gastrins and Thymus-Neoplasms

In a substantial proportion of cases with endocrine malignant disease the primary lesion cannot be localised and the pathologist hesitates upon the origin of the tumour. Well differentiated neuroendocrine carcinomas of the small bowel can usually be identified by the strong serotonin immunoreactivity, but foregut carcinoids may also stain positive for serotonin and the differential diagnosis between the various foregut tumours may be difficult. We examined if immunostaining for gastrin-releasing-peptide (GRP) may aid in establishing the origin of an unknown neuroendocrine tumour. Tumour tissue from 79 patients (27 lung carcinoids, 4 thymic carcinoids, 4 gastric neuroendocrine tumours, 17 pancreatic well differentiated neuroendocrine carcinomas, 1 duodenal well differentiated neuroendocrine tumour and 26 well differentiated neuroendocrine carcinomas of the small bowel) were immunostained with antibodies against GRP and serotonin. Positive staining for GRP was found in 12/27 lung carcinoids. All other tumour types were consistently GRP-negative (p?

Topics: Diagnosis, Differential; Female; Gastrins; Gastrointestinal Neoplasms; Humans; Immunohistochemistry; In Vitro Techniques; Lung Neoplasms; Middle Aged; Neoplasms, Unknown Primary; Neuroendocrine Tumors; Peptides; Prospective Studies; Thymus Neoplasms

A series of 25 apudomas of the gastrointestinal tract (22 cases), bronchus (2 cases), and thymus (1 case) were subjected to staining with silver impregnation (Masson-Fontana and Grimelius) techniques and with the commercial immunoperoxidase kits for the peptide hormones adrenocorticotropin, calcitonin, gastrin, glucagon, growth hormone, human chorionic gonadotropin (hCG), insulin, somatostatin, and vasoactive intestinal peptide. Of the tumors studied, 16 were regarded as malignant, and 5 of the patients showed clinical symptoms due to inappropriate hormone secretion. A total of 16 tumors contained cells positive for 1 or more (6 were multihormonal) of the hormones studied. One bronchial carcinoid stained for hCG, which has not been previously reported. In addition, one of the rectal carcinoids contained somatostatin-positive cells, only once described previously. The thymic tumor proved frankly malignant, most probably identical to the oat-cell carcinoma recently described. The findings also substantiate the recent suggestion that gastrointestinal carcinoids cannot be adequately classified on the basis of silver stains only and strongly advocate the use of the immunoperoxidase kits in routine assessments of all the endocrinologically active tumors, whatever their localization might be.

Topics: Adrenocorticotropic Hormone; Adult; Aged; Apudoma; Bronchial Neoplasms; Calcitonin; Chorionic Gonadotropin; Female; Gastrins; Gastrointestinal Neoplasms; Glucagon; Growth Hormone; Humans; Immunoenzyme Techniques; Male; Middle Aged; Peptides; Somatostatin; Thymus Neoplasms; Vasoactive Intestinal Peptide

Topics: Adult; Carcinoid Tumor; Female; Gastrins; Humans; Male; Middle Aged; Serotonin; Thymus Neoplasms; Zollinger-Ellison Syndrome