Cushing syndrome in a young woman due to primary pigmented nodular adrenal disease.
OBJECTIVE
To report a case of Cushing syndrome due to apparently sporadic primary pigmented nodular adrenal disease in a young woman.


METHODS
We describe the clinical, biochemical, radiologic, and histologic findings of Cushing syndrome due to the rare condition of primary pigmented nodular adrenal disease.


RESULTS
A 30-year-old woman presented with a 2-year history of worsening itch without rash over her shoulders and arms and weight gain, particularly around the abdomen and face. Careful questioning did not elicit any history of exogenous glucocorticoid use (systemic or topical), including hydrocortisone. On examination, the patient had a slightly rounded and plethoric face, a small buffalo hump, central adiposity, and thin skin with a few small striae on her inner thighs. No features of the Carney complex were observed. Investigations showed hypercortisolism with suppressed corticotropin and normal adrenal imaging despite documentation of enlarged adrenal glands at removal. High-dose dexamethasone administration was followed by a decrease in urinary free cortisol excretion rather than a paradoxical rise as previously reported in primary pigmented nodular adrenal disease. No mutations were detected in the PRKAR1A gene.


CONCLUSIONS
Primary pigmented nodular adrenal disease should be suspected in patients with corticotropin-independent Cushing syndrome who have normal adrenal imaging. The role of genetic testing in apparently sporadic cases is not established, but cumulative experience may be helpful in defining the frequency of PRKAR1A mutations.
Hackman
Kathryn L
KL
Department of Endocrinology and Diabetes, The Alfred, Melbourne, Australia.
Davis
Anna L
AL
Curnow
Paul A
PA
Serpell
Jonathan W
JW
McLean
Catriona A
CA
Topliss
Duncan J
DJ
D000303:Adrenal Cortex Diseases / Q000150:complications* / Q000235:genetics / Q000473:pathology; D000328:Adult; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D003480:Cushing Syndrome / Q000188:drug therapy / Q000209:etiology* / Q000235:genetics / Q000473:pathology; D054756:Cyclic AMP-Dependent Protein Kinase RIalpha Subunit / Q000235:genetics; D003907:Dexamethasone / Q000627:therapeutic use; D005260:Female; D006801:Humans; D009154:Mutation
D000893:Anti-Inflammatory Agents; D054756:Cyclic AMP-Dependent Protein Kinase RIalpha Subunit; C517834:PRKAR1A protein, human; D003907:Dexamethasone