What is a stoma?

A stoma is a surgically created opening that connects an internal organ to the outside of the body. It allows air, fluid, or waste to leave the body in a new way when the normal pathway is blocked, damaged, or removed. A stoma may be temporary or permanent, depending on the medical condition.

When a stoma is present, your pathologist may receive a sample of tissue from the area if surgery is performed to repair, revise, or close the stoma, or if your doctor is concerned about irritation, infection, or abnormal changes in the surrounding skin or organ tissue.

What does stoma tissue look like under the microscope?

Under the microscope, a stoma usually contains a combination of:

• Skin, which forms the outer border of the opening.

• Tissue from the connected organ, such as the bowel, trachea, or urinary tract lining.

Because a stoma is exposed to the outside environment, the tissue may show signs of irritation, inflammation, or healing. Your pathologist examines this tissue to look for infection, scarring, abnormal growths, or other changes that may require treatment.

Where on the body can a stoma be created?

Stomas can be created in different parts of the body depending on the medical condition being treated. Some of the most common types include:

Tracheostomy (neck stoma)

A tracheostomy is a stoma created in the neck that connects the windpipe (trachea) to the skin.
A tracheostomy allows air to enter and leave the lungs when breathing through the mouth or nose is not possible. This may be necessary when the upper airway is blocked or when long-term mechanical ventilation is required.

Ostomy (abdominal stoma)

Several types of stomas can be created in the abdomen, depending on which part of the digestive or urinary system needs support.

Common examples include:

• Ileostomy: Connects the small intestine (ileum) to the skin so that waste can leave the body when the colon is blocked or removed.

• Colostomy: Connects a part of the large intestine (colon) to the skin to allow stool to pass.

• Urostomy: Connects the urinary system to the skin, allowing urine to drain when the bladder is removed or cannot function normally.

These stomas help the body eliminate waste safely when the usual pathway cannot be used.

Why might tissue from a stoma be sent to a pathologist?

Stoma-related tissue may be examined for several reasons:

• The stoma is being repaired or revised surgically.

• The stoma is being closed because the normal pathway has been restored.

• The tissue around the stoma appears inflamed, ulcerated, or abnormal during a medical exam.

• There is concern for infection, granulation tissue (overgrowth of healing tissue), or, very rarely, tumour development.

Pathologists examine the tissue to determine the cause of any problems and to help guide further treatment if needed.

What conditions can affect a stoma?

Some common issues that may occur around a stoma include:

• Irritation or inflammation caused by exposure to stool, urine, or moisture.

• Granulation tissue, which is extra healing tissue that may bleed easily.

• Infection of the skin or deeper tissue.

• Stricture, which is narrowing of the stoma opening.

• Parastomal hernia, a bulge near the stoma caused by weakening of the abdominal wall.

• Rare tumours, which can develop in long-standing stomas, especially in people with certain medical conditions.

Your pathology report will describe the changes seen in the tissue and help your doctor decide whether treatment is necessary.

Questions to ask your doctor

• Why was tissue taken from my stoma?

• What changes did the pathologist see in the tissue?

• Are the findings related to irritation, infection, or another condition?

• Do I need treatment, additional testing, or follow-up?

• If my stoma is temporary, when can it be closed?

• If the stoma is permanent, how can I best care for the surrounding skin?