Presentations

Abstract

Introduction:

Addison's disease, also known as primary adrenal insufficiency, is a disorder caused by failure of the adrenal cortex, resulting in insufficient production of cortisol and mineralocorticoid hormones by the adrenal glands. In this case series, we describe three patients with Addison's disease to highlight the common imaging findings seen in this disease that may be used to help assess the adrenal glands and diagnose adrenal insufficiency.

Case Information:

Case 1: A 61-year-old female who was diagnosed with primary adrenal insufficiency due to bilateral adrenal hemorrhage. During her initial presentation, computed tomography (CT) of the abdomen revealed enlarged and edematous adrenal glands that were concerning for bilateral adrenal hemorrhage. Subsequent cosyntropin stimulation test was positive for primary adrenal insufficiency, and the patient was started on corticosteroid replacement. Repeat CT scan performed a year after her initial presentation demonstrated adrenal glands that remained large. Abdominal CT performed three years after initial presentation revealed atrophic and stable adrenal glands, consistent with her diagnosis of Addison's disease.

Case 2: A 55-year-old male with a history of Addison's disease for more than twenty years who was diagnosed with Polyglandular Autoimmune Syndrome Type II. His head CT showed chronic calcification of bilateral auricular cartilages, and severely atrophic glands were seen on abdominal CT. These findings are compatible with his history of Addison's disease.

Case 3: A 78-year-old male with long-standing history of Addison's disease. Skeletal survey showed calcified pinna on x-ray of the skull, and head CT also demonstrated calcified auricular cartilages bilaterally. Abdominal CT showed atrophic adrenal glands. The patient's imaging findings were consistent with his history of Addison's disease.

Discussion:

Addison's disease is a chronic condition and has many causes, including autoimmune adrenalitis, infection, malignant tumor, hemorrhage, and iatrogenic conditions. Patients with adrenal insufficiency may experience adrenal crisis, an acute life-threatening condition due to insufficient cortisol, so it is important to diagnose and treat this disease. Addison's disease cannot be diagnosed by imaging alone, but abdominal CT is the imaging modality of choice for adrenal assessment. The causes of Addison's disease have different CT findings, and imaging features of the adrenal glands also vary depending on acute, subacute, or chronic primary adrenal insufficiency.

Acute primary adrenal insufficiency may result from bilateral adrenal hemorrhage, which appear as adrenal enlargement on CT scan that may be asymmetrical. Adrenal hemorrhage may progress to adrenal hematomas that appear round or oval on CT. Subacute is defined as less than two years of disease, with CT typically showing enlargement of both adrenal glands with necrotic centers and a rim of contrast enhancement. In chronic primary adrenal insufficiency, CT scan demonstrates small, atrophic remnants of the adrenal glands, as seen in these patient cases.

Calcification of the auricle is an uncommon finding that usually results from ectopic calcification of the auricular cartilages and can manifest as rigid ear. The exact underlying pathogenesis is unclear, but it may be caused by trauma, frostbite, inflammation, or endocrinologic disorders. Adrenal insufficiency is the most common endocrine disorder to be associated with this condition. Calcified pinna can be confirmed on imaging and is seen as dense opacities within the cartilage on skull x-ray and CT. Auricular calcification can precede the development of endocrinopathies by many years and may be the only marker of underlying disease. Therefore, undiagnosed endocrinopathies, especially adrenal insufficiency, should be considered in patients found to have auricular calcification without a known cause.

Conclusion:

In patients with Addison's disease, CT can help evaluate the adrenal glands to determine the etiology and guide management. There should be suspicion of possible underlying adrenal insufficiency in patients with auricular calcification on imaging and no known cause. It is important for clinicians to recognize imaging findings of Addison's disease for early detection and management to prevent life-threatening adrenal crisis.