Endocrine Abstracts

Acromegaly secondary to a lung carcinoïd is a very rare entity. Secretion of GHRH (Growth hormone releasing hormone) or GHRH like by neuroendocrine tumor induces pituitary hyperplasia and a production of Growth hormone (GH) with or without others anterior pituitary hormones. Total resection of lung tumor induces normalisation of pituitary function as in our observation.

AD, 37 years, male, came to our unit for diabetes mellitus and acromegaly. His chest X ray showed a 7 cm right lung tumor. On hormonal exploration there was a very high GH =92 to 132 ng/ml (N<5), high prolactine (PRL)=120 ng/ml (N<20), elevated ACTH=70 pg/ml (N=0–46)) and cortisol =262 ng/ml (N=50–210) without clinical signs of Cushing’s syndrome. Thyreotrop function was preserved but there was a gonadotrop deficit: testosterone =0,91 ng/ml (N=3–5). On MRI there was a huge pituitary process impading the third ventricle and a destroyed sella turcica.

GHRH and 5 HIA (5 hydroxyindolacetic acid) were not evaluated. Surgical exploration and pathology study showed typical picture of carcinoïd in the right lung. On post operative period there was a dramatic fall of GH (=1,2 ng/ml). PRL, ACTH and cortisol normalized and diabetes mellitus disappeared. Three month after surgery MRI showed a significant reduction of pituitary process with partial empty sella.

Conclusion: In this observation even if evaluation GHRH assay and immunohistochimy of the tumor was not available, clinical, biological and radiological evaluation confirmed that all endocrine abnormalities observed in our patient were due to lung carcinoïd.