Gigantism

Gigantism is a nonspecific term that refers to enlargement of normal body proportions and can be divided into generalised gigantism (i.e. of the whole body) or localised gigantism (i.e. affection only part of the body). 

Localised gigantism is due to a variety of causes, and is discussed separately.

The aetiology of gigantism will clearly depend on the definition. If one uses the term broadly, merely referring to height two or more standard deviation above age, gender and Tanner stage matched cohort, then most cases will merely be physiological tallness 3. In contrast, by far the most common cause of pathological gigantism is the presence of growth hormone secreting pituitary adenoma (aka pituitary gigantism), which is the  focus of the remainder of this article. 

Note: for gigantism to occur, growth hormone excess needs to occur before growth plates are fused. If this occurs later in life, then stature will not be affected and individuals develop acromegaly

The vast majority of cases of pituitary gigantism are sporadic, and diagnosed in mid to late childhood (e.g. 13 years of age 1). 

Rare genetic mutations (e.g. X-linked acrogigantism) are recognised 2

Clinical presentation is typically, not surprisingly, due to noticeable excessive height, although due to the positive societal attitude towards tall people, particularly in males, can lead to delay in investigation. 

Bone age assessment is very helpful in assessing skeletal size and maturity. 

Increased stature is fairly obvious clinically but may be inapparent on radiography. 

Cross-sectional imaging demonstrates similar features to those seen in acromegalic patients, and is discussed there. 

Treatment of gigantism can be challenging, as transsphenoidal surgery (which is considered first line therapy) often does not control growth hormone levels 1. Additional therapeutic options include medical therapy (e.g. with octreotide and/or pegvisomant) and radiotherapy 1

 

Share article

Article information

rID: 47746
Synonyms or Alternate Spellings:
  • Pituitary gigantism

Support Radiopaedia and see fewer ads

Cases and figures

  • Drag
    Case 1: hyperpneumatisation
    Drag here to reorder.
  • Updating… Please wait.
    Loadinganimation

    Alert accept

    Error Unable to process the form. Check for errors and try again.

    Alert accept Thank you for updating your details.