Oncocytic adrenal cortical carcinoma is a rare cancer that starts in the adrenal cortex, the outer layer of the adrenal gland. It is a subtype of adrenal cortical carcinoma. Your report may use the name oncocytic adrenocortical carcinoma, which means the same thing.
The word oncocytic describes how the tumor cells look under the microscope. They are large and bright pink because they are packed with mitochondria, the parts of a cell that make energy. A tumor is called oncocytic when more than 90% of its cells look this way.
As a group, oncocytic adrenal cortical carcinomas tend to grow more slowly than the usual type of adrenal cortical carcinoma. They can still come back or spread, so your report findings matter.
This article explains how oncocytic adrenal cortical carcinoma is diagnosed and what the findings in your pathology report mean. It also notes which findings appear in every report and which are optional.
Not every oncocytic tumor of the adrenal gland is a cancer. Pathologists sort these tumors into three groups, and the names are easy to confuse:
The group matters because each one has a different outlook and a different follow-up plan.
Oncocytic adrenal cortical carcinoma most often affects adults in their 40s and 50s, although it can develop at any age. It affects men and women about equally.
In most people, the cause of oncocytic adrenal cortical carcinoma is not known. A small number of adrenal cortical carcinomas develop in people born with a condition that raises the risk of cancer, such as Li-Fraumeni syndrome or Lynch syndrome. For this reason, your doctor may ask about cancers in your family.
Most oncocytic adrenal cortical carcinomas do not make extra hormones. These tumors often cause no symptoms until they are large. They can then cause abdominal or side pain, or a feeling of fullness. Some are found by accident on a scan done for another reason.
About one in three makes extra hormones. Extra cortisol is the most common and causes Cushing syndrome. Symptoms include abdominal weight gain, a rounded face, muscle weakness, easy bruising, and high blood pressure.
The diagnosis of oncocytic adrenal cortical carcinoma is usually made after the tumor is removed and examined under the microscope by a pathologist. A needle biopsy is usually avoided when an adrenal cancer is suspected, because it can spread tumor cells along the needle path.
Before surgery, blood and urine tests show whether the tumor is making extra hormones. Our article on adrenal hormone tests explains these results. A CT or MRI scan shows the size of the tumor.
Under the microscope, the pathologist first confirms that the tumor is oncocytic. Next, the pathologist decides which of the three groups it belongs to. To do this, the pathologist looks for a specific set of features, described in the section on the Lin-Weiss-Bisceglia criteria below.
Once oncocytic adrenal cortical carcinoma is confirmed, scans of the chest and abdomen look for spread. The special stains sometimes used to support the diagnosis are described in the next section.
Immunohistochemistry uses antibodies to show which proteins tumor cells make. For oncocytic adrenal cortical carcinoma, it helps confirm that the tumor started in the adrenal cortex. This matters because oncocytic tumors from other organs, such as the kidney, can look similar.
Laboratories use different stains, and no fixed set is required. Your report may include some of the following:
The stains on your report may be different from these, and some reports list very few. These stains show where the tumor started. They do not show how it will behave.
The Lin-Weiss-Bisceglia criteria are the features pathologists use to decide whether an oncocytic adrenal tumor is a cancer. The usual scoring system for adrenal tumors, the Weiss score, does not work well for oncocytic tumors. Your report may name the Lin-Weiss-Bisceglia system, or it may simply list the features that were found.
The features are divided into major and minor criteria. Finding even one major criterion makes the diagnosis of oncocytic adrenal cortical carcinoma.
Minor criteria are less worrying. A tumor with only minor criteria is called an oncocytic tumor of uncertain malignant potential. In a carcinoma, they may be listed alongside the major criteria.
This system does not give a score. The number of criteria does not tell you how advanced the cancer is. The stage, grade, and Ki-67 index are better guides to the outlook.
The grade of oncocytic adrenal cortical carcinoma describes how quickly the tumor cells are dividing. The pathologist counts the mitotic figures in a set area of the tumor. This number is the mitotic count, and it should be in every report.
Most oncocytic adrenal cortical carcinomas are low grade. High-grade tumors tend to grow faster and are more likely to come back or spread. Your team uses the grade to decide on treatment after surgery.
Ki-67 is a protein found in cells that are getting ready to divide. The Ki-67 index is the percentage of tumor cells that contain it. It should be in every report for oncocytic adrenal cortical carcinoma. Some reports call the test MIB-1.
A higher Ki-67 index is linked to a higher chance of the cancer coming back after surgery. No cut-off is agreed on, but 10% or less is often treated as lower risk.
Some pathologists use additional tools to support the diagnosis of oncocytic adrenal cortical carcinoma. These are optional, and many reports do not include them.
Your report will give the size of the oncocytic adrenal cortical carcinoma, measured across its widest point in centimeters (cm). These tumors are often large when they are found. Your report will also describe tumor extension, which means how far the tumor has grown. Both are used to set the tumor stage.
A margin is the edge of tissue the surgeon cuts when removing the tumor. The pathologist examines the margins to see whether any tumor cells are present at the cut edge.
Your report will also say whether the tumor arrived in one piece. Terms such as “capsule disrupted” or “fragmented” mean the tumor surface was opened or the tumor was in pieces. This raises the chance of the cancer coming back in the same area.
The pathologic stage describes the size of the oncocytic adrenal cortical carcinoma and whether it has spread. It is assigned after the tumor is removed, using the AJCC staging system, 8th edition. The same system applies to all adrenal cortical carcinomas. The tumor stage (pT) is:
Lymph nodes are not removed in every operation for this cancer. If they were, the report states how many were examined and how many were positive for cancer. The nodal stage is pN0 when none contain cancer and pN1 when at least one does. If no lymph nodes were removed, your report may say pNX or that the nodal stage was not assigned.
Your doctors combine the pathologic stage with your scans to give an overall stage from I to IV. Stages I and II are tumors confined to the adrenal gland. Stage III means growth outside the gland or cancer in nearby lymph nodes. Stage IV means spread to distant organs, most often the liver or lungs.
The outlook for oncocytic adrenal cortical carcinoma is better, on average, than for the usual type of adrenal cortical carcinoma. Most oncocytic tumors are still confined to the adrenal gland when they are found, and they are less likely to spread.
The outlook depends mostly on the stage and on whether all of the tumor could be removed. When the tumor is confined to the adrenal gland and completely removed, about 9 in 10 people are alive five years later. When it has grown outside the gland or spread, about 4 in 10 are alive.
This cancer is rare, so these numbers come from small groups of people. They cannot tell you what will happen to you.
Features in your report that are linked to a higher chance of the cancer coming back include:
Oncocytic adrenal cortical carcinoma can come back years after surgery, which is why follow-up continues for a long time.
A team at a center experienced with adrenal tumors usually plans the care for oncocytic adrenal cortical carcinoma. Your team uses the stage, margins, grade, and Ki-67 index to decide which options to discuss with you.
Because oncocytic tumors are rare, treatment follows the same approach used for other adrenal cortical carcinomas. The FDA and Health Canada have approved mitotane for adrenal cortical carcinoma that cannot be removed by surgery. Expert guidelines support its use after surgery.