In general, clinical manifestations of adrenocortical insufficiency do not appear until at least 90% of the adrenal cortex has been compromised. The initial manifestations often include progressive weakness and easy fatigability, which may be dismissed as nonspecific complaints. Gastrointestinal disturbances are common and include anorexia, nausea, vomiting, weight loss, and diarrhea. In patients with primary adrenal disease, increased levels of ACTH precursor hormone stimulate melanocytes, with resultant hyperpigmentation of the skin and mucosal surfaces. The face, axillae, nipples, areolae, and perineum are particularly common sites of hyperpigmentation. By contrast, hyperpigmentation is not seen in patients with secondary adrenocortical insufficiency because melanotropic hormone levels are not increased. Decreased mineralocorticoid (aldosterone) activity in patients with primary adrenal insufficiency results in potassium retention and sodium loss, with consequent hyperkalemia, hyponatremia, volume depletion, and hypotension, whereas secondary hypoadrenalism is characterized by deficient cortisol and androgen output but normal or near-normal aldosterone synthesis. Hypoglycemia occasionally may occur as a result of glucocorticoid deficiency and impaired gluconeogenesis. It is more common in infants and children than adults. Stresses such as infections, trauma, or surgical procedures in affected patients may precipitate an acute adrenal crisis, manifested by intractable vomiting, abdominal pain, hypotension, coma, and vascular collapse. Death follows rapidly unless corticosteroids are replaced immediately.
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Fig.20.41Autoimmuneadrenalitis.Inadditiontolossofallbutasubcapsularrimofcorticalcells,thereisanextensivemononuclearcellinfiltrate.
Primaryadrenocorticalinsufficiencycanbeacute(Waterhouse-Friderichsensyndrome)orchronic(Addisondisease).
ChronicadrenalinsufficiencyintheWesternworldmostoftenissecondarytoautoimmuneadrenalitis,whichoccursinthecontextofautoimmunepolyendocrinesyndromes.
Tuberculosisandinfectionsduetoopportunisticpathogensassociatedwiththehumanimmunodeficiencyvirusandtumorsmetastatictotheadrenalsaretheotherimportantcausesofchronichypoadrenalism.
Patientstypicallypresentwithfatigue,weakness,andgastrointestinaldisturbances.PrimaryadrenocorticalinsufficiencyalsoischaracterizedbyhighACTHlevelswithassociatedskinpigmentation.
It should be evident from the discussion of adrenocortical hyperfunction that functional adrenal neoplasms may be responsible for any of the various forms of hyperadrenalism. While functional adenomas are most commonly associated with hyperaldosteronism and with Cushing syndrome, a virilizing neoplasm is more likely to be a carcinoma. Not all adrenocortical neoplasms, however, elaborate steroid hormones. Determination of whether a cortical neoplasm is functional or not is based on clinical evaluation and measurement of the hormone or its metabolites in the laboratory.
MORPHOLOGYAdrenocorticaladenomasweredescribedearlierinthediscussionsofCushingsyndromeandhyperaldosteronism.Mostcorticaladenomasdonotcausehyperfunctionandusuallyareencounteredasincidentalfindingsatthetimeofautopsyorduringabdominalimagingforanunrelatedcause.Infact,thehalf-facetiousappellationof“adrenalincidentaloma”hascreptintothemedicallexicontodescribetheseincidentallydiscoveredtumors.Oncutsurface,adenomasusuallyareyellowtoyellow-brown,owingtothepresenceoflipidwithintheneoplasticcells(see