Glass Sponge is white and clear. Hence the name glass sponge

A nevus in the antecubital area is a mole on the inside of the elbow.

West Nile Virus

White Piedra

Wilms Tumor (cancer of childhood)

Waldenstrom macroalbuminuria

Whiplash (more of an injury than a disease)

Werdnig-Hoffman disease

Williams syndrome

Wilsons Disease

West Syndrome (some would say a syndrome is not a disease)

White Sponge Nevus

Wooly hair nevus

Weber-Christian disease

Winchester Syndrome

Wrinkly skin syndrome

Wildervanck syndrome

Waardenburg Syndrome

Woronoff's Ring

Wende-Bauckus Syndrome

Watson syndrome

Nevus if it is noncancerous (it's also used for birthmarks)

Nevus pigmentosus or macula

He's a yellow sponge with a white shirt, red tie and brown trousers