Gigantism and acromegaly are endocrinological conditions of the greatest antiquity. While mythology and literature abounds with descriptions of giants, the oldest reported palaeopathological cases are remains of a person with acromegaly from 9500 to 11 500 years ago found in New Mexico, USA, and remains of a giant with signs of acromegaly from ancient Egypt (Giza; c 2425 BCE [5th Dynasty]).
In 1901, a skeleton was found in the Mastaba K2 tomb near Beit Khallaf, Egypt, which is estimated to date from the 3rd Dynasty (c 2700 BCE). The remains are of a very tall man (about 187 cm) and are attributed to King Sa-Nakht, who was an ephemeral king of Egypt during the 3rd Dynasty. It is far from certain whether the remains are really those of King Sa-Nakht, but for the medical assessment of potential gigantism this case has a great value as it could be the oldest known case. The original reports of when the skeleton was found in 1901 gave no definitive diagnosis of either acromegaly or gigantism—both conditions having then already been described in the medical literature—although the case is described several times in general terms in the endocrinological literature.,
The Lancet Diabetes and Endocrinology
Erasmus MC: University Medical Center Rotterdam

Galassi, F. M., Henneberg, M., de Herder, W., Rühli, F., & Habicht, M. E. (2017). Oldest case of gigantism? Assessment of the alleged remains of Sa-Nakht, king of ancient Egypt. The Lancet Diabetes and Endocrinology, 5(8), 580–581. doi:10.1016/S2213-8587(17)30171-7