Unravelling the mystery in a case of persistent ACTH-independent Cushing's syndrome

We present a rare variety of adrenocorticotrophic hormone (ACTH)-independent Cushing's syndrome known as primary pigmented nodular adrenocortical disease (PPNAD).

The patient initially underwent unilateral adrenalectomy for what was thought to be a left adrenal adenoma.

Partial resolution of symptoms and demonstrable persistent hypercortisolism after surgery prompted further evaluation with findings leading to the diagnosis of Carney complex. A review of the adrenal histology was consistent with PPNAD.

This entity of PPNAD, which has rarely been reported in Asians, forms part of the Carney complex. The diagnosis may not be simple and straightforward, as illustrated in this patient.