Why can gigantism continue to grow after bone epiphyseal closure?

Gigantism is a condition caused by excessive secretion of growth hormone, usually due to a pituitary adenoma. The reasons why individuals with gigantism continue to grow even after skeletal maturation may include abnormal growth hormone secretion, open epiphyseal growth plates, reduced bone density, delayed surgery or treatment, and soft tissue enlargement. Specific explanations are as follows:

1. Abnormal growth hormone secretion: Pituitary adenomas can lead to increased secretion of growth hormone, which stimulates the epiphyseal growth plates to remain active, allowing bones to continue growing.

2. Open epiphyseal growth plates: In adolescence, the epiphyseal plates in human bones typically close, marking the end of height growth. However, in patients with gigantism, abnormal growth hormone secretion may keep these growth plates open, enabling continued skeletal growth.

3. Reduced bone density: Growth hormone not only promotes linear bone growth but also reduces bone mineral density. As a result, even if the growth plates close, bones may become fragile and prone to fractures, which can affect overall height and physical stability.

4. Delayed surgery or treatment: Some patients with gigantism may undergo surgery or receive medical treatment soon after diagnosis to control growth hormone levels. However, if treatment is delayed, excessive skeletal growth may have already occurred before therapy begins.

5. Soft tissue enlargement: In addition to bone growth, excess growth hormone also causes enlargement of soft tissues, including internal organs and skin. This contributes to the continued physical growth observed in individuals with gigantism.

Gigantism is a serious medical condition requiring prompt clinical management. Early medical intervention, diagnosis, and treatment are crucial to controlling excessive growth and reducing health risks associated with the disease.