An oncocytoma is a benign tumor made up of oncocytes (unusually large cells that tend to form into tumors).

Oncocytomas can occur in any organ, but they are particularly common in the kidneys and salivary glands. Although seldom cancerous, the tumors can grow quite large and affect the function of surrounding glands.

Risk Factors

There are no known risk factors that contribute to oncoctyomas, although doctors suspect it is a genetic mutation. The disease is most common in women aged 70 to 80, so gender and age may also play a role.

Signs and Symptoms

Like most tumors, oncocytomas are generally asymptomatic, which means that they do not produce any symptoms until the tumor is advanced in size. Most cases are discovered by chance when the patient undergoes tests for an unrelated condition.

In salivary gland oncocytoma, the first symptom is usually a firm, painless mass in the cheek or jaw area. The condition can be bilateral, or present on both sides of the face. Renal oncocytomas usually produce hematuria (blood in the urine), flank pain, and in more advanced cases, a noticeable mass in one or both kidneys.

Diagnosis and Staging

Diagnostic procedures depend on where the oncocytoma is present. Often, the tumor is found incidentally when the patient is tested for a different condition. Salivary gland tumors are usually confirmed through a biopsy, wherein a tissue sample is extracted from the bump for examination. This will also determine whether or not the tumor is malignant.

For renal oncocytoma, the first diagnostic test is usually a computerized tomography (CT) scan of the abdomen, which will show the location and size of the bump. This is often accompanied by an intravenous contrast medium, which coats the organs in a high-contrast solution to show the exact location of the bump. A biopsy will then be performed to determine the nature of the tumor (i.e., whether it is benign or malignant)

Staging is performed only when the tumor is found to be cancerous. Doctors usually perform a regional lymphadenopathy, or testing of the surrounding organs, to see if the tumor has metastasized.

Outlook (Prognosis)

Since most oncocytomas are benign, the prognosis is usually excellent as long as the tumor has not caused any serious complications. There are very few cases of recurring tumors and local invasion, and most of them are believed to be a genetic condition rather than oncocytoma.

Treatment

Oncocytomas are usually cured by partially or completely removing the affected organs. Since the tumor rarely spreads, this often cures the conditions completely with little to no chance of recurrence. If a kidney is removed, the patient may have to undergo hemodialysis to replace kidney function while they recuperate.

Prevention

Doctors aren’t sure what causes oncocytomas, so there are no clear steps that can help lower oneís risk. The best form of prevention is regular screening of the parotid and abdominal areas, especially when other family members have been affected.