Adrenal Calcification: Causes, Diagnosis, and Complications

Adrenal calcification is almost always an incidental finding, spotted on a CT scan ordered for something else entirely. In a study of 540 consecutive patients with calcified adrenal glands, roughly seven out of ten had no identifiable cause, and the vast majority had completely normal adrenal function. That said, the remaining cases do include some serious possibilities, from old infections like tuberculosis to adrenal tumors, so the finding usually triggers at least a basic workup to rule out problems that need attention.

How Common Is It and How Is It Found

Most people with adrenal calcification never know they have it until a radiologist mentions it on a report. In a Chinese surgical series spanning seven years and more than 5,000 patients who underwent adrenal surgery, adrenal calcification turned up in about 1.5% of cases.¹ Among the 540-patient Mayo Clinic series, 87% of calcifications were discovered incidentally on imaging done for unrelated reasons.² The median age at detection was 65, and men were slightly more commonly affected than women. So if you have been told you have a calcified adrenal gland, you are in good company, and the odds strongly favor a benign explanation.

The Most Common Causes

The single largest category is idiopathic, meaning no clear cause can be identified. In the 540-patient study, 72% of adrenal calcifications fell into this bucket.² That does not mean nothing happened. In most of these cases, the calcification likely represents an old hemorrhagic or necrotic event within the gland that healed and left behind calcium deposits, but there is simply no way to trace the original insult decades later.¹

Adrenal tumors accounted for about 21% of cases in that same series. Of the calcified tumors, the overwhelming majority were benign. Adenomas made up about two-thirds of the benign group. The most common malignancy found in a calcified adrenal gland was metastasis from cancer elsewhere in the body, not a primary adrenal cancer.²

Hemorrhage was identified in about 5% of cases, and infiltrative diseases such as infections in roughly 1%.² That 1% figure for infiltrative disease in a modern Western referral center can be misleading, though. In parts of the world where tuberculosis is still common, infection is a major cause of calcified adrenal glands, as covered below.

Tuberculosis and Other Infections

Before autoimmune disease became the leading cause of adrenal insufficiency in wealthy countries, tuberculosis held that title for decades. TB can seed the adrenal glands through the bloodstream, triggering inflammation, tissue death, and eventually calcification as the body walls off the damaged tissue with calcium. In one study of patients with Addison’s disease, adrenal calcification appeared in over half of those whose disease was caused by tuberculosis, while none of the patients with other causes showed calcification.³ This makes calcification a fairly reliable marker for a TB origin when it appears alongside adrenal insufficiency.

The calcification pattern also changes over time. In a study of 42 patients with TB-related Addison’s disease, CT scans revealed calcification in half the cases. Patients with longer disease duration were more likely to show calcification and preserved adrenal contours, while those scanned earlier tended to have enlarged glands with rim enhancement and a mass-like appearance instead.⁴ In practical terms, TB-related adrenal calcification is usually a late finding. Early in the infection, the glands swell; over months to years they shrink and calcify.

Histoplasmosis, a fungal infection common in certain river valleys, can produce similar changes. In a small series of seven patients with confirmed disseminated histoplasmosis, every single one showed adrenal abnormalities on CT, ranging from faint calcium flecks in mildly enlarged glands to dense calcification in severely affected ones.⁵ If you live in or have traveled through regions where histoplasmosis is endemic, this is worth mentioning to your doctor when adrenal calcification shows up on a scan.

Adrenal Hemorrhage as a Precursor

The adrenal glands have a rich blood supply relative to their size, which makes them vulnerable to hemorrhage under certain conditions. Newborns are particularly susceptible during traumatic delivery, and adults can experience adrenal bleeding from blood-thinning medications, severe sepsis, major surgery, or physical trauma. When the blood clot inside the gland organizes and heals, calcium deposits often accumulate in its wake.

Neonatal adrenal hemorrhage is one of the better-understood routes to calcification later in life. In some adults with idiopathic adrenal calcification, the pattern is consistent with an old hemorrhage that occurred during or shortly after birth.⁶ The bleeding resolves on its own, the gland scars, and calcium is deposited. Decades later, a CT scan picks it up. In the neonatal setting, follow-up imaging often reveals triangular calcifications in the adrenal bed that are considered a hallmark of prior hemorrhage.⁷

Waterhouse-Friderichsen syndrome, a devastating complication of severe bacterial sepsis, represents the extreme end of adrenal hemorrhage. In this condition, both adrenal glands undergo massive bleeding and necrosis. Survivors, though rare, can develop bilateral adrenal calcification and may need lifelong hormone replacement.

What the Calcification Looks Like on a Scan

Radiologists classify adrenal calcifications by their shape and distribution, and those patterns can offer clues about the underlying cause. On CT, calcifications appear as bright white spots, typically with a density of 100 Hounsfield units or more.¹ The 540-patient series broke down the morphology into four main types:

Punctate: small, scattered flecks of calcium, the most common pattern at 58%.
Coarse: larger, chunkier deposits, seen in about 30%.
Linear or curvilinear: thin lines of calcium tracing the gland’s outline, about 9%.
Rim-like: a shell of calcium around a central structure, seen in only 3%.

These percentages come from the same Mayo Clinic cohort.² Almost all calcifications were on one side only, with bilateral involvement in just 6% of patients. Bilateral calcification tends to raise more concern because it can point to systemic causes like infection or a genetic storage disorder.

Rim-like calcification in the adrenal area sometimes turns up in rare parasitic infections. A hydatid cyst caused by the parasite Echinococcus granulosus can settle in the adrenal gland, and in its final, inactive stage the cyst wall calcifies into a visible shell.⁸ This is extremely rare even in regions where hydatid disease is common, but the calcified-wall appearance on CT can be distinctive enough to suggest the diagnosis.

Tumors and Calcification

Finding calcium in an adrenal mass is not automatically alarming. In the large Mayo Clinic series, roughly four out of five calcified adrenal tumors were benign.² Adenomas were the most frequent type, and these are the same benign nodules commonly found as adrenal incidentalomas in the general population. When an adenoma contains calcium, it can sometimes make the imaging assessment more complicated because the high density of calcium throws off the standard density measurements radiologists rely on to tell benign from malignant masses.

That said, malignancies can calcify too. The most common malignant calcified adrenal lesion was metastatic disease, often from lung, breast, or kidney cancers that spread to the adrenal gland. Among the less common primary adrenal malignancies, pheochromocytomas occasionally show calcification. One case report described a pheochromocytoma with ring-like calcification on CT and an extremely high calcium density above 500 Hounsfield units.⁹ Myelolipomas, which are benign tumors containing fat and bone-marrow-like tissue, can also contain scattered calcium, though the fat component usually makes them easy to identify on imaging.

Interpretive errors can occur when radiologists evaluate adrenal masses using standard washout analysis on CT without accounting for the presence of calcification, fat, or unusually high or low density within the nodule.¹⁰ If you are told you have a calcified adrenal mass, the workup may involve additional imaging steps beyond the standard protocol to properly characterize it.

Does Adrenal Calcification Affect Hormone Production

This is often the first question patients ask, and the reassuring answer is that in the vast majority of cases, it does not. Two young adults with extensive idiopathic adrenal calcification were tested with a range of hormone stimulation tests, and both had completely normal cortisol responses. One also showed a normal adrenaline response to induced low blood sugar, indicating that even the adrenal medulla was unaffected.⁶ The authors concluded that even extensive calcification can coexist with fully functional adrenal glands.

In a separate clinical series of 75 patients with calcified adrenal lesions, endocrine testing showed that about 95% had no hormonal abnormality at all. The remaining 5% split between primary aldosteronism (excess aldosterone) and Cushing syndrome (excess cortisol).¹¹ So while hormonal overproduction is possible, it is the exception. Adrenal insufficiency from calcification alone is also uncommon; when it does occur, it is usually tied to a systemic cause like tuberculosis that has destroyed most of the glandular tissue on both sides.

That said, researchers have recommended lifelong follow-up for people with idiopathic adrenal calcification, because we still know relatively little about whether the calcification can progress and gradually impair gland function over many years.⁶ A periodic check of cortisol levels is low-cost and noninvasive, and it provides peace of mind.

When Surgery Enters the Conversation

Most calcified adrenal lesions do not need to be removed. The general approach is watchful waiting for lesions smaller than about 3 centimeters that do not enhance with contrast dye and show no hormonal activity. The threshold for recommending surgery has shifted over time. Some guidelines have suggested that any adrenal mass between 4 and 6 centimeters can be safely monitored, while masses 6 centimeters and above warrant removal because the risk of malignancy rises with size.⁹

In the 75-patient surgical series, only about 29% of patients who underwent surgery were judged to have benefited from it. The median lesion size in the group that benefited was 5.5 centimeters, compared to 3.7 centimeters in the group that did not benefit. Analysis suggested that a diameter of roughly 4.5 centimeters offered the best balance between catching meaningful pathology and avoiding unnecessary operations, though the authors stressed that size alone is not enough and that symptoms like uncontrolled high blood pressure and any suspicion of malignancy should factor into the decision.⁹

For most people with a small, incidental, non-functioning calcified adrenal lesion, the practical recommendation boils down to periodic imaging follow-up and a baseline hormone check. Surgery comes into play when the mass is large, growing, hormonally active, or has features on imaging that raise concern for malignancy.

Wolman Disease and Other Genetic Causes

Bilateral adrenal calcification in an infant is a very different clinical scenario from the incidental unilateral finding in a 65-year-old. One of the most striking genetic causes is Wolman disease, a rare autosomal recessive condition in which the body lacks the enzyme needed to break down certain fats. Lipids accumulate in the adrenal glands, liver, spleen, and other organs. On CT, the hallmark is stippled calcification of both enlarged adrenal glands without distortion of the normal gland shape, accompanied by a fatty liver and an enlarged spleen.¹² The disease typically presents in the first months of life with severe malabsorption and failure to thrive.¹³

Wolman disease is rare and severe enough that bilateral adrenal calcification in a sick infant essentially narrows the diagnosis to a short list. However, a milder form of the same enzyme deficiency, called cholesteryl ester storage disease, can present later in childhood or adulthood with subtler symptoms. While it does not typically produce the dramatic adrenal calcification seen in Wolman disease, it represents a spectrum of the same underlying metabolic problem and may occasionally contribute to adrenal changes.

Practical Takeaways for Patients

If a CT report mentions adrenal calcification, the standard next steps are usually straightforward. Your doctor will likely order a basic set of blood and urine tests to check cortisol levels and screen for excess hormones like aldosterone and catecholamines. If the calcification sits within a mass, its size and imaging characteristics determine whether additional scans, a biopsy, or surgical consultation are warranted. For lesions under 3 to 4 centimeters with no hormonal activity and no worrisome imaging features, follow-up imaging at intervals of 6 to 12 months for a period of time is the typical approach.

One thing worth knowing is that the presence of calcium in an adrenal mass does not reliably distinguish benign from malignant. Less than one in five calcified adrenal lesions is associated with malignancy including pheochromocytoma, and even among those, metastatic disease from another primary cancer is more common than a cancer originating in the adrenal gland itself.¹ So calcification is neither a green light nor a red flag on its own. Context matters: your age, medical history, symptoms, whether the finding is on one side or both, and what the rest of the gland looks like on imaging all feed into the interpretation.

For people with a history of tuberculosis, travel to endemic areas for fungal infections, or a family history of rare metabolic diseases, mentioning those details to your doctor can shift the workup significantly. A calcified adrenal gland in someone who had TB twenty years ago tells a very different story than the same finding in someone with a known lung cancer. The calcification itself is just the footprint. The clinical detective work lies in figuring out what left it behind.

1
Oxford Academic. Rare benign adrenal lesions
2
PubMed Central. Etiology, morphology, and outcomes of adrenal calcifications in 540 adult patients—a retrospective single-center study
3
PubMed. Clinical clues to the cause of Addison’s disease
4
PubMed. Addison’s disease due to adrenal tuberculosis: contrast-enhanced CT features and clinical duration correlation
5
PubMed. Histoplasmosis of the adrenal glands studied by CT
6
PubMed. Functional significance of idiopathic adrenal calcification in the adult
7
Europe PMC / Wiley (Clinical Case Reports). Neonatal adrenal findings: significance and diagnostic approach. Description of two cases.
8
PubMed Central. Primary hydatid cyst of adrenal gland: Case report
9
Scientific Reports. An 8-year clinical experience with diagnosis and treatment of adrenal lesions with calcification – Section: Discussion
10
Radiographics. Technical and Interpretive Pitfalls in Adrenal Imaging
11
Scientific Reports. An 8-year clinical experience with diagnosis and treatment of adrenal lesions with calcification
12
Radiology Case Reports. CT features of Wolman disease (lysosomal acid lipase enzyme deficiency) – A case report
13
PubMed Central. Targeting Wolman Disease and Cholesteryl Ester Storage Disease: Disease Pathogenesis and Therapeutic Development