pituitrin and Apudoma

A variety of cells found in the pituitary and pineal glands, sympathetic nervous system and adrenal glands, the gut, pancreas, thyroid (C-cells), chemoreceptors (type I-Cells), lungs (P-cells), skin (melanocytes) and the urogenital tract have a common origin from the neural crest. These cells are programmed for neuro-endocrine function and, as a group, can be regarded as one of the physiological control systems. They secrete a variety of amine and peptide hormones and have common cytochemical characteristics from which the term APUD cell is derived. Tumours of these cells are referred to as 'apudomas' and may synthesise not only their own hormones but also those which are normally produced by other APUD cells. The relevant physiological properties of some of the peptides which have been described relatively recently are discussed and the principal clinical syndromes produced by the APUDomas are described.

Topics: Adenoma, Islet Cell; APUD Cells; Apudoma; Cushing Syndrome; Endocrine System Diseases; Gastrointestinal Neoplasms; Hormones; Humans; Malignant Carcinoid Syndrome; Neoplasms, Nerve Tissue; Pancreatic Neoplasms; Paraneoplastic Endocrine Syndromes; Pheochromocytoma; Pituitary Neoplasms; Thyroid Neoplasms; Vasopressins; Zollinger-Ellison Syndrome

Two cases of Schwartz-Bartter syndrome are reported. Both were due to malignant anaplasic tumours of the APUD type with multiple abnormal endocrine secretion, and both were accompanied with hypouricaemia of uncertain significance. The authors believe that the association of hypernatraemia with hypouricaemia should alert clinicians to the possibility of a syndrome of inappropriate antidiuretic hormone secretion (SIADH) of malignant origin.

Topics: Apudoma; Carcinoma, Small Cell; Female; Humans; Hyponatremia; Inappropriate ADH Syndrome; Male; Middle Aged; Uric Acid; Vasopressins

Medullary thyroid carcinoma (MTC) is a known apudoma producing calcitonin, prostaglandins and serotonin. It can present itself as a familial or sporadic form or as part of a multiple endocrine adenomatosis. We present here the case of a patient admitted with a four-year history of diarrhea, enlargement of the thyroid and palpable lymph nodes in the right side of the neck. There was no uptake of 131I in the right lobe of the thyroid and the serum calcitonin levels were very high. With the diagnosis of MTC a total thyroidectomy mas performed developping within hours of the surgical procedure a picture of diabetes insipidus with 31 liters of urine output in the first 48 hours. It responded to vasopressin and disappeared spontaneously in two weeks. We have considered the different mechanisms that could explain the development of diabetes insipidus, and after failing to find one, we especulate at prostaglandins could play an important role in the synthesis and/or release of ADH. The sudden depletion of prostaglandins after removal of the neoplasm that produced them could account for the diabetes insipidus in our patient. We have not found any similar case described in the literature. We call attention to the need for a close postoperative observation of patients operated for MTC for the possible onset of diabetes insipidus.

Topics: Adult; Apudoma; Diabetes Insipidus; Humans; Male; Postoperative Complications; Thyroid Neoplasms; Thyroidectomy; Vasopressins

The capacity which the cells of some tumors have of synthesizing, storing, and releasing hormonal polypetides constitutes the basic characteristic of the neoplasms of the APUD system. On many occasions these polypeptides are released as hormonal precursors of high molecular weight, with a minimal biological action in comparison with the real hormone (big ACTH, big gastrin, etc.), and they have no clinical expressivity. On other occasions they reproduce, however, the clinical syndrome of the hormone released in excess. The production of multiple hormones by a single tumor is not a common event. Here we present the case of a patient with an oat-cell carcinoma of the lung and a carcinoma of the pancreas, both histopathologically primitive. In this patient a syndrome of inadequate secretion of antidiuretic hormone was detected. By means of radioimmunoassay techniques, the existence of antidiuretic hormone, ACTH with a predominance of the components of high molecular weight (big ACTH and beta-LPH) and MSH was demonstrated in the tumoral extracts from the lung, pancreas, and from a mediastinal metastatic lymph node. While the concentrations of ACTH were much greater in the lung than in the pancreas, the opposite occurred for the antidiuretic hormone. The synthesis of MSH by the hypophyseal gland or by tumors is not at present recognized, but rather is considered as a degradation product during the process of extraction. The APUD system makes up the morphologic substrate of the syndromes of familiar multiple endocrine adenomatosis. The present case could represent a variant of sporadic multiple endocrine neoplasms which would have the same anatomical basis.

Topics: Adrenocorticotropic Hormone; Apudoma; Diagnosis, Differential; Hormones, Ectopic; Humans; Lung Neoplasms; Lymphatic Metastasis; Male; Melanocyte-Stimulating Hormones; Middle Aged; Pancreatic Neoplasms; Paraneoplastic Endocrine Syndromes; Peptides; Radioimmunoassay; Vasopressins