Abstract
Acromegaly is a rare disease, usually caused by a pituitary tumor. It typically exhibits slow evolution and can result in numerous complications. In the present case report, the patient presented with hyperthyroidism associated with ophthalmopathy and right nodular goiter. The laboratory tests revealed persistent high levels of phosphorus without an apparent cause. After ruling out common pathologies associated with this finding, a focus was placed on the clinical aspects associated with acromegaly, a rare cause of hyperphosphatemia. Laboratory tests and MRI confirmed the diagnosis. The patient underwent transsphenoidal surgery, but the disease remained active, thus medical treatment was initiated, to a poor initial response. Associated with acromegaly, two distinct thyroid pathologies were diagnosed: Toxic adenoma and Graves' disease. This case highlights the challenges in diagnosing and managing a rare endocrine pathology.