Penile lesions come in many shapes and sizes and are so common that there are several causes for them. Some are cause for serious concern, while others are nothing to worry about. No matter what the cause is or what danger is (or is not) involved, seeing a lesion on the penis is cause for alarm in men as their first thoughts go to sexually transmitted diseases or cancer. However, spots or lesions on the penis are rarely a sign of cancer or an STD.
There are three basic types of penile lesions; papules, plaques and ulcers. Though it is uncommon, some ulcers are caused by syphilis or cancer. Again, this is rare but is a good reason for getting checked by a medical professional. Papules are small lesions that are generally not serious though some are infectious. Some causes are ingrown hair follicles and overactive sweat glands. Plaques are also not typically dangerous, but as with papules they can be infections and turn into something serious. Two common examples of plaque lesions are eczema and psoriasis. The only sure way to know what type of lesion is present is to seek medical attention.