Silent somatotroph pituitary adenomas: an update.

Silent growth hormone adenomas (SGHA) are a rare entity of non-functioning pituitary neuroendocrine tumors. Diagnosis is invariably made post-operatively of a tumor immunopositive for GH (and Pit-1 in selected cases) but without clinical acromegaly. Mainly young females are affected, and tumors are often uncovered by investigation for headaches or oligoamenorrhea. Integration of clinical, pathological and biochemical data is required for proper diagnosis. Beside normal IGF-1 levels, a third of SGHAs displays elevated GH levels and some will eventually progress to acromegaly. Almost two-thirds will be mixed GH-prolactin tumors and sparsely-granulated monohormonal GH tumors seems the more aggressive subtype. Recurrence and need for radiation is higher than other non-functioning tumors so close follow-up is warranted.