Growth hormone pituitary microadenoma - gigantism

Case contributed by Frank Gaillard


Tall, 215 cm in height.

Patient Data

Age: 16 years
Gender: Male

Within the left side of the pituitary is an ovoid region of hypoenhancement, best seen on dynamic contrast enhanced views, resulting in deviation of the infundibulum towards the right, and upward convexity of the gland. There is no evidence of invasion of the cavernous sinus. The optic chiasm is not compressed.

Conclusion: Features consistent with a pituitary microadenoma, in this clinical setting presumably a growth hormone secreting adenoma.

The skull demonstrates hyperpneumatization of the paranasal sinuses and temporal bones. 

Left hand (bone age)


The bone age matches the reference standard for males at 18 years (Greulich and Pyle). The distal radial epiphysis has not quite fused and all other epiphyses have fused.

Case Discussion

In skeletally mature individuals, a growth hormone secreting adenoma results in acromegaly. In the skeletally immature, in whom long bones can continue to grow, gigantism is the result. 

The patient went on to have a transsphenoidal resection. 


MICROSCOPIC DESCRIPTION: The sections show a moderately cellular pituitary adenoma comprising sheets and nests, surrounded by vascularized stroma. The tumor cells have mildly enlarged round nuclei, finely granular chromatin and moderate amounts of eosinophilic cytoplasm. There are no atypical features. Normal anterior pituitary gland tissue is present in specimen 5. About 80% of the tumor cells are positive for growth hormone immunostain with weak to moderate intensity. About 20% of the tumor cells are also prolactin positive with moderate intensity. The Ki-67 is 1-2%. Immunostains for the other pituitary hormones are negative.


Growth hormone secreting pituitary microadenoma.

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