Erosive Esophagitis: Understanding Your Pathology Report

By Jason Wasserman MD PhD FRCPC
July 29, 2026

Erosive esophagitis means that the lining of the esophagus, the muscular tube that carries food and liquid from the mouth to the stomach, is inflamed and has been worn away in places. The esophagus is lined by squamous cells, which form a protective surface layer called the epithelium. When injury damages this layer faster than it can be replaced, part of it breaks down and an erosion is created.

An important point first: erosive esophagitis is a description of what was seen, not a disease in itself. It tells you how much damage is present, but it does not say what caused it. Several different conditions produce erosions in the esophagus, and they are treated in very different ways. Establishing the cause is the main task that follows this finding, and it is usually the reason biopsies were taken.

Your report may also distinguish between two depths of damage. An erosion is a loss of part of the thickness of the lining. An ulcer is a loss of the full thickness, exposing the tissue beneath. Ulcers indicate deeper injury and are more likely to bleed or to leave scarring as they heal. 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 erosive esophagitis?

Erosive esophagitis is caused by anything that injures the lining of the esophagus faster than it can repair itself. The possible causes differ enough in treatment that identifying the right one matters:

Acid reflux — By far the most common cause. Stomach acid and digestive enzymes flow backward into the esophagus and damage the lining. When reflux is the cause, the condition is also called reflux esophagitis, and the erosions are concentrated in the lower esophagus just above the stomach.
Pill esophagitis — A tablet or capsule lodges against the lining and dissolves there, burning it directly. This typically happens when a pill is swallowed with too little water or just before lying down, and the injury is usually in the middle of the esophagus where it is naturally narrowed. Common culprits include doxycycline and other antibiotics, potassium chloride, iron tablets, nonsteroidal anti-inflammatory drugs, and bisphosphonates for osteoporosis.
Infection — Candida esophagitis, a yeast infection, is the most common and often produces white patches. Herpes esophagitis and cytomegalovirus infection typically cause discrete ulcers. Infections occur most often in people whose immune system is weakened by illness or medication, and sometimes after antibiotic or inhaled steroid use.
Eosinophilic esophagitis — An immune and allergy-driven condition that more often causes rings, furrows, and white specks than frank erosions, but that can produce breaks in the lining, particularly after food becomes stuck.
Caustic injury — After swallowing a corrosive substance such as a strong cleaning product, which causes severe and often extensive damage.
Radiation therapy — Treatment directed at the chest or neck injures the lining during and shortly after the course.
Crohn disease — An uncommon cause, but inflammatory bowel disease can involve the esophagus.

One further reason biopsies are taken from an eroded or ulcerated area deserves mention. A cancer of the esophagus that has broken down at its surface can look much like inflammatory ulceration on endoscopy. Sampling the area is a routine precaution that allows this to be excluded, and in the great majority of cases it is excluded. Ulcers that do not heal after adequate treatment are usually biopsied again for the same reason.

What are the symptoms of erosive esophagitis?

The symptoms of erosive esophagitis come from acid, food, and liquid contacting exposed tissue where the protective lining has been lost. The most characteristic is odynophagia, meaning pain on swallowing, which is more suggestive of erosive damage than heartburn alone. Heartburn, chest discomfort, difficulty swallowing, and a sensation of food sticking are also common.

Symptoms correlate poorly with the amount of damage. Some people with extensive erosions have few complaints, particularly older adults and people with long-standing diabetes, while others with minor damage are very uncomfortable. Vomiting blood, passing black stools, or developing unexplained anemia can indicate bleeding from an erosion or ulcer and warrant prompt assessment, as does progressive difficulty swallowing solid foods or unexplained weight loss.

How is the diagnosis made?

Erosive esophagitis is identified during an upper endoscopy, in which a thin flexible tube with a camera is passed through the mouth to examine the lining of the esophagus directly. This is an endoscopic finding rather than a microscopic one: the endoscopist sees breaks in the lining, which appear as red, raw-looking streaks or patches, sometimes with a white or yellow coating of inflammatory debris. The lining around them may look red and swollen.

Where the erosions are located gives the first clue to the cause. Damage concentrated in the lower esophagus points toward reflux, damage in the middle of the esophagus toward a pill, discrete punched-out ulcers toward a viral infection, and white plaques toward Candida. Erosions along the whole length raise other possibilities.

During the endoscopy, small tissue samples called biopsies are usually taken and sent to a pathologist for examination under a microscope. The purpose of the biopsy is not to confirm that erosions are present, since the endoscopist has already seen them. It is to look for the specific features that point to one cause over another, to check for Barrett esophagus, and to exclude cancer. For this reason, a pathology report will often describe the injury and then say the findings are “consistent with” a particular cause rather than stating it definitively, because the final answer combines the microscope with the endoscopic appearance and your symptoms.

Grading of erosive esophagitis

When erosive esophagitis is caused by reflux, the endoscopist grades how extensive the damage is using the Los Angeles classification. This grade appears on the endoscopy report and guides how long treatment is given:

Grade A — One or more breaks in the lining, each no longer than 5 mm.
Grade B — At least one break longer than 5 mm, but breaks do not run together between the tops of two folds of the lining.
Grade C — Breaks run together between the tops of two or more folds, involving less than three-quarters of the circumference of the esophagus.
Grade D — Breaks involve three-quarters or more of the circumference.

Grades A and B are considered mild and account for the large majority of cases, commonly around 80% or more. Grades C and D are uncommon and indicate more severe disease that needs a longer course of treatment and a repeat endoscopy afterward. Grade B or higher is regarded as conclusive evidence that reflux is the cause; grade A alone is less definitive, because small breaks are occasionally seen in people who do not have reflux disease.

Microscopic findings

When a biopsy taken from an area of erosive esophagitis is examined under the microscope, the pathologist describes both the damage itself and any clues to its cause. Findings that may appear on your report include:

Erosion — Part of the thickness of the squamous lining is missing. The surface is often covered by a layer of inflammatory debris and dead material.
Ulceration — The full thickness of the lining is lost and the underlying lamina propria is exposed. Granulation tissue, the loose repair tissue rich in small new blood vessels that forms at the base of a healing ulcer, is often described.
Inflammatory cells — Immune cells collect at the site of injury. Neutrophils are prominent at the edge of an active erosion or ulcer regardless of the underlying cause, and their presence indicates active damage rather than pointing to any one diagnosis.
Basal cell hyperplasia and elongated papillae — The lining thickens at its base and the projections beneath it extend upward, both signs that the tissue is repairing itself after repeated injury. These are characteristic of reflux.
Spongiosis — Small fluid-filled gaps open between the squamous cells, an early sign of injury.
Reactive and regenerative change — Cells at the edge of an erosion look enlarged and abnormal as they multiply rapidly to close the defect. This can resemble dysplasia, and it is one reason a pathologist may defer judgment on a biopsy taken from actively inflamed tissue and ask for it to be repeated after healing.

Certain additional findings point toward a specific cause:

Fungal organisms — Yeast and branching filaments identified with a special stain indicate Candida esophagitis.
Viral changes — Enlarged cells with characteristic nuclear changes at the edge of an ulcer suggest herpes simplex virus, while similar changes deeper in the tissue suggest cytomegalovirus. Immunohistochemical stains can confirm either.
Foreign material and multinucleated giant cells — Fragments of an undissolved tablet, sometimes surrounded by large immune cells formed in reaction to it, indicate pill esophagitis.
Numerous eosinophils — Fifteen or more per high-power microscope field, particularly if present throughout the length of the esophagus, suggest eosinophilic esophagitis rather than reflux. Smaller numbers are expected in reflux.

What are the possible complications of erosive esophagitis?

Most erosive esophagitis heals completely once the cause is treated. Complications arise mainly when the injury is severe, or when the cause is not identified and the damage continues:

Bleeding — An erosion or ulcer can bleed, sometimes visibly and sometimes slowly enough to cause anemia without any obvious blood loss.
Peptic stricture — Repeated cycles of injury and healing lay down scar tissue that narrows the esophagus, producing progressive difficulty swallowing solid foods. This can usually be treated by stretching the narrowed segment during an endoscopy.
Barrett esophagus — With long-standing reflux, the squamous lining may be replaced by gland-forming cells resembling those of the intestine, a change called intestinal metaplasia. This is Barrett esophagus, which matters because it is the precursor to adenocarcinoma of the esophagus.
Perforation — A rare complication of very deep ulceration, most often after caustic injury.

The cancer risk is worth putting in proportion. Erosive esophagitis does not itself turn into cancer. The risk runs specifically through Barrett esophagus, which develops in only a minority of people with long-standing reflux, and among those who have it, roughly 0.3% per year go on to develop cancer. Most never do.

What happens after this diagnosis?

What follows depends on the cause. Because the erosions themselves heal once the injury stops, treatment is directed at whatever produced them.

When reflux is the cause, a proton pump inhibitor taken once daily before a meal is the mainstay. Mild disease usually heals over about four weeks and more extensive disease over eight, with higher or twice-daily dosing used for grades C and D. Measures discussed alongside medication include weight loss where relevant, stopping smoking, avoiding meals within about three hours of lying down, raising the head of the bed, and reducing alcohol. Many people with severe erosive esophagitis stay on long-term treatment, since it tends to recur when medication is stopped.

When another cause is identified, treatment follows it: antifungal medication for Candida, antiviral medication for herpes or cytomegalovirus, stopping or changing the responsible drug and taking future tablets upright with plenty of water for pill esophagitis, and dietary or anti-inflammatory treatment for eosinophilic esophagitis.

A repeat endoscopy after treatment is generally recommended for Los Angeles grades C and D. This confirms healing, and it allows Barrett esophagus to be assessed properly, since it cannot be reliably identified underneath actively inflamed lining. A repeat examination is also usual when an ulcer was present, to confirm it has closed. Mild erosive esophagitis that responds well to treatment does not normally need a follow-up endoscopy.

Where symptoms persist despite adequate treatment, further testing may be considered, including pH monitoring to measure how much acid actually reaches the esophagus and manometry to assess the muscle function of the esophagus.

Questions to ask your doctor

What caused the erosive esophagitis in my case?
What Los Angeles grade were my erosions, and what does that grade mean?
Were the erosions in the lower esophagus, or elsewhere?
Did my report describe erosions, ulcers, or both?
Did the biopsy show any sign of infection, medication injury, or eosinophilic esophagitis?
Was cancer excluded on the biopsy?
Was there any evidence of Barrett esophagus, and can it be assessed while the lining is inflamed?
Which medication should I take, at what dose, and for how long?
Could any of the medications I already take be contributing, and should any be changed?
Should I have a repeat endoscopy to confirm healing?
Will I need long-term acid-suppressing medication, and what are the risks?
Which lifestyle changes are most likely to help in my case?
What symptoms should prompt me to contact you before my next appointment?