There are many types of pancreas tumors, and correctly identifying each one is important to determine the proper treatment.

What are Tumors?

The terms "tumor" and "cancer" are sometimes used interchangeably, which can be misleading. A tumor is not necessarily a cancer. The word tumor simply refers to a mass. For example, a collection of fluid would meet the definition of a tumor. A cancer is a particularly threatening type of tumor. It is helpful to keep these distinctions clear when discussing a possible cancer diagnosis.

The word "cancer" is derived from the Latin word for crab because cancers are often very irregularly shaped, and because, like a crab, they "grab on and don't let go." Cancer specifically refers to a new growth which has the ability to invade surrounding tissues, metastasize (spread to other organs) and which may eventually lead to the patient's death if untreated.

Term Definition
Tumor (Neoplasm) The term "tumor" is a commonly used term for a neoplasm. The word tumor simply means a mass. Tumor is therefore a general term that can refer to benign or malignant growths.
Benign Tumor Benign tumors are non-malignant/non-cancerous tumors. A benign tumor is usually localized, and does not spread to other parts of the body. Many benign tumors don't need treatment, and the majority of those that do are curable. However, if left untreated, some benign tumors can grow large and lead to serious complications because of their size. Benign tumors can also mimic malignant tumors, and so for this reason are sometimes treated.
Malignant Tumor (Cancer) Malignant tumors are cancerous growths. They are often resistant to treatment, may spread to other parts of the body and they sometimes recur after they were removed.
Primary Cancer A primary pancreatic cancers arose in the pancreas itself.
Metastatic Cancer Metastatic cancers arise in one organ and only later spread to other organs. A cancer is considered primary to the organ from which it arose; a cancer that arises in the pancreas and spreads to the liver is considered a pancreatic, not liver, cancer.

Dr. Hruban explains the different types of tumors & pancreatic tumors

Types of Pancreas Tumors

Cancer of the pancreas is not one disease. As many as ten different tumor types have been lumped under the umbrella term "cancer of the pancreas", classified as exocrine or endocrine tumors. Each of these tumors has a different appearance when examined with a microscope, some require different treatments, and each carries its own unique prognosis. An accurate classification of the tumor type is crucial for proper treatment.

Adenocarcinoma of the pancreas   

This is the form of cancer that most people are talking about when they refer to "cancer of the pancreas." These neoplasms account for >75% of all pancreas cancers. Adenocarcinomas belong to the class of cancers known as "exocrine tumors of the pancreas."

Neuroendocrine Tumors   

Neuroendocrine tumors are far less common than exocrine neoplasms. Neuroendocrine neoplasms (also known as "endocrine" or "islet cell" tumors) account for only 1-5% of pancreatic cancers.

It is very important that neuroendocrine neoplasms be distinguished from nonendocrine because the symptoms and the treatments for the two neoplasms are very different.

Read about Neuroendocrine Tumors

Cystic Tumors, including IPMNs   

Cystic tumors are a special type of exocrine tumors. They are united by the formation of fluid-filled cavities. They are common and although most are harmless, a small fraction can be cancerous.

Learn about IPMNs

Under the Microscope: Pancreas Tumors

Pathologists are the doctors who identify, diagnose and classify a cancer by examining the patient's biopsied tissue samples under a microscope. To make the cells visible the tissue sample slides are stained with various dyes. Pathologists identify abnormalities by changes in the size, shape or arrangement of cells.

Use the slider below to see adenocarcinomas and other types of exocrine pancreas tumors as they look under a microscope.

  • Adenocarcinoma

    Adenocarcinomas (most common)

    This is a gland-forming (it makes tubes) cancer. They often invade blood vessels and wrap around nerves.

  • Acinar cell carcinoma

    Acinar Cell Carcinomas

    The cancer cells join to form circles with small spaces (acini), and the tumor cells look like normal acinar cells of the pancreas. Some acinar carcinomas release digestive enzymes into the circulation, causing the clinical syndrome of "fat necrosis."

  • Adenosquamous

    Adenosquamous Carcinomas

    This is a very aggressive form of cancer. The cancer cells (right side of the image) have two directions of differentiation. Cancer cells form glands ("adeno"), and cancer cells form flat sheets ("squamous").

  • Colloid

    Colloid Carcinomas

    Colloid cancers tend to be less aggressive. They often arise in association with an IPMN precursor lesion. The neoplastic cells are "floating" in pools of mucin.

  • Hepatoid

    Hepatoid Carcinomas

    Hepatoid carcinomas are extremely rare. The tumor cells look like normal liver cells under the microscope.

  • IPMN

    Intraductal Papillary Mucinous Neoplasms (IPMNs)

    Neoplasms that are characterized by ductal dilation, intraductal papillary growth, and thick mucus secretion.

  • Mucinous cystic neoplasm

    Mucinous Cystic Neoplasms

    These cyst-forming tumors arise in the tail of the pancreas, and have a distinctive "ovarian-type stroma." (bottom third of the image) Some can, over time, progress to an invasive cancer.

  • Pancreatic intraepithelial neoplasia

    Pancreatic Intraepithelial Neoplasia

    These small microscopic lesions are common, particularly as we age. They arise in microscopic ducts, and a very small fraction, over time, progress to invasive cancer.

  • Pancreatoblastoma

    Pancreatoblastomas

    These rare tumors often arise in children. The tumor cells have several directions of differentiation. Some cells have acinar differentiation, and the defining feature is the presence of "squamoid nests."

  • Serous cystadenoma

    Serous Cystadenomas

    This benign tumor forms spaces (cysts), giving the tumor a "sponge-like" appearance. The tumor cells are cube shaped and have clear cytoplasm.

  • Signet ring cell carcinoma

    Signet Ring Cell Carcinoma

    This tumor type is rare in the pancreas. The tumor cells look like "signet rings," rings with large seals. Hence the name.

  • Solid pseudopapillary neoplasm

    Solid-Pseudopapillary Neoplasm

    This tumor is more common in women. The tumor cells surround thin delicate blood vessels. Other common features include hyaline (pink) globules.

  • Undifferentiated

    Undifferentiated Carcinomas

    This is a very aggressive form of cancer. The tumor cells look very primitive, and don't look like any normal cell in the pancreas.

  • Undifferentiated carcinoma with osteoclast like giant cells

    Undifferentiated Carcinoma with Osteoclast-like Giant Cells

    This tumor is composed of two cell types. The cancerous cells are the big cells on the right of this image. The large osteoclast-like cells (center of the image) contain lots of nuclei and are the body's non-tumorous cells reacting to the cancer.

Adenocarcinomas (most common)

This is a gland-forming (it makes tubes) cancer. They often invade blood vessels and wrap around nerves.


Acinar Cell Carcinomas

The cancer cells join to form circles with small spaces (acini), and the tumor cells look like normal acinar cells of the pancreas. Some acinar carcinomas release digestive enzymes into the circulation, causing the clinical syndrome of "fat necrosis."


Adenosquamous Carcinomas

This is a very aggressive form of cancer. The cancer cells (right side of the image) have two directions of differentiation. Cancer cells form glands ("adeno"), and cancer cells form flat sheets ("squamous").


Colloid Carcinomas

Colloid cancers tend to be less aggressive. They often arise in association with an IPMN precursor lesion. The neoplastic cells are "floating" in pools of mucin.


Hepatoid Carcinomas

Hepatoid carcinomas are extremely rare. The tumor cells look like normal liver cells under the microscope.


Intraductal Papillary Mucinous Neoplasms (IPMNs)

Neoplasms that are characterized by ductal dilation, intraductal papillary growth, and thick mucus secretion.


Mucinous Cystic Neoplasms

These cyst-forming tumors arise in the tail of the pancreas, and have a distinctive "ovarian-type stroma." (bottom third of the image) Some can, over time, progress to an invasive cancer.


Pancreatic Intraepithelial Neoplasia

These small microscopic lesions are common, particularly as we age. They arise in microscopic ducts, and a very small fraction, over time, progress to invasive cancer.


Pancreatoblastomas

These rare tumors often arise in children. The tumor cells have several directions of differentiation. Some cells have acinar differentiation, and the defining feature is the presence of "squamoid nests."


Serous Cystadenomas

This benign tumor forms spaces (cysts), giving the tumor a "sponge-like" appearance. The tumor cells are cube shaped and have clear cytoplasm.


Signet Ring Cell Carcinoma

This tumor type is rare in the pancreas. The tumor cells look like "signet rings," rings with large seals. Hence the name.


Solid-Pseudopapillary Neoplasm

This tumor is more common in women. The tumor cells surround thin delicate blood vessels. Other common features include hyaline (pink) globules.


Undifferentiated Carcinomas

This is a very aggressive form of cancer. The tumor cells look very primitive, and don't look like any normal cell in the pancreas.


Undifferentiated Carcinoma with Osteoclast-like Giant Cells

This tumor is composed of two cell types. The cancerous cells are the big cells on the right of this image. The large osteoclast-like cells (center of the image) contain lots of nuclei and are the body's non-tumorous cells reacting to the cancer.


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