Juvenile Xanthogranuloma

Juvenile Xanthogranuloma is a benign, usually asymptomatic condition of neonates and young children that almost always resolves spontaneously.  It occurs cutaneously most of the time, primarily on the head and neck but can also show up on the trunk and on the extremities.  Most of the time, they are solitary.  Although they are usually small, <5mm, they can be up to 2 cm and rarely even larger than that.  Notably, they can show up extracutaneously in the eyes, primarily in the irides.

The differential is pretty slim, including Spitz nevi, eruptive xanthomas (which are always multiple) and Langerhans Cell Histiocytosis.  

In differentiating a JXG from a Spitz Nevus, I would look at both color and texture.  The color of JXGs tends to be yellowish or yellow brown or yellow-red, whereas the Spitzes tend to be red (although they can be slightly orange in color, that's unusual) but the main differentiation is that the JXGs are really smooth and almost blister-like, such as the example I gave you, versus Spitz Nevi, which tend to have more of a texture similar to nevi. I would biopsy these just to be assured this wasn't a solitary lesion of LCH, but I would assure the parents it most likely represented a benign growth.