Endocrine pathological analysis of primary pigmented nodular adrenocortical disease

We have studied eleven cases of the adrenal with primary pigmented nodular adrenocortical disease (PPNAD) by immunohistochemistry of all steroidogenic enzymes involved in cortisol biosynthesis, by in situ hybridization of P450C17 in seven cases in order to localize the sites of steroidogenesis and by chromosome suppression in situ hybridization of genomic DNA in five cases in order to determine possible genetic abnormalities of the disorder. Immunoreactivity of all the enzymes examined was intense in almost all the cells in adrenocortical nodules while internodular adrenal cortex, including the cases without cortical atrophy, was negative for the enzymes with the exception of 3 beta HSD. In situ hybridization studies of P450C17 yielded results consistent with those of immunohistochemistry. These results may be consistent with autonomous cortisol production by the nodular cells and indicate that almost all of the cells in the cortical nodules produce cortisol, which can explain the presence of hypercortisolism despite small sizes of adrenals in PPNAD. Chromosome suppression in situ hybridization analysis demonstrated possible genetic defects in chromosome 16 in this disorder.