RESUMO
To detect familial medullary thyroid carcinoma in a premetastatic stage, we administered tests provocative of calcitonin secretion (infusion of calcium or pentagastrin or both) each year for seven years to members of a pedigree now numbering 107. Since 1970, 21 patients converted from normal to abnormal secretory responses (two separate tests in which calcitonin levels exceeded 0.58 ng per milliliter). Twenty of 21 glands removed showed C-cell hyperplasia, and eight of the 20 also showed foci of carcinoma. As compared to the 12 patients with tumors detected during the first year of screening, all of whom had bilateral carcinoma (seven of 12 with local metastases), later carcinomas were smaller (mean diameter of 0.2 vs. 0.8 cm), were unilateral (in all but two cases) and occurred in younger patients (mean age of 14.9 vs. 36.4 years), and none had detectable metastases.
Assuntos
Calcitonina/metabolismo , Carcinoma/genética , Neoplasias da Glândula Tireoide/genética , Adolescente , Neoplasias das Glândulas Suprarrenais/diagnóstico , Adulto , Idoso , Cálcio , Carcinoma/diagnóstico , Carcinoma/cirurgia , Criança , Reações Falso-Negativas , Humanos , Hiperplasia , Metástase Linfática , Pessoa de Meia-Idade , Metástase Neoplásica , Pentagastrina , Feocromocitoma/diagnóstico , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/diagnóstico , Neoplasias da Glândula Tireoide/cirurgia , TireoidectomiaRESUMO
To determine the mechanism by which calcitonin acutely decreases bone resorption in man, salmon or human calcitonin was administered intravenously to five patients with Paget's disease of bone immediately after an iliac crest bone biopsy. After 30 min an adjacent bone biopsy was taken and both were evaluated by light and electron microscopy. The results indicated that calcitonin both decreases the number of osteoclasts and alters the ultrastructure of these cells. Thes acute effects of calcitonin on osteoclasts confirm findings in other species and provide evidence in man that calcitonin, at least in part, retards bone resorption by inhibiting osteoclastic activity.
Assuntos
Calcitonina/farmacologia , Osteíte Deformante/metabolismo , Osteoclastos/efeitos dos fármacos , Animais , Biópsia , Reabsorção Óssea/efeitos dos fármacos , Humanos , Microscopia Eletrônica , Osteíte Deformante/patologia , Osteoclastos/patologia , Osteoclastos/ultraestrutura , SalmãoRESUMO
1. In the fifth year of followup, 8 of 12 original patients thyroidectomized for MTC, diagnosed solely by abnormal calcitonin values, are disease free by all criteria. Elevated calcitonin levels are the only manifestation of active disease in three patients with presumed metastases. 2. Routine annual screening of susceptible individuals is a practical measure and has in 6 cases detected the premalignant condition of G-cell hyperplasia and in 1 patient a premetastatic state of MTC. It is premature to conclude that yearly screening is sufficient to detect all cases of premetastatic disease and for this reason we are recommending a yearly screen with pentagastrin and calcium tests and the more convenient pentagastrin test at 6 month intervals for those in the high-risk age group between 8 and 18. If screening at such intervals proves to be ineffective in preventing the disease in every case, consideration must be given to prophylactic thyroidectomy although we are not currently recommending this precedure. 3. Pentagastrin injection is often a more effective secretagogue for calcitonin than is calcium infusion, but this is not uniformly true. We therefore recommend use of both tests as the most appropriate screening procedure. 4. Epinephrine is a major secretory product of pheochromocytomas in the J-kindred and sequential E/N ratios may be of use in the early detection of pheochromocytoma in other kindreds. 5. Adrenal medullary hyperplasia has been found in 3 adrenal glands and is probably a preneoplastic condition analogous to C-cell hyperplasia.
