vasoactive-intestinal-peptide and Thymus-Neoplasms

The case of a 33-year-old-woman with Multiple Endocrine Neoplasia Type 1 (MEN1) syndrome and acromegaly due to ectopic growth hormone-releasing hormone (GHRH) secretion by a thymic carcinoid tumour is reported. Immunohistochemistry revealed positive immunoreactivity for GHRH, vasoactive intestinal polypeptide, somatostatin and alpha-subunit in the tumour cells. A previously undescribed new germ line mutation of the MEN1 protein gene was revealed.

Topics: Acromegaly; Adult; Antineoplastic Agents; Carcinoid Tumor; Fatal Outcome; Female; Germ-Line Mutation; Growth Hormone-Releasing Hormone; Humans; Immunohistochemistry; Multiple Endocrine Neoplasia Type 1; Neoplasm Proteins; Peptides, Cyclic; Somatostatin; Thymus Neoplasms; Vasoactive Intestinal Peptide

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