Isolated adrenocorticotropic hormone (ACTH) deficiency.

The case to be reported is that of a 72-year-old woman with isolated adrenocorticotropic hormone (ACTH) deficiency, who complained of anorexia and generalized malaise. The secretions of human growth hormone (HGH), prolactin (PRL), luteinizing hormone (LH), follicle stimulating hormone (FSH), and thyroid stimulating hormone (TSH) were all within normal limit. In spite of the extremely low level of cortisol, the plasma level of ACTH would not rise sufficiently, but a marked response of cortisol to ACTH stimulation was recognized. The postmortem examination revealed a decrease in basophilic or PAS-positive cells of the anterior pituitary gland which also showed a selective loss of ACTH-secreting cells over immunohistochemical study. Electron microscope could easily visualize somatotroph, mammotroph, thyrotroph, FSH- and LH-gonadtroph, but corticotroph was difficult to be discerned. Adrenocortical cells demonstrated atrophy and degeneration, for which the zona fasciculata and zona reticularis were narrowed. The zona glomerulosa was slightly enlarged in width.