English: Skull of a 25-year old man showing enlargement due to hydrocephalus. The specimen is from the Hunterian Museum at the Royal College of Surgeons of England.

This specimen was part of the collection of the surgeon Robert Liston (1794-1847). It was given to the College in 1842.

Hydrocephalus in an abnormal acumulation of cerebrospinal fluid within cavities inside the brain. This can cause enlargement of the skull in young children while the bones of the skull are still growing. In this case, the condition persisted into early adulthood. It was associated with osteomalacia or 'adult rickets' resulting from vitamin D deficiency.

The remainder of the skeleton was also preserved in the museum but was destroyed in 1941.