Neurocristopathy, neuroendocrine pathology and the APUD concept.

The neurosecretory cells of the hypothalamus, and the cells of the pituitary gland and the pineal, are here grouped together as a central neuroendocrine division of the APUD series. The larger, peripheral division comprises the remainder of the original series. All the cells are proven or presumptive derivatives of neuroectoderm so that, with the present exception of the parathyroid gland and its products, peptide hormone endocrinology becomes neuroendocrinology. It follows that the pathology of the APUD cell series must be regarded as neuroendocrine and it is suggested that it can best be expressed by the term neurocristopathy (Bolande, 1974). Tumours of the series, properly neurocristomas, are preferably called apudomas because their common cytochemical (APUD) and ultrastructural characteristics provide the pathologist with a ready means of diagnosis.