Endocrine Abstracts

Introduction: Carneys complex is an uncommon cause of ACTH independent cushings syndrome which occurs as a combination of myxomas, spotty pigmentation and endocrine overactivity. Primary pigmented nodular adrenocortical disease (PPNAD) is seen in 25–45% of patients with Carneys complex.

Methods: Three patients who were suspected with carneys complex were studied to look if their biochemical radiological and clinical characters could predict postoperative diagnosis of carneys complex.

Clinical presentation: Mean age of onset of symptoms was 17 years. All the patients had diabetes hypertension, cushingoid features and spotty pigmentation of the face.

Investigations: Elevated blood sugars, normal serum electrolytes, Baseline cortisol (mean 17.3 μg/dl) Dexamethasone suppressed cortisol was significantly higher (mean 19.9 μg/dl) than baseline cortisol, supressed serum ACTH, CT abdomen showed unilateral nodular lesion in two cases with other adrenal normal sized with nodular borders and one case showed bilateral normal sized adrenals with nodular borders. Gross and HPE was suggestive of bilateral PPNAD. To confirm PPNAD, sequence analysis and deletion testing of PRKAR1A gene was done. Mutation was found in 2 out of 3 patients. A new variant in PRKAR1A gene was identified in one patient (C769G>A; E 257K). Genetic testing is negative in one patient.

Conclusion: Multiple lentiginosis, a higher dexamethasone suppressed cortisol compared to basal cortisol suppressed ACTH and radiological evidence of nodular adrenals can predict carneys complex in a patient with cushings syndrome. Genetic testing could be negative, which is not unusual as positive genetic testing is found only in 60–70% of patients.