Tumors in the suprasellar region may cause both visual and endocrinologic symptoms. This association, well known to modern physicians, was established during the 19th century. However, we have identified a 16th-century autopsy report, written by the Dutch professor of anatomy Pieter Pauw (1564-1617), which describes an 18-year-old girl who developed marked polyuria and subsequently became totally blind from a cystic tumor compressing the optic chiasm. Based on prevailing theories on the nature of diabetes, Pauw attributed the disease to the kidneys. Undoubtedly, however, his lucid report is the earliest known account of diabetes insipidus caused by an arachnoid cyst, the Rathke cleft cyst, or craniopharyngioma in the region of the pouch of Rathke. The description also gives insights into the role of anatomic dissections in late 16th-century northern Europe.