ECE2014 Poster Presentations Clinical case reports Thyroid/Others (72 abstracts)
1Clinic for Endocrinology, Diabetes and Metabolic Diseases, Clinical Centre of Serbia, Belgrade, Serbia; 2Institute for Medical Research, Belgrade, Serbia; 3Institute of Pathology, School of Medicine, University of Belgrade, Belgrade, Serbia.
The co-secretion of GHRH and GH has been described previously in a patient with GHRH producing pituitary somatotroph adenoma. Here we present a patient with MEN1 and ectopic secretion of both GHRH and GH from a neuroendocrine lung tumor.
A 52-year-old woman was diagnosed in 2009 with two lung tumors, 4 cm right upper lobe tumor, and 2 cm left lower lobe tumor. Owing to a mild coarsening of facial features, acromegaly was suspected. Endocrine studies showed lack of GH suppression during oGTT, increased serum levels of IGF1, GHRH, and Chromogranin A, suggesting ectopic acromegaly. Pituitary MRI showed hyperplasic pituitary. Octreoscan revealed avid take-up of tracer in the right lung tumor only. The patient underwent two consecutive thoracic surgical procedures. Both tumors were characterized as well-differentiated neuroendocrine carcinomas of primary pulmonary origin. The left sided tumor showed no GHRH, GH, or ghrelin immunoexpression. The right sided tumor stained positive for both GHRH and GH. All GH positive cells were positive for GHRH receptor as well. Postoperative Octreoscan was negative, neuroendocrine tumors normalized. Normal IGF-1, GH suppression during OGTT, immeasurable GHRH, and pituitary shrinkage, confirmed ectopic acromegaly. The patient was later diagnosed with nonfunctioning hyperplasia of the left adrenal gland, and primary hyperparathyroidism. Analysis of MEN1 gene revealed Arg355Trp mutation in exon 8 of the MEN1 gene.
To our knowledge, this is the first case describing ectopic secretion of both GHRH and GH from an extracranial tumor. The presence of GHRH receptor on GH positive cells may suggests possible autocrine/paracrine effect of GHRH on GH synthesis and/or secretion in neuroendocrine tumor cells.