be present between the cysts.

Are there different types of serous cystadenoma?

Yes. Pathologists recognize several patterns of serous cystadenoma:

Microcystic — The most common type. It is composed of many tiny cysts and often has a scar at the center.
Macrocystic (oligocystic) — This type has fewer but larger cysts and can resemble other pancreatic cysts.
Solid serous adenoma — A rare type that has no cysts and looks solid under the microscope.
Diffuse serous cystadenoma — The tumor replaces most or all of the pancreas and is often seen in people with von Hippel-Lindau syndrome.
Mixed serous-neuroendocrine neoplasm — Rarely, a serous cystadenoma is found together with a neuroendocrine tumor in the same pancreas.

These patterns can affect how the tumor looks on imaging, but they do not change the fact that a serous cystadenoma is benign.

What happens after the diagnosis?

Because a serous cystadenoma is benign, the outlook is excellent. Most tumors do not grow or cause symptoms and do not need to be removed. When the diagnosis is confident, and the tumor is small and causing no problems, the treatment team often recommends watching it with imaging from time to time rather than removing it.

Surgery is usually considered only when the tumor is large, is causing symptoms, or cannot be confidently distinguished from another type of pancreatic cyst before surgery. When surgery is performed, complete removal is curative, and the tumor coming back afterward is very rare. Because it is not always possible to be certain of the diagnosis from a small fluid or tissue sample alone, removing the tumor sometimes serves both to confirm the diagnosis and to treat it. If von Hippel-Lindau syndrome is suspected, your doctor may suggest genetic counseling for you and your family.

Questions to ask your doctor

How confident is the diagnosis of serous cystadenoma based on my tests?
Was the entire tumor removed, or will it be monitored over time?
If the tumor was not removed, how often should I have follow-up imaging?
Could this tumor be confused with another type of pancreatic cyst?
Does this tumor suggest I might have an inherited condition such as von Hippel-Lindau syndrome?
Should I consider genetic counseling for myself or my family?
What symptoms should I watch for that might mean the tumor is causing a problem?
Do I need any further treatment?