Primary pigmented nodular adrenocortical disease (PPNAD): single centre experience

Background: Primary pigmented nodular adrenocortical disease (PPNAD) is a rare cause of Cushing's syndrome (CS) in childhood. We describe a case series of patients presenting at our centre along with a review of the literature. Methods: A retrospective analysis of six index cases and one family were done for demographic features, hormonal profile, imaging findings, genetic mutation status, histopathologic findings and follow-up details. Diagnosis was based on biochemistry and confirmed with histopathology and or genetic mutation. All patients had suppressed 8 am adrenocorticotropic hormone (ACTH) (<10 pg/mL) despite evidence of hypercortisolism. Results: The mean age in our cohort was 8.2 years (range 15 months to 20 years). All patients presented with overt CS, including one patient with cyclic Cushing's. Three patients had additional features of Carney complex (CNC). Imaging did not reveal any obvious mass lesions on computed tomography (CT), the classical beaded appearance was present in only two of the patients. Mutation analysis was positive in three patients. Five patients underwent bilateral adrenalectomy and had features of PPNAD on histopathology. Conclusions: PPNAD is a rare cause of ACTH-independent CS in childhood and may signal underlying CNC. Patients with younger age of onset with overt CS may still have a mutation in the PRKAR1A gene and warrant genetic testing.