Endocrine Abstracts

Introduction: Acromegaly is a rare condition characterized by growth hormone (GH) excess and elevated Insulin-like growth factor 1 (IGF-I) levels attributed in the vast majority of cases to a pituitary adenoma. In rare cases, GH secretion is from an ectopic origin.

Case Presentation: We present the case of a 70-year-old patient complaining of headaches without visual symptoms. The patient had a 15-year history of sleep apnea, hypertension and diabetes. Clinical examination revealed a dysmorphic syndrome characterized by extremity enlargement, prominent forehead wrinkles, widened nasal base, prognathism, and dental arcade enlargement. The rest of the examination was unremarkable. Biochemical investigation showed an elevated IGF-1 level of 757 ng/mL. GH during an oral glucose tolerance test was 3.1 ng/ml, confirming the diagnosis of acromegaly. Pituitary MRI revealed a right temporoparietal expansive process corresponding to a meningioma measuring 28×32×27 mm. The pituitary gland was normal, without a visible adenoma. The GHRH assay returned normal at 40 ng/l. A whole-body CT scan revealed no abnormalities except for a compressive right temporoparietal meningioma. Octreoscan showed intense fixation at the ileo-caecal junction, and the meningioma exhibited moderate fixation. Colonoscopy revealed no abnormalities, and several biopsies of the ileo-caecal junction returned normal. The decision was to put the patient on somatostatin analogs for the treatment of acromegaly and not to operate the meningioma due to the high surgical risk.

Discussion: In cases of biologically confirmed acromegaly where no pituitary adenoma is detected, pituitary MRI is the initial examination. Ectopic acromegaly, comprising less than 1% of cases, typically results from ectopic GHRH secretion. They are often associated with pulmonary or pancreatic neuroendocrine tumors. However, GHRH levels in our patient were normal, indicating a rare case of acromegaly due to ectopic GH secretion, with only 19 cases reported in the literature. Octreoscan identified two fixation sites, with the meningioma’s fixation being non-specific due to somatostatin receptors. The second fixation at the ileo-caecal junction suggests ectopic GH secretion by a digestive neuroendocrine tumor. Nevertheless, colonoscopy and biopsy revealed no abnormalities.