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Acromegaly: Identifying Clinical Signs and Differentiating from Gigantism with IGF-1 Testing

Middle-aged Caucasian patient exhibiting characteristic coarse facial features of acromegaly, including a prominent jaw and enlarged nose, seated in a medical consultation. A middle-aged Hispanic female doctor explains something with a friendly expression while holding a medical history. The environment is professional and welcoming, emphasizing the identification of clinical signs of acromegaly and the importance of the IGF-1 test in differentiating it from gigantism.

Acromegaly is an endocrine disorder characterized by excess GH (growth hormone), leading to abnormal growth of soft tissues and bones. This excessive growth primarily manifests as coarse facial features, such as a prominent jaw and enlarged nose. Early identification of these clinical signs is crucial for the appropriate management of the disease. However, differentiating acromegaly from gigantism can be challenging, as both conditions share similar clinical characteristics.

Diving Deeper into Differentiation

Both acromegaly and gigantism are caused by the same underlying mechanism: excess GH. The main difference lies in the timing of onset. Gigantism occurs when excess GH presents before the closure of the epiphyseal plates, resulting in excessive longitudinal growth. In contrast, acromegaly develops after the closure of these plates, primarily affecting soft tissues and the bones of the skull and extremities.

To confirm a diagnosis of acromegaly, it is recommended to perform an IGF-1 test (insulin-like growth factor 1). A normal IGF-1 level suggests that the patient does not have acromegaly. If IGF-1 levels are elevated or equivocal, a GH suppression test following glucose administration should be conducted. Inadequate suppression of GH confirms the diagnosis of acromegaly. Subsequently, an MRI of the pituitary gland should be performed to identify the cause of the excess GH, which is most commonly a somatotroph adenoma [1].

It is important to consider differential diagnoses such as pachydermoperiostosis, which can mimic acromegaly, or insulin-mediated pseudoacromegaly, which presents similar physical characteristics without alterations in the somatotropic axis [2][3].

Conclusions

Accurate identification of the clinical signs of acromegaly and its differentiation from gigantism is essential for appropriate treatment. Biochemical evaluation, including the IGF-1 test, is fundamental for confirming the diagnosis and avoiding unnecessary interventions. Additionally, it is crucial to consider other conditions that may present similar characteristics, such as pseudoacromegaly associated with non-functioning pituitary adenomas [4].

References


Created 13/1/2025