Somatomammotropinoma is a rare, mixed, functioning pituitary adenoma characterized by the cosecretion of growth hormone and prolactin, which manifests with signs and symptoms of both acromegaly and hyperprolactinemia.

Increased thickness of the lower lip, leading to a prominent appearance of the lower lip. The height of the vermilion of the lower lip in the midline is more than 2 SD above the mean. Alternatively, an apparently increased height of the vermilion of the lower lip in the frontal view (subjective).