The adrenal glands are small, triangle-shaped organs situated directly on top of each kidney. They regulate the body’s response to stress, metabolism, and blood pressure by producing hormones like cortisol, aldosterone, and adrenaline. The discovery of an adrenal mass, often called an adrenal incidentaloma, is increasingly common due to the widespread use of advanced imaging technologies. The primary concern is whether the tumor is causing symptoms, such as pain, though this is not the typical presentation.
The Direct Answer: How Adrenal Tumors Cause Pain
Adrenal tumors most often do not cause pain, but when they do, the discomfort is usually related to the physical size of the mass or an acute event within the tumor. This pain is generally felt in the flank, back, or upper abdomen. Pain occurs because the mass is physically expanding into the limited space of the retroperitoneum, pushing against nearby organs, nerves, or the diaphragm.
Pain is typically associated with very large tumors, often exceeding six centimeters in diameter. This mechanical pressure exerted on surrounding structures can produce a persistent, dull ache. A sudden onset of severe pain, however, may indicate an acute event, such as a hemorrhage or infarction (tissue death) within the tumor itself. This internal bleeding or lack of blood flow causes the tumor capsule to rapidly stretch, leading to intense pain that requires immediate medical evaluation. Malignant tumors can also cause pain by invading adjacent tissues or bone.
Silent Tumors and Hormone-Related Symptoms
The majority of adrenal masses discovered incidentally are non-functional, meaning they do not overproduce hormones and remain “silent” unless they grow large enough to cause mechanical pressure. The tumors that do cause symptoms often do so through the systemic effects of excess hormone secretion. These are known as functional tumors, and their symptoms can be widespread and affect multiple bodily systems.
Pheochromocytoma
This functional tumor arises from the adrenal medulla and secretes excessive amounts of adrenaline and noradrenaline. This hormonal overload leads to episodic symptoms often described as “spells,” including sudden, severe headaches, profuse sweating, rapid heartbeats (palpitations), and significant high blood pressure. These episodes can mimic panic attacks and cause a feeling of anxiety or impending doom.
Cushing Syndrome
Cushing syndrome results from the adrenal cortex producing too much cortisol. Symptoms of cortisol excess include distinctive weight gain concentrated around the abdomen, face (“moon face”), and upper back (“buffalo hump”). Other signs are easy bruising, muscle weakness, thin skin, and the development of purple stretch marks.
Primary Aldosteronism (Conn’s Syndrome)
Tumors that overproduce aldosterone cause primary aldosteronism. Aldosterone helps regulate blood pressure and electrolyte balance, and its excess causes resistant high blood pressure. It can also lead to low blood potassium levels (hypokalemia), which may cause muscle cramps, muscle weakness, and excessive thirst or frequent urination.
Identifying and Diagnosing Adrenal Masses
Adrenal masses are most frequently discovered during CT or MRI scans performed for unrelated health complaints. Once detected, the medical evaluation aims to determine two factors: whether the tumor is producing excess hormones and whether it shows characteristics suggestive of malignancy. This assessment is essential because even small, non-cancerous tumors that secrete hormones require treatment.
Initial workup involves biochemical testing using blood and urine samples to check for hormone overproduction. A 24-hour urine collection measures fractionated metanephrines to rule out pheochromocytoma, and a low-dose dexamethasone suppression test screens for cortisol excess. Patients with hypertension and low potassium levels are also tested for aldosterone overproduction using plasma aldosterone concentration and plasma renin activity.
Imaging characteristics provide significant clues about the potential for malignancy, with size being a primary factor. Masses smaller than four centimeters are typically monitored, while those larger than six centimeters have an increased risk of being cancerous, prompting surgical removal. Malignancy risk is further assessed by evaluating the tumor’s density on a non-contrast CT scan; a low density is generally reassuring of a benign mass. Small, non-functional tumors deemed benign are often managed with periodic imaging follow-up to monitor for growth.