Melanomas More Condition_symptoms Photos Are Melanomas On Grey Horses Malignant?

Are melanomas on grey horses malignant? - melanomas more condition_symptoms photos

My friend has a flea bite mold with a lot of melanomas on the body. Some are as big as my fist. My friend (16 years) said that they are benign and which are perceived only as a nuisance. The manager (who has some words to do with horses for 60 years) that malignant and the cancer to other parts of the horse. Who's right?