These malignant, or cancerous, tumors start in the outer layer of the adrenal gland (the adrenal cortex). Although very rare — only 5 to 10 percent of all adrenal tumors are malignant — they’re often aggressive and can cause many symptoms and discomforts.

Symptoms of these tumors include:

• weight gain
• fluid retention (leading to bloating)
• unusual excess hair growth
• unusual skin changes

If the tumor presses against other organs, it may cause symptoms such as abdominal pain, an unusual feeling of fullness, and unexpected weight loss.