PPNAD, Carney Complex and Other Micronodular Adrenal Hyperplasia

Abstract

The Carney complex (CNC) is an endocrine and nonendocrine multiple neoplasia syndrome caused in the majority of cases by inactivating mutations of the PRKAR1A encoding for the regulatory subunit type I alpha of the protein kinase A (PKA). The primary pigmented nodular adrenal disease (PPNAD), leading to the development of Cushing's syndrome, is the most frequent endocrine manifestations of the CNC. Others manifestations includes cardiac and cutaneous myxomas, lentiginosis, GH-producing pituitary adenomas, Sertoli cell tumors, melanotic schwannoma, thyroid, breast, and bone tumors. The PPNAD can be isolated, that is, without other manifestations of the CNC. Apart from this context, an isolated micronodular adrenocortical disease (iMAD) has been described in few cases related to mutations in the genes encoding for phosphodiesterases PDE11A and PDE8B, and to duplication of the PRKACA gene (catalytic subunit Calpha of PKA). To date, other cases of CNC or iMAD remain unexplained.