Addison's disease

(Thomas Addison, 1793 - 1860, English physician), a rare condition due to chronic destructive disease of the adrenal cortex, and characterized clinically by primary adrenocortical insufficiency. Secondary adrenocortical insufficiency, due to lack of ACTH, does not constitute Addison's disease. Most cases of Addison's disease are idiopathic, and may represent autoimmune destruction of the adrenal cortex. Clearly defined causes of Addison's disease are extremely rare, and include tuberculosis (see tuberculosis adrenal), amyloidosis, bilateral adrenal metastases, bilateral haemorrhage, histoplasmosis, sarcoidosis (see histoplasmosis adrenal and sarcoidosis genitourinary tract and haemochromatosis. Historically, tuberculosis was a frequent cause of Addison's disease, but this is now uncommon.

There are few radiological findings. Plain radiographs may demonstrate adrenal calcification in cases due to tuberculosis, histoplasmosis or old haemorrhage. In idiopathic Addison's disease, the adrenals may be markedly atrophic and difficult to detect on CT or MRI. Occasionally, bilateral enlargement due to granulomatous disease or malignancy may be seen on CT or MRI.

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