Acromegaly is caused by a primary growth hormonesecreting pituitary adenoma in more than 95% of the cases. In a small number of patients, it is the result of hypersecretion of growth hormone-releasing hormone (GHRH). Clinical and laboratory findings are similar in both conditions, and the diagnosis of a GHRHsecreting tumor is possible only by identification of GHRH in the tumor or circulation. We report the case of a 61-year-old woman referred to the Hospital Naval Marcílio Dias to investigate a pulmonary mass. The mass was large and calcified, suggesting a hamartoma. The patient also had acromegalic features, elevated serum insulin-like growth factor-1 (IGF-1) levels, and no GH suppression after an oral glucose tolerance test. Magnetic resonance imaging (MRI) showed a diffusely enlarged pituitary gland, suggestive of hyperplasia. The hypothesis of acromegaly secondary to ectopic GHRH secretion by the pulmonary mass was made. A left pneumectomy was performed and histopathologic analysis revealed a carcinoid tumor. A fragment of the tumor was sent for special stains and GHRH was identified by immunohistochemistry. The clinical and biochemical aspects of acromegaly improved 2 weeks after surgery. One year later, serum GH and IGF-1 levels were normal and MRI revealed a partial empty sella. The differential diagnosis of somatotroph adenoma and ectopic GHRH hypersecretion is difficult but is essential to appropriate therapy.A cromegaly is a rare disease caused by a primary growth hormone-secreting pituitary adenoma (classic acromegaly) in the large majority of the cases. 1 Less than 5% of cases are caused by eutopic tumors (hypothalamic gangliocytomas, hamartomas, and gliomas) or ectopic tumors (carcinoid tumors, pancreatic endocrine tumors, adrenal adenoma, smallcell lung cancer, and pheochromocytoma) secreting growth hormone-releasing hormone (GHRH). This condition is termed ectopic acromegaly. 2 In addition, acromegaly caused by ectopic 6H hypersecretion is extremely rare. 3 We report a patient with acromegaly resulting from ectopic GHRH secretion by a pulmonary carcinoid tumor.
CASE REPORTA 61-year-old white woman was referred to the Hospital Naval Marcílio Dias for evaluation of a pulmonary mass in April 2000. The mass was extensively studied by bronchofibroscopy, helicoidal tomography, and magnetic resonance imaging (MRI). The mass was approximately 8 cm in diameter, calcified, and in close contact with mediastinal vessels, suggesting a hamartoma. No metastatic lesions were found. The patient exhibited clinical signs of acromegaly with typical facial features and acral changes. She reported progressive increase in hand and foot size. Hypertension had been present for 10 years. She reported arthralgia, hoarseness, and hyperhidrosis. Physical examination revealed a blood pressure of 140/90 mm Hg (taking ramipril 5 mg per day) and heart rate was 82 beats/min. No visual field defect was found and galactorrhea was not present.Endocrine evaluation confirmed acromegaly. An oral glucose tolerance test (OGTT) was perform...